feat: Enhanced get template function (#513)

`get` is now able to take one more optional argument, that is used as the default value when the value for the key does not exist.

Resolves #465
Fixes #427
Fixes #357
Ref #460

.circleci/config.yml

@@ -4,7 +4,7 @@ jobs:
 
   build:
     docker:
-      - image: circleci/golang:1.10.1
+      - image: circleci/golang:1.11.2
     working_directory: /go/src/github.com/roboll/helmfile
     steps:
       - checkout
@@ -16,7 +16,7 @@ jobs:
 
   test:
     docker:
-      - image: circleci/golang:1.10.1
+      - image: circleci/golang:1.11.2
     working_directory: /go/src/github.com/roboll/helmfile
     steps:
       - checkout
@@ -26,9 +26,12 @@ jobs:
 
   # thanks to https://raw.githubusercontent.com/weaveworks/launcher/master/.circleci/config.yml
   integration_tests:
-    machine: true
+    machine:
+      image: circleci/classic:201808-01
     environment:
       CHANGE_MINIKUBE_NONE_USER: true
+      MINIKUBE_WANTUPDATENOTIFICATION: false
+      MINIKUBE_WANTREPORTERRORPROMPT: false
     steps:
       - checkout
       - run: mkdir ~/build
@@ -38,7 +41,7 @@ jobs:
       - run:
           name: Install helm
           environment:
-            HELM_VERSION: v2.9.0
+            HELM_VERSION: v2.13.0
           command: |
             HELM_FILENAME="helm-${HELM_VERSION}-linux-amd64.tar.gz"
             curl -Lo ${HELM_FILENAME} "https://kubernetes-helm.storage.googleapis.com/${HELM_FILENAME}"
@@ -49,14 +52,13 @@ jobs:
           name: Deploy minikube
           environment:
             CHANGE_MINIKUBE_NONE_USER: true
-            K8S_VERSION: v1.9.0
-            MINIKUBE_VERSION: v0.25.2
+            K8S_VERSION: v1.12.3
+            MINIKUBE_VERSION: v0.30.0
           command: |
             curl -Lo kubectl https://storage.googleapis.com/kubernetes-release/release/${K8S_VERSION}/bin/linux/amd64/kubectl
             chmod +x kubectl && sudo mv kubectl /usr/local/bin/
             curl -Lo minikube https://storage.googleapis.com/minikube/releases/${MINIKUBE_VERSION}/minikube-linux-amd64
             chmod +x minikube && sudo mv minikube /usr/local/bin/
-            sudo minikube config set WantReportErrorPrompt false
             sudo -E minikube start --vm-driver=none --kubernetes-version=${K8S_VERSION}
             sudo -E minikube update-context
       - run:
@@ -72,7 +74,7 @@ jobs:
 
   release:
     docker:
-      - image: circleci/golang:1.10.1
+      - image: circleci/golang:1.11.2
     working_directory: /go/src/github.com/roboll/helmfile
     steps:
     - checkout

CONTRIBUTING.md

@@ -0,0 +1,39 @@
+# DCO + License
+
+By contributing to `helmfile`, you accept and agree to the following DCO and license terms and
+conditions for your present and future Contributions submitted to the `helmfile` project.
+
+[DCO](https://developercertificate.org/)
+[License](https://github.com/roboll/helmfile/blob/master/LICENSE)
+
+# Developing helmfile
+
+Locate your `GOPATH`, usually `~/go`, and run:
+
+```console
+$ go get github.com/roboll/helmfile
+
+$ cd $GOPATH/src/github.com/roboll/helmfile
+
+$ git checkout -b your-shiny-new-feature origin/master
+
+...
+
+$ git commit -m 'feat: do whatever for whatever purpose
+
+This adds ... by:
+
+- Adding ...
+- Changing ...
+- Removing...
+
+Resolves #ISSUE_NUMBER
+'
+
+$ hub fork
+$ git push YOUR_GITHUB_USER your-shiny-new-feature
+$ hub pull-request
+```
+
+Note that the above tutorial uses [hub](https://github.com/github/hub) just for ease of explanation.
+Please use whatever tool or way to author your pull request!

Dockerfile

@@ -1,4 +1,4 @@
-FROM golang:1.10.1-alpine3.7 as builder
+FROM golang:1.11.2-alpine3.8 as builder
 
 RUN apk add --no-cache make git
 WORKDIR /go/src/github.com/roboll/helmfile/
@@ -7,14 +7,14 @@ RUN make static-linux
 
 # -----------------------------------------------------------------------------
 
-FROM alpine:3.7
+FROM alpine:3.8
 
 RUN apk add --no-cache ca-certificates git bash curl
 
-ARG HELM_VERSION=v2.10.0
+ARG HELM_VERSION=v2.13.0
 ARG HELM_LOCATION="https://kubernetes-helm.storage.googleapis.com"
 ARG HELM_FILENAME="helm-${HELM_VERSION}-linux-amd64.tar.gz"
-ARG HELM_SHA256="0fa2ed4983b1e4a3f90f776d08b88b0c73fd83f305b5b634175cb15e61342ffe"
+ARG HELM_SHA256="15eca6ad225a8279de80c7ced42305e24bc5ac60bb7d96f2d2fa4af86e02c794"
 RUN wget ${HELM_LOCATION}/${HELM_FILENAME} && \
     sha256sum ${HELM_FILENAME} | grep -q "${HELM_SHA256}" && \
     tar zxf ${HELM_FILENAME} && mv /linux-amd64/helm /usr/local/bin/ && \

Gopkg.lock

@@ -2,59 +2,78 @@
 
 
 [[projects]]
+  digest = "1:d9141c149f722217d35834972878499a4781fe5ae46a152e8ac843ff15efc80f"
   name = "github.com/Masterminds/semver"
   packages = ["."]
+  pruneopts = "UT"
   revision = "8d82589cda2d7b5b9167396841975c4535c9bec6"
   version = "v1.4.1"
 
 [[projects]]
+  digest = "1:46a054a232ea2b7f0a35398d682b433d26ba9975fce9197b1784824402059f5b"
   name = "github.com/Masterminds/sprig"
   packages = ["."]
+  pruneopts = "UT"
   revision = "6b2a58267f6a8b1dc8e2eb5519b984008fa85e8c"
   version = "v2.15.0"
 
 [[projects]]
+  digest = "1:8f5416c7f59da8600725ae1ff00a99af1da8b04c211ae6f3c8f8bcab0164f650"
   name = "github.com/aokoli/goutils"
   packages = ["."]
+  pruneopts = "UT"
   revision = "3391d3790d23d03408670993e957e8f408993c34"
   version = "v1.0.1"
 
 [[projects]]
+  digest = "1:8f8811f9be822914c3a25c6a071e93beb4c805d7b026cbf298bc577bc1cc945b"
   name = "github.com/google/uuid"
   packages = ["."]
+  pruneopts = "UT"
   revision = "064e2069ce9c359c118179501254f67d7d37ba24"
   version = "0.2"
 
 [[projects]]
+  digest = "1:6b1e7618931d0ed9a17fec1c1d84271907aa61172c50b8272327f6cd4fafb650"
   name = "github.com/huandu/xstrings"
   packages = ["."]
+  pruneopts = "UT"
   revision = "2bf18b218c51864a87384c06996e40ff9dcff8e1"
   version = "v1.0.0"
 
 [[projects]]
+  digest = "1:8eb1de8112c9924d59bf1d3e5c26f5eaa2bfc2a5fcbb92dc1c2e4546d695f277"
   name = "github.com/imdario/mergo"
   packages = ["."]
-  revision = "9d5f1277e9a8ed20c3684bda8fde67c05628518c"
-  version = "v0.3.4"
+  pruneopts = "UT"
+  revision = "9f23e2d6bd2a77f959b2bf6acdbefd708a83a4a4"
+  version = "v0.3.6"
 
 [[projects]]
+  digest = "1:55d0f7127962b0657acfd69650634057b3a08958226feee1b64a379666bb915e"
   name = "github.com/urfave/cli"
   packages = ["."]
+  pruneopts = "UT"
   revision = "6011f165dc288c72abd8acd7722f837c5c64198d"
 
 [[projects]]
+  digest = "1:3c1a69cdae3501bf75e76d0d86dc6f2b0a7421bc205c0cb7b96b19eed464a34d"
   name = "go.uber.org/atomic"
   packages = ["."]
+  pruneopts = "UT"
   revision = "1ea20fb1cbb1cc08cbd0d913a96dead89aa18289"
   version = "v1.3.2"
 
 [[projects]]
+  digest = "1:60bf2a5e347af463c42ed31a493d817f8a72f102543060ed992754e689805d1a"
   name = "go.uber.org/multierr"
   packages = ["."]
+  pruneopts = "UT"
   revision = "3c4937480c32f4c13a875a1829af76c98ca3d40a"
   version = "v1.1.0"
 
 [[projects]]
+  digest = "1:9580b1b079114140ade8cec957685344d14f00119e0241f6b369633cb346eeb3"
   name = "go.uber.org/zap"
   packages = [
     ".",
@@ -62,29 +81,41 @@
     "internal/bufferpool",
     "internal/color",
     "internal/exit",
-    "zapcore"
+    "zapcore",
   ]
+  pruneopts = "UT"
   revision = "eeedf312bc6c57391d84767a4cd413f02a917974"
   version = "v1.8.0"
 
 [[projects]]
   branch = "master"
+  digest = "1:7b1c378a71f617ec07229a1fcbb90b6a5344295823e1d732398f50fd9ae4bbec"
   name = "golang.org/x/crypto"
   packages = [
     "pbkdf2",
-    "scrypt"
+    "scrypt",
   ]
+  pruneopts = "UT"
   revision = "b2aa35443fbc700ab74c586ae79b81c171851023"
 
 [[projects]]
+  branch = "v2"
+  digest = "1:342378ac4dcb378a5448dd723f0784ae519383532f5e70ade24132c4c8693202"
   name = "gopkg.in/yaml.v2"
   packages = ["."]
+  pruneopts = "UT"
   revision = "5420a8b6744d3b0345ab293f6fcba19c978f1183"
-  version = "v2.2.1"
 
 [solve-meta]
   analyzer-name = "dep"
   analyzer-version = 1
-  inputs-digest = "b1f000751afc0a44973307c69b6a4b8e8c1b807fd9881a13f370c30fcbcab7a2"
+  input-imports = [
+    "github.com/Masterminds/sprig",
+    "github.com/imdario/mergo",
+    "github.com/urfave/cli",
+    "go.uber.org/zap",
+    "go.uber.org/zap/zapcore",
+    "gopkg.in/yaml.v2",
+  ]
   solver-name = "gps-cdcl"
   solver-version = 1

Gopkg.toml

@@ -12,4 +12,4 @@
 
 [[constraint]]
   name = "github.com/imdario/mergo"
-  version = "0.3.4"
+  version = "0.3.6"

Makefile

@@ -33,6 +33,10 @@ static-linux:
 	env CGO_ENABLED=0 GOOS=linux GOARCH=amd64 go build -o "dist/helmfile_linux_amd64" -ldflags '-X main.Version=${TAG}' ${TARGETS}
 .PHONY: linux
 
+install:
+	env CGO_ENABLED=0 go install -ldflags '-X main.Version=${TAG}' ${TARGETS}
+.PHONY: install
+
 clean:
 	rm dist/helmfile_*
 .PHONY: clean
@@ -61,3 +65,19 @@ tools:
 TAG  = $(shell git describe --tags --abbrev=0 HEAD)
 LAST = $(shell git describe --tags --abbrev=0 HEAD^)
 BODY = "`git log ${LAST}..HEAD --oneline --decorate` `printf '\n\#\#\# [Build Info](${BUILD_URL})'`"
+
+release/minor:
+	git checkout master
+	git pull --rebase origin master
+	bash -c 'if git branch | grep autorelease; then git branch -D autorelease; else echo no branch to be cleaned; fi'
+	git checkout -b autorelease origin/master
+	bash -c 'SEMTAG_REMOTE=origin hack/semtag final -s minor'
+	git checkout master
+
+release/patch:
+	git checkout master
+	git pull --rebase origin master
+	bash -c 'if git branch | grep autorelease; then git branch -D autorelease; else echo no branch to be cleaned; fi'
+	git checkout -b autorelease origin/master
+	bash -c 'SEMTAG_REMOTE=origin hack/semtag final -s patch'
+	git checkout master

README.md

@@ -24,7 +24,7 @@ To avoid upgrades for each iteration of `helm`, the `helmfile` executable delega
 
 ## configuration syntax
 
-**CAUTION**: This documentation is for the development version of helmfile. If you are looking for the documentation for any of releases, please switch to the corresponding release tag like [v0.31.0](https://github.com/roboll/helmfile/tree/v0.31.0).
+**CAUTION**: This documentation is for the development version of Helmfile. If you are looking for the documentation for any of releases, please switch to the corresponding release tag like [v0.31.0](https://github.com/roboll/helmfile/tree/v0.31.0).
 
 The default helmfile is `helmfile.yaml`:
 
@@ -37,12 +37,12 @@ repositories:
     username: optional_username
     password: optional_password
 
-context: kube-context					 # kube-context (--kube-context)
+# context: kube-context # this directive is deprecated, please consider using helmDefaults.kubeContext
 
-#default values to set for args along with dedicated keys that can be set by contributers, cli args take precedence overe these
+#default values to set for args along with dedicated keys that can be set by contributers, cli args take precedence over these
 helmDefaults:
   tillerNamespace: tiller-namespace  #dedicated default key for tiller-namespace
-  kubeContext: kube-context          #dedicated default key for kube-context
+  kubeContext: kube-context          #dedicated default key for kube-context (--kube-context)
   # additional and global args passed to helm
   args:
     - "--set k=v"
@@ -97,11 +97,15 @@ releases:
     recreatePods: true
     # forces resource update through delete/recreate if needed
     force: true
+    # set `false` to uninstall on sync
+    installed: true
+    # restores previous state in case of failed release
+    atomic: true
 
   # Local chart example
   - name: grafana                            # name of this release
     namespace: another                       # target namespace
-    chart: ../my-charts/grafana              # the chart being installed to create this release, referenced by relative path to local chart
+    chart: ../my-charts/grafana              # the chart being installed to create this release, referenced by relative path to local helmfile
     values:
     - "../../my-values/grafana/values.yaml"             # Values file (relative path to manifest)
     - ./values/{{ requiredEnv "PLATFORM_ENV" }}/config.yaml # Values file taken from path with environment variable. $PLATFORM_ENV must be set in the calling environment.
@@ -147,9 +151,11 @@ releases:
 
 ## installation
 
-- `go get github.com/roboll/helmfile` or
 - download one of [releases](https://github.com/roboll/helmfile/releases) or
-- run as a [container](https://quay.io/roboll/helmfile)
+- run as a [container](https://quay.io/roboll/helmfile) or
+- install from [AUR](https://aur.archlinux.org/packages/kubernetes-helmfile-bin/) for Archlinux or
+- Windows (using [scoop](https://scoop.sh/)): `scoop install helmfile`
+- macOS (using [homebrew](https://brew.sh/)): `brew install helmfile`
 
 ## getting started
 
@@ -170,12 +176,16 @@ releases:
 Sync your Kubernetes cluster state to the desired one by running:
 
 ```console
-helmfile sync
+helmfile apply
 ```
 
 Congratulations! You now have your first Prometheus deployment running inside your cluster.
 
-Iterate on the `helmfile.yaml` by referencing the [configuration syntax](#configuration-syntax) and the [cli reference](#cli-reference).
+Iterate on the `helmfile.yaml` by referencing:
+
+- [Configuration syntax](#configuration-syntax)
+- [CLI reference](#cli-reference).
+- [Helmfile Best Practices Guide](https://github.com/roboll/helmfile/blob/master/docs/writing-helmfile.md)
 
 ## cli reference
 
@@ -187,19 +197,21 @@ USAGE:
    helmfile [global options] command [command options] [arguments...]
 
 COMMANDS:
-     repos   sync repositories from state file (helm repo add && helm repo update)
-     charts  sync releases from state file (helm upgrade --install)
-     diff    diff releases from state file against env (helm diff)
-     lint    lint charts from state file (helm lint)
-     sync    sync all resources from state file (repos, releases and chart deps)
-     apply   apply all resources from state file only when there are changes
-     status  retrieve status of releases in state file
-     delete  delete releases from state file (helm delete)
-     test    test releases from state file (helm test)
+     repos     sync repositories from state file (helm repo add && helm repo update)
+     charts    sync releases from state file (helm upgrade --install)
+     diff      diff releases from state file against env (helm diff)
+     template  template releases from state file against env (helm template)
+     lint      lint charts from state file (helm lint)
+     sync      sync all resources from state file (repos, releases and chart deps)
+     apply     apply all resources from state file only when there are changes
+     status    retrieve status of releases in state file
+     delete    delete releases from state file (helm delete)
+     test      test releases from state file (helm test)
 
 GLOBAL OPTIONS:
    --helm-binary value, -b value           path to helm binary
    --file helmfile.yaml, -f helmfile.yaml  load config from file or directory. defaults to helmfile.yaml or `helmfile.d`(means `helmfile.d/*.yaml`) in this preference
+   --environment default, -e default       specify the environment name. defaults to default
    --quiet, -q                             Silence output. Equivalent to log-level warn
    --kube-context value                    Set kubectl context. Uses current context by default
    --log-level value                       Set log level, default info
@@ -208,6 +220,7 @@ GLOBAL OPTIONS:
                                            A release must match all labels in a group in order to be used. Multiple groups can be specified at once.
                                            --selector tier=frontend,tier!=proxy --selector tier=backend. Will match all frontend, non-proxy releases AND all backend releases.
                                            The name of a release can be used as a label. --selector name=myrelease
+   --interactive, -i                       Request confirmation before attempting to modify clusters
    --help, -h                              show help
    --version, -v                           print the version
 ```
@@ -232,13 +245,15 @@ please look at their [documentation](https://github.com/databus23/helm-diff#helm
 
 ### apply
 
-The `helmfile apply` sub-command begins by executing `diff`. If `diff` finds that there is any changes, `sync` is executed after prompting you for an confirmation. `--auto-approve` skips the confirmation.
+The `helmfile apply` sub-command begins by executing `diff`. If `diff` finds that there is any changes, `sync` is executed. Adding `--interactive` instructs Helmfile to request your confirmation before `sync`.
 
 An expected use-case of `apply` is to schedule it to run periodically, so that you can auto-fix skews between the desired and the current state of your apps running on Kubernetes clusters.
 
 ### delete
 
-The `helmfile delete` sub-command deletes all the releases defined in the manfiests
+The `helmfile delete` sub-command deletes all the releases defined in the manifests.
+
+`helmfile --interactive delete` instructs Helmfile to request your confirmation before actually deleting releases.
 
 Note that `delete` doesn't purge releases. So `helmfile delete && helmfile sync` results in sync failed due to that releases names are not deleted but preserved for future references. If you really want to remove releases for reuse, add `--purge` flag to run it like `helmfile delete --purge`.
 
@@ -266,13 +281,13 @@ Using manifest files in conjunction with command line argument can be a bit conf
 A few rules to clear up this ambiguity:
 
 - Absolute paths are always resolved as absolute paths
-- Relative paths referenced *in* the helmfile manifest itself are relative to that manifest
+- Relative paths referenced *in* the Helmfile manifest itself are relative to that manifest
 - Relative paths referenced on the command line are relative to the current working directory the user is in
 
 For additional context, take a look at [paths examples](PATHS.md)
 
 ## Labels Overview
-A selector can be used to only target a subset of releases when running helmfile. This is useful for large helmfiles with releases that are logically grouped together.
+A selector can be used to only target a subset of releases when running Helmfile. This is useful for large helmfiles with releases that are logically grouped together.
 
 Labels are simple key value pairs that are an optional field of the release spec. When selecting by label, the search can be inverted. `tier!=backend` would match all releases that do NOT have the `tier: backend` label. `tier=fronted` would only match releases with the `tier: frontend` label.
 
@@ -282,6 +297,8 @@ The `selector` parameter can be specified multiple times. Each parameter is reso
 
 `--selector tier=frontend --selector tier=backend` will select all the charts
 
+In addition to user supplied labels the name, namespace, and chart are available to be used as selectors.  The chart will just be the chart name excluding the repository (Example `stable/filebeat` would be selected using `--selector chart=filebeat`).
+
 ## Templates
 
 You can use go's text/template expressions in `helmfile.yaml` and `values.yaml.gotmpl` (templated helm values files). `values.yaml` references will be used verbatim. In other words:
@@ -293,7 +310,7 @@ In addition to built-in ones, the following custom template functions are availa
 
 - `readFile` reads the specified local file and generate a golang string
 - `fromYaml` reads a golang string and generates a map
-- `setValuleAtPath PATH NEW_VALUE` traverses a golang map, replaces the value at the PATH with NEW_VALUE
+- `setValueAtPath PATH NEW_VALUE` traverses a golang map, replaces the value at the PATH with NEW_VALUE
 - `toYaml` marshals a map into a string
 
 ### Values Files Templates
@@ -308,7 +325,7 @@ releases
   - values.yaml.gotmpl
 ```
 
-Every values file whose file extension is `.gotmpl` is considered as a tempalte file.
+Every values file whose file extension is `.gotmpl` is considered as a template file.
 
 Suppose `values.yaml.gotmpl` was something like:
 
@@ -397,7 +414,7 @@ environments:
 
 releases:
 
-{{ if (eq .Environment.Name "production" }}
+{{ if eq .Environment.Name "production" }}
 - name: newrelic-agent
   # snip
 {{ end }}
@@ -436,7 +453,7 @@ releaseName: prod
 `values.yaml.gotmpl`
 
 ```yaml
-domain: {{ .Environment.Values.domain | default "dev.example.com" }}
+domain: {{ .Environment.Values | getOrNil "my.domain" | default "dev.example.com" }}
 ```
 
 `helmfile sync` installs `myapp` with the value `domain=dev.example.com`,
@@ -476,17 +493,27 @@ releases:
 
 ## Environment Secrets
 
-Environment Secrets are encrypted versions of `Environment Values`.
+Environment Secrets (not to be confused with Kubernetes Secrets) are encrypted versions of `Environment Values`.
 You can list any number of `secrets.yaml` files created using `helm secrets` or `sops`, so that
-helmfile could automatically decrypt and merge the secrets into the environment values.
+Helmfile could automatically decrypt and merge the secrets into the environment values.
 
-Suppose you have environment secrets defined in `hemlfile.yaml`:
+First you must have the [helm-secrets](https://github.com/futuresimple/helm-secrets) plugin installed along with a
+`.sops.yaml` file to configure the method of encryption (this can be in the same directory as your helmfile or
+in the sub-directory containing your secrets files).
 
+Then suppose you have a a foo.bar secret defined in `environments/production/secrets.yaml`:
+```yaml
+foo.bar: "mysupersecretstring"
+```
+
+You can then encrypt it with `helm secrets enc environments/production/secrets.yaml`
+
+Then reference that encrypted file in `helmfile.yaml`:
 ```yaml
 environments:
   production:
     secrets:
-    - environments/produdction/secrets.yaml
+    - environments/production/secrets.yaml
 
 releases:
 - name: myapp
@@ -495,13 +522,12 @@ releases:
   - values.yaml.gotmpl
 ```
 
-an environment secret `foo.bar` can be referenced by the below template expression in your `values.yaml.gotmpl`:
+Then the environment secret `foo.bar` can be referenced by the below template expression in your `values.yaml.gotmpl`:
 
 ```yaml
-{{ .Values.foo.bar }
+{{ .Environment.Values.foo.bar }}
 ```
 
-
 ## Separating helmfile.yaml into multiple independent files
 
 Once your `helmfile.yaml` got to contain too many releases,
@@ -530,7 +556,7 @@ All the yaml files under the specified directory are processed in the alphabetic
 
 In case you want more control over how multiple `helmfile.yaml` files are organized, use `helmfiles:` configuration key in the `helmfile.yaml`:
 
-Suppose you have multiple microservices organized in a Git reposistory that looks like:
+Suppose you have multiple microservices organized in a Git repository that looks like:
 
 - `myteam/` (sometimes it is equivalent to a k8s ns, that is `kube-system` for `clusterops` team)
   - `apps/`
@@ -558,7 +584,7 @@ for d in apps/*; do helmfile -f $d diff; if [ $? -eq 2 ]; then helmfile -f $d sy
 
 At this point, you'll start writing a `Makefile` under `myteam/` so that `make sync-all` will do the job.
 
-It does work, but you can rely on the helmfile's feature instead.
+It does work, but you can rely on the Helmfile feature instead.
 
 Put `myteam/helmfile.yaml` that looks like:
 
@@ -593,9 +619,120 @@ mysetting: |
 
 The possibility is endless. Try importing values from your golang app, bash script, jsonnet, or anything!
 
+## Hooks
+
+A Helmfile hook is a per-release extension point that is composed of:
+
+- `events`
+- `command`
+- `args`
+
+Helmfile triggers various `events` while it is running.
+Once `events` are triggered, associated `hooks` are executed, by running the `command` with `args`.
+
+Currently supported `events` are:
+
+- `prepare`
+- `cleanup`
+
+Hooks associated to `prepare` events are triggered after each release in your helmfile is loaded from YAML, before execution.
+
+Hooks associated to `cleanup` events are triggered after each release is processed.
+
+The following is an example hook that just prints the contextual information provided to hook:
+
+```
+releases:
+- name: myapp
+  chart: mychart
+  # *snip*
+  hooks:
+  - events: ["prepare", "cleanup"]
+    command: "echo"
+    args: ["{{`{{.Environment.Name}}`}}", "{{`{{.Release.Name}}`}}", "{{`{{.HelmfileCommand}}`}}\
+"]
+```
+
+Let's say you ran `helmfile --environment prod sync`, the above hook results in executing:
+
+```
+echo {{Environment.Name}} {{.Release.Name}} {{.HelmfileCommand}}
+```
+
+Whereas the template expressions are executed thus the command becomes:
+
+```
+echo prod myapp sync
+```
+
+Now, replace `echo` with any command you like, and rewrite `args` that actually conforms to the command, so that you can integrate any command that does:
+
+- templating
+- linting
+- testing
+
+For templating, imagine that you created a hook that generates a helm chart on-the-fly by running an external tool like ksonnet, kustomize, or your own template engine.
+It will allow you to write your helm releases with any language you like, while still leveraging goodies provided by helm.
+
+### Helmfile + Kustomize
+
+Do you prefer `kustomize` to write and organize your Kubernetes apps, but still want to leverage helm's useful features
+like rollback, history, and so on? This section is for you!
+
+The combination of `hooks` and [helmify-kustomize](https://gist.github.com/mumoshu/f9d0bd98e0eb77f636f79fc2fb130690)
+enables you to integrate [kustomize](https://github.com/kubernetes-sigs/kustomize) into Helmfile.
+
+That is, you can use `kustommize` to build a local helm chart from a kustomize overlay.
+
+Let's assume you have a kustomize project named `foo-kustomize` like this:
+
+```
+foo-kustomize/
+├── base
+│   ├── configMap.yaml
+│   ├── deployment.yaml
+│   ├── kustomization.yaml
+│   └── service.yaml
+└── overlays
+    ├── default
+    │   ├── kustomization.yaml
+    │   └── map.yaml
+    ├── production
+    │   ├── deployment.yaml
+    │   └── kustomization.yaml
+    └── staging
+        ├── kustomization.yaml
+        └── map.yaml
+
+5 directories, 10 files
+```
+
+Write `helmfile.yaml`:
+
+```yaml
+- name: kustomize
+  chart: ./foo
+  hooks:
+  - events: ["prepare", "cleanup"]
+    command: "../helmify"
+    args: ["{{`{{if eq .Event.Name \"prepare\"}}build{{else}}clean{{end}}`}}", "{{`{{.Release.Ch\
+art}}`}}", "{{`{{.Environment.Name}}`}}"]
+```
+
+Run `helmfile --environment staging sync` and see it results in helmfile running `kustomize build foo-kustomize/overlays/staging > foo/templates/all.yaml`.
+
+Voilà! You can mix helm releases that are backed by remote charts, local charts, and even kustomize overlays.
+
+## Guides
+
+Use the [Helmfile Best Practices Guide](/docs/writing-helmfile.md) to write advanced helmfiles that feature:
+
+- Default values
+- Layering
+
 ## Using env files
 
-helmfile itself doesn't have an ability to load env files. But you can write some bash script to achieve the goal:
+Helmfile itself doesn't have an ability to load env files. But you can write some bash script to achieve the goal:
 
 ```console
 set -a; . .env; set +a; helmfile sync
@@ -603,7 +740,15 @@ set -a; . .env; set +a; helmfile sync
 
 Please see #203 for more context.
 
-## Running helmfile without an Internet connection
+## Running helmfile interactively
+
+`helmfile --interactive [apply|delete]` requests confirmation from you before actually modifying your cluster.
+
+Use it when you're running `helmfile` manually on your local machine or a kind of secure administrative hosts.
+
+For your local use-case, aliasing it like `alias hi='helmfile --interactive'` would be convenient.
+
+## Running Helmfile without an Internet connection
 
 Once you download all required charts into your machine, you can run `helmfile charts` to deploy your apps.
 It basically run only `helm upgrade --install` with your already-downloaded charts, hence no Internet connection is required.
@@ -612,4 +757,10 @@ See #155 for more information on this topic.
 
 ## Examples
 
-For more examples, see the [examples/README.md](https://github.com/roboll/helmfile/blob/master/examples/README.md) or the [`helmfile.d`](https://github.com/cloudposse/helmfiles/tree/master/helmfile.d) distribution of helmfiles by [Cloud Posse](https://github.com/cloudposse/).
+For more examples, see the [examples/README.md](https://github.com/roboll/helmfile/blob/master/examples/README.md) or the [`helmfile`](https://github.com/cloudposse/helmfiles/tree/master/releases) distribution by [Cloud Posse](https://github.com/cloudposse/).
+
+# Attribution
+
+We use:
+
+- [semtag](https://github.com/pnikosis/semtag) for automated semver tagging. I greatly appreciate the author(pnikosis)'s effort on creating it and their kindness to share it!

app_test.go

@@ -1,413 +0,0 @@
-package main
-
-import (
-	"fmt"
-	"github.com/roboll/helmfile/helmexec"
-	"github.com/roboll/helmfile/state"
-	"os"
-	"reflect"
-	"testing"
-)
-
-// See https://github.com/roboll/helmfile/issues/193
-func TestFindAndIterateOverDesiredStates(t *testing.T) {
-	absPaths := map[string]string{
-		".": "/path/to",
-		"/path/to/helmfile.d": "/path/to/helmfile.d",
-	}
-	dirs := map[string]bool{
-		"helmfile.d": true,
-	}
-	files := map[string]string{
-		"helmfile.yaml": `
-helmfiles:
-- helmfile.d/a*.yaml
-- helmfile.d/b*.yaml
-`,
-		"/path/to/helmfile.d/a1.yaml": `
-releases:
-- name: zipkin
-  chart: stable/zipkin
-`,
-		"/path/to/helmfile.d/a2.yaml": `
-releases:
-- name: prometheus
-  chart: stable/prometheus
-`,
-		"/path/to/helmfile.d/b.yaml": `
-releases:
-- name: grafana
-  chart: stable/grafana
-`,
-	}
-	globMatches := map[string][]string{
-		"/path/to/helmfile.d/a*.yaml": []string{"/path/to/helmfile.d/a1.yaml", "/path/to/helmfile.d/a2.yaml"},
-		"/path/to/helmfile.d/b*.yaml": []string{"/path/to/helmfile.d/b.yaml"},
-	}
-	fileExistsAt := func(path string) bool {
-		_, ok := files[path]
-		return ok
-	}
-	directoryExistsAt := func(path string) bool {
-		_, ok := dirs[path]
-		return ok
-	}
-	readFile := func(filename string) ([]byte, error) {
-		str, ok := files[filename]
-		if !ok {
-			return []byte(nil), fmt.Errorf("no file found: %s", filename)
-		}
-		return []byte(str), nil
-	}
-	glob := func(pattern string) ([]string, error) {
-		matches, ok := globMatches[pattern]
-		if !ok {
-			return []string(nil), fmt.Errorf("no file matched: %s", pattern)
-		}
-		return matches, nil
-	}
-	abs := func(path string) (string, error) {
-		a, ok := absPaths[path]
-		if !ok {
-			return "", fmt.Errorf("abs: unexpected path: %s", path)
-		}
-		return a, nil
-	}
-	app := &app{
-		readFile:          readFile,
-		glob:              glob,
-		abs:               abs,
-		fileExistsAt:      fileExistsAt,
-		directoryExistsAt: directoryExistsAt,
-		kubeContext:       "default",
-		logger:            helmexec.NewLogger(os.Stderr, "debug"),
-	}
-	noop := func(st *state.HelmState, helm helmexec.Interface) []error {
-		return []error{}
-	}
-
-	testcases := []struct {
-		name      string
-		expectErr bool
-	}{
-		{name: "prometheus", expectErr: false},
-		{name: "zipkin", expectErr: false},
-		{name: "grafana", expectErr: false},
-		{name: "elasticsearch", expectErr: true},
-	}
-
-	for _, testcase := range testcases {
-		err := app.FindAndIterateOverDesiredStates(
-			"helmfile.yaml", noop, "", []string{fmt.Sprintf("name=%s", testcase.name)}, "default",
-		)
-		if testcase.expectErr && err == nil {
-			t.Errorf("error expected but not happened for name=%s", testcase.name)
-		} else if !testcase.expectErr && err != nil {
-			t.Errorf("unexpected error for name=%s: %v", testcase.name, err)
-		}
-	}
-}
-
-// See https://github.com/roboll/helmfile/issues/320
-func TestFindAndIterateOverDesiredStates_UndefinedEnv(t *testing.T) {
-	absPaths := map[string]string{
-		".": "/path/to",
-		"/path/to/helmfile.d": "/path/to/helmfile.d",
-	}
-	dirs := map[string]bool{
-		"helmfile.d": true,
-	}
-	files := map[string]string{
-		"helmfile.yaml": `
-environments:
-  prod:
-
-helmfiles:
-- helmfile.d/a*.yaml
-`,
-		"/path/to/helmfile.d/a1.yaml": `
-environments:
-  prod:
-
-releases:
-- name: zipkin
-  chart: stable/zipkin
-`,
-	}
-	globMatches := map[string][]string{
-		"/path/to/helmfile.d/a*.yaml": []string{"/path/to/helmfile.d/a1.yaml"},
-	}
-	fileExistsAt := func(path string) bool {
-		_, ok := files[path]
-		return ok
-	}
-	directoryExistsAt := func(path string) bool {
-		_, ok := dirs[path]
-		return ok
-	}
-	readFile := func(filename string) ([]byte, error) {
-		str, ok := files[filename]
-		if !ok {
-			return []byte(nil), fmt.Errorf("no file found: %s", filename)
-		}
-		return []byte(str), nil
-	}
-	glob := func(pattern string) ([]string, error) {
-		matches, ok := globMatches[pattern]
-		if !ok {
-			return []string(nil), fmt.Errorf("no file matched: %s", pattern)
-		}
-		return matches, nil
-	}
-	abs := func(path string) (string, error) {
-		a, ok := absPaths[path]
-		if !ok {
-			return "", fmt.Errorf("abs: unexpected path: %s", path)
-		}
-		return a, nil
-	}
-	app := &app{
-		readFile:          readFile,
-		glob:              glob,
-		abs:               abs,
-		fileExistsAt:      fileExistsAt,
-		directoryExistsAt: directoryExistsAt,
-		kubeContext:       "default",
-		logger:            helmexec.NewLogger(os.Stderr, "debug"),
-	}
-	noop := func(st *state.HelmState, helm helmexec.Interface) []error {
-		return []error{}
-	}
-
-	testcases := []struct {
-		name      string
-		expectErr bool
-	}{
-		{name: "undefined_env", expectErr: true},
-		{name: "default", expectErr: false},
-		{name: "prod", expectErr: false},
-	}
-
-	for _, testcase := range testcases {
-		err := app.FindAndIterateOverDesiredStates(
-			"helmfile.yaml", noop, "", []string{}, testcase.name,
-		)
-		if testcase.expectErr && err == nil {
-			t.Errorf("error expected but not happened for environment=%s", testcase.name)
-		} else if !testcase.expectErr && err != nil {
-			t.Errorf("unexpected error for environment=%s: %v", testcase.name, err)
-		}
-	}
-}
-
-// See https://github.com/roboll/helmfile/issues/322
-func TestFindAndIterateOverDesiredStates_Selectors(t *testing.T) {
-	absPaths := map[string]string{
-		".": "/path/to",
-		"/path/to/helmfile.d": "/path/to/helmfile.d",
-	}
-	dirs := map[string]bool{
-		"helmfile.d": true,
-	}
-	files := map[string]string{
-		"helmfile.yaml": `
-helmfiles:
-- helmfile.d/a*.yaml
-- helmfile.d/b*.yaml
-`,
-		"/path/to/helmfile.d/a1.yaml": `
-releases:
-- name: zipkin
-  chart: stable/zipkin
-`,
-		"/path/to/helmfile.d/a2.yaml": `
-releases:
-- name: prometheus
-  chart: stable/prometheus
-`,
-		"/path/to/helmfile.d/b.yaml": `
-releases:
-- name: grafana
-  chart: stable/grafana
-`,
-	}
-	globMatches := map[string][]string{
-		"/path/to/helmfile.d/a*.yaml": []string{"/path/to/helmfile.d/a1.yaml", "/path/to/helmfile.d/a2.yaml"},
-		"/path/to/helmfile.d/b*.yaml": []string{"/path/to/helmfile.d/b.yaml"},
-	}
-	fileExistsAt := func(path string) bool {
-		_, ok := files[path]
-		return ok
-	}
-	directoryExistsAt := func(path string) bool {
-		_, ok := dirs[path]
-		return ok
-	}
-	readFile := func(filename string) ([]byte, error) {
-		str, ok := files[filename]
-		if !ok {
-			return []byte(nil), fmt.Errorf("no file found: %s", filename)
-		}
-		return []byte(str), nil
-	}
-	glob := func(pattern string) ([]string, error) {
-		matches, ok := globMatches[pattern]
-		if !ok {
-			return []string(nil), fmt.Errorf("no file matched: %s", pattern)
-		}
-		return matches, nil
-	}
-	abs := func(path string) (string, error) {
-		a, ok := absPaths[path]
-		if !ok {
-			return "", fmt.Errorf("abs: unexpected path: %s", path)
-		}
-		return a, nil
-	}
-	app := &app{
-		readFile:          readFile,
-		glob:              glob,
-		abs:               abs,
-		fileExistsAt:      fileExistsAt,
-		directoryExistsAt: directoryExistsAt,
-		kubeContext:       "default",
-		logger:            helmexec.NewLogger(os.Stderr, "debug"),
-	}
-	noop := func(st *state.HelmState, helm helmexec.Interface) []error {
-		return []error{}
-	}
-
-	testcases := []struct {
-		label     string
-		expectErr bool
-		errMsg    string
-	}{
-		{label: "name=prometheus", expectErr: false},
-		{label: "name=", expectErr: true, errMsg: "Malformed label: name=. Expected label in form k=v or k!=v"},
-		{label: "name!=", expectErr: true, errMsg: "Malformed label: name!=. Expected label in form k=v or k!=v"},
-		{label: "name", expectErr: true, errMsg: "Malformed label: name. Expected label in form k=v or k!=v"},
-	}
-
-	for _, testcase := range testcases {
-		err := app.FindAndIterateOverDesiredStates(
-			"helmfile.yaml", noop, "", []string{testcase.label}, "default",
-		)
-		if testcase.expectErr {
-			if err == nil {
-				t.Errorf("error expected but not happened for name=%s", testcase.label)
-			} else if err.Error() != testcase.errMsg {
-				t.Errorf("unexpected error message: expected=\"%s\", actual=\"%s\"", testcase.errMsg, err.Error())
-			}
-		} else if !testcase.expectErr && err != nil {
-			t.Errorf("unexpected error for name=%s: %v", testcase.label, err)
-		}
-	}
-}
-
-// See https://github.com/roboll/helmfile/issues/312
-func TestFindAndIterateOverDesiredStates_ReverseOrder(t *testing.T) {
-	absPaths := map[string]string{
-		".": "/path/to",
-		"/path/to/helmfile.d": "/path/to/helmfile.d",
-	}
-	dirs := map[string]bool{
-		"helmfile.d": true,
-	}
-	files := map[string]string{
-		"helmfile.yaml": `
-helmfiles:
-- helmfile.d/a*.yaml
-- helmfile.d/b*.yaml
-`,
-		"/path/to/helmfile.d/a1.yaml": `
-releases:
-- name: zipkin
-  chart: stable/zipkin
-`,
-		"/path/to/helmfile.d/a2.yaml": `
-releases:
-- name: prometheus
-  chart: stable/prometheus
-- name: elasticsearch
-  chart: stable/elasticsearch
-`,
-		"/path/to/helmfile.d/b.yaml": `
-releases:
-- name: grafana
-  chart: stable/grafana
-`,
-	}
-	globMatches := map[string][]string{
-		"/path/to/helmfile.d/a*.yaml": []string{"/path/to/helmfile.d/a1.yaml", "/path/to/helmfile.d/a2.yaml"},
-		"/path/to/helmfile.d/b*.yaml": []string{"/path/to/helmfile.d/b.yaml"},
-	}
-	fileExistsAt := func(path string) bool {
-		_, ok := files[path]
-		return ok
-	}
-	directoryExistsAt := func(path string) bool {
-		_, ok := dirs[path]
-		return ok
-	}
-	readFile := func(filename string) ([]byte, error) {
-		str, ok := files[filename]
-		if !ok {
-			return []byte(nil), fmt.Errorf("no file found: %s", filename)
-		}
-		return []byte(str), nil
-	}
-	glob := func(pattern string) ([]string, error) {
-		matches, ok := globMatches[pattern]
-		if !ok {
-			return []string(nil), fmt.Errorf("no file matched: %s", pattern)
-		}
-		return matches, nil
-	}
-	abs := func(path string) (string, error) {
-		a, ok := absPaths[path]
-		if !ok {
-			return "", fmt.Errorf("abs: unexpected path: %s", path)
-		}
-		return a, nil
-	}
-
-	expected := []string{"grafana", "elasticsearch", "prometheus", "zipkin"}
-
-	testcases := []struct {
-		reverse  bool
-		expected []string
-	}{
-		{reverse: false, expected: []string{"zipkin", "prometheus", "elasticsearch", "grafana"}},
-		{reverse: true, expected: []string{"grafana", "elasticsearch", "prometheus", "zipkin"}},
-	}
-	for _, testcase := range testcases {
-		actual := []string{}
-
-		collectReleases := func(st *state.HelmState, helm helmexec.Interface) []error {
-			for _, r := range st.Releases {
-				actual = append(actual, r.Name)
-			}
-			return []error{}
-		}
-
-		app := &app{
-			readFile:          readFile,
-			glob:              glob,
-			abs:               abs,
-			fileExistsAt:      fileExistsAt,
-			directoryExistsAt: directoryExistsAt,
-			kubeContext:       "default",
-			logger:            helmexec.NewLogger(os.Stderr, "debug"),
-			reverse:           testcase.reverse,
-		}
-		err := app.FindAndIterateOverDesiredStates(
-			"helmfile.yaml", collectReleases, "", []string{}, "default",
-		)
-		if err != nil {
-			t.Errorf("unexpected error: %v", err)
-		}
-		if !reflect.DeepEqual(testcase.expected, actual) {
-			t.Errorf("releases did not match: expected=%v actual=%v", expected, actual)
-		}
-	}
-}

cmd/cmd.go

@@ -0,0 +1,100 @@
+package cmd
+
+import (
+	"fmt"
+	"github.com/roboll/helmfile/helmexec"
+	"github.com/roboll/helmfile/pkg/app"
+	"github.com/roboll/helmfile/state"
+	"github.com/urfave/cli"
+	"go.uber.org/zap"
+	"os/exec"
+	"strings"
+	"syscall"
+)
+
+func VisitAllDesiredStates(c *cli.Context, converge func(*state.HelmState, helmexec.Interface, app.Context) (bool, []error)) error {
+	a, fileOrDir, err := InitAppEntry(c, false)
+	if err != nil {
+		return err
+	}
+
+	ctx := app.NewContext()
+
+	convergeWithHelmBinary := func(st *state.HelmState, helm helmexec.Interface) (bool, []error) {
+		if c.GlobalString("helm-binary") != "" {
+			helm.SetHelmBinary(c.GlobalString("helm-binary"))
+		}
+		return converge(st, helm, ctx)
+	}
+
+	err = a.VisitDesiredStates(fileOrDir, convergeWithHelmBinary)
+
+	return toCliError(err)
+}
+
+func InitAppEntry(c *cli.Context, reverse bool) (*app.App, string, error) {
+	if c.NArg() > 0 {
+		cli.ShowAppHelp(c)
+		return nil, "", fmt.Errorf("err: extraneous arguments: %s", strings.Join(c.Args(), ", "))
+	}
+
+	fileOrDir := c.GlobalString("file")
+	kubeContext := c.GlobalString("kube-context")
+	namespace := c.GlobalString("namespace")
+	selectors := c.GlobalStringSlice("selector")
+	logger := c.App.Metadata["logger"].(*zap.SugaredLogger)
+
+	env := c.GlobalString("environment")
+	if env == "" {
+		env = state.DefaultEnv
+	}
+
+	app := app.Init(&app.App{
+		KubeContext: kubeContext,
+		Logger:      logger,
+		Reverse:     reverse,
+		Env:         env,
+		Namespace:   namespace,
+		Selectors:   selectors,
+	})
+
+	return app, fileOrDir, nil
+}
+
+func FindAndIterateOverDesiredStatesUsingFlagsWithReverse(c *cli.Context, reverse bool, converge func(*state.HelmState, helmexec.Interface, app.Context) []error) error {
+	a, fileOrDir, err := InitAppEntry(c, reverse)
+	if err != nil {
+		return err
+	}
+
+	ctx := app.NewContext()
+
+	convergeWithHelmBinary := func(st *state.HelmState, helm helmexec.Interface) []error {
+		if c.GlobalString("helm-binary") != "" {
+			helm.SetHelmBinary(c.GlobalString("helm-binary"))
+		}
+		return converge(st, helm, ctx)
+	}
+
+	err = a.VisitDesiredStatesWithReleasesFiltered(fileOrDir, convergeWithHelmBinary)
+
+	return toCliError(err)
+}
+
+func toCliError(err error) error {
+	if err != nil {
+		switch e := err.(type) {
+		case *app.NoMatchingHelmfileError:
+			return cli.NewExitError(e.Error(), 2)
+		case *exec.ExitError:
+			// Propagate any non-zero exit status from the external command like `helm` that is failed under the hood
+			status := e.Sys().(syscall.WaitStatus)
+			return cli.NewExitError(e.Error(), status.ExitStatus())
+		case *state.DiffError:
+			return cli.NewExitError(e.Error(), e.Code)
+		default:
+			return cli.NewExitError(e.Error(), 1)
+		}
+	}
+	return err
+}

cmd/deps.go

@@ -0,0 +1,37 @@
+package cmd
+
+import (
+	"github.com/roboll/helmfile/args"
+	"github.com/roboll/helmfile/helmexec"
+	"github.com/roboll/helmfile/pkg/app"
+	"github.com/roboll/helmfile/state"
+	"github.com/urfave/cli"
+)
+
+func Deps(a *app.App) cli.Command {
+	return cli.Command{
+		Name:  "deps",
+		Usage: "update charts based on the contents of requirements.yaml",
+		Flags: []cli.Flag{
+			cli.StringFlag{
+				Name:  "args",
+				Value: "",
+				Usage: "pass args to helm exec",
+			},
+		},
+		Action: func(c *cli.Context) error {
+			return VisitAllDesiredStates(c, func(state *state.HelmState, helm helmexec.Interface, ctx app.Context) (bool, []error) {
+				args := args.GetArgs(c.String("args"), state)
+				if len(args) > 0 {
+					helm.SetExtraArgs(args...)
+				}
+
+				errs := state.UpdateDeps(helm)
+
+				ok := len(errs) == 0
+
+				return ok, errs
+			})
+		},
+	}
+}

docs/writing-helmfile.md

@@ -2,11 +2,100 @@
 
 This guide covers the Helmfile’s considered patterns for writing advanced helmfiles. It focuses on how helmfile should be structured and executed.
 
+## Missing keys and Default values
+
+helmfile tries its best to inform users for noticing potential mistakes.
+
+One example of how helmfile achieves it is that, `helmfile` fails when you tried to access missing keys in environment values.
+
+That is, the following example let `helmfile` fail when you have no `eventApi.replicas` defined in environment values.
+
+```
+{{ .Environment.Values.eventApi.replicas | default 1 }}
+```
+
+In case it isn't a mistake and you do want to allow missing keys, use the `getOrNil` template function:
+
+```
+{{ .Environment.Values | getOrNil "eventApi.replicas" }}
+```
+
+This result in printing `<no value` in your template, that may or may not result in a failure.
+
+If you want a kind of default values that is used when a missing key was referenced, use `default` like:
+
+```
+{{ .Environment.Values | getOrNil "eventApi.replicas" | default 1 }}
+```
+
+Now, you get `1` when there is no `eventApi.replicas` defined in environment values.
+
+## Release Template / Conventional Directory Structure
+
+Introducing helmfile into a large-scale project that involes dozens of releases often results in a lot of repetitions in `helmfile.yaml` files.
+
+The example below shows repetitions in `namespace`, `chart`, `values`, and `secrets`:
+
+```yaml
+releases:
+# *snip*
+- name: heapster
+  namespace: kube-system
+  chart: stable/heapster
+  version: 0.3.2
+  values:
+  - "./config/heapster/values.yaml"
+  - "./config/heapster/{{ .Environment.Name }}.yaml"
+  secrets:
+  - "./config/heapster/secrets.yaml"
+  - "./config/heapster/{{ .Environment.Name }}-secrets.yaml"
+
+- name: kubernetes-dashboard
+  namespace: kube-system
+  chart: stable/kubernetes-dashboard
+  version: 0.10.0
+  values:
+  - "./config/kubernetes-dashboard/values.yaml"
+  - "./config/kubernetes-dashboard/{{ .Environment.Name }}.yaml"
+  values:
+  - "./config/kubernetes-dashboard/secrets.yaml"
+  - "./config/kubernetes-dashboard/{{ .Environment.Name }}-secrets.yaml"
+```
+
+This is where Helmfile's advanced feature called Release Template comes handy.
+
+It allows you to abstract away the repetitions in releases into a template, which is then included and executed by using YAML anchor/alias:
+
+```yaml
+templates:
+  default: &default
+    chart: stable/{{`{{ .Release.Name }}`}}
+    namespace: kube-system
+    # This prevents helmfile exiting when it encounters a missing file
+    # Valid values are "Error", "Warn", "Info", "Debug". The default is "Error"
+    # Use "Debug" to make missing files errors invisible at the default log level(--log-level=INFO)
+    missingFileHandler: Warn
+    values:
+    - config/{{`{{ .Release.Name }}`}}/values.yaml
+    - config/{{`{{ .Release.Name }}`}}/{{`{{ .Environment.Name }}`}}.yaml
+    secrets:
+    - config/{{`{{ .Release.Name }}`}}/secrets.yaml
+    - config/{{`{{ .Release.Name }}`}}/{{`{{ .Environment.Name }}`}}-secrets.yaml
+
+releases:
+- name: heapster
+  <<: *default
+- name: kubernetes-dashboard
+  <<: *default
+```
+
+See the [issue 428](https://github.com/roboll/helmfile/issues/428) for more context on how this is supposed to work.
+
 ## Layering
 
 You may occasionally end up with many helmfiles that shares common parts like which repositories to use, and whichi release to be bundled by default.
 
-Use Layering to extract te common parts into a dedicated *library helmfile*s, so that each helmfile becomes DRY.
+Use Layering to extract the common parts into a dedicated *library helmfile*s, so that each helmfile becomes DRY.
 
 Let's assume that your `helmfile.yaml` looks like:
 

event/bus.go

@@ -0,0 +1,102 @@
+package event
+
+import (
+	"fmt"
+	"github.com/roboll/helmfile/environment"
+	"github.com/roboll/helmfile/helmexec"
+	"github.com/roboll/helmfile/tmpl"
+	"go.uber.org/zap"
+	"os"
+)
+
+type Hook struct {
+	Name    string   `yaml:"name"`
+	Events  []string `yaml:"events"`
+	Command string   `yaml:"command"`
+	Args    []string `yaml:"args"`
+}
+
+type event struct {
+	Name string
+}
+
+type Bus struct {
+	Runner helmexec.Runner
+	Hooks  []Hook
+
+	BasePath      string
+	StateFilePath string
+	Namespace     string
+
+	Env environment.Environment
+
+	ReadFile func(string) ([]byte, error)
+	Logger   *zap.SugaredLogger
+}
+
+func (bus *Bus) Trigger(evt string, context map[string]interface{}) (bool, error) {
+	if bus.Runner == nil {
+		bus.Runner = helmexec.ShellRunner{
+			Dir: bus.BasePath,
+		}
+	}
+
+	executed := false
+
+	for _, hook := range bus.Hooks {
+		contained := false
+		for _, e := range hook.Events {
+			contained = contained || e == evt
+		}
+		if !contained {
+			continue
+		}
+
+		var err error
+
+		name := hook.Name
+		if name == "" {
+			name = hook.Command
+		}
+
+		fmt.Fprintf(os.Stderr, "%s: basePath=%s\n", bus.StateFilePath, bus.BasePath)
+
+		data := map[string]interface{}{
+			"Environment": bus.Env,
+			"Namespace":   bus.Namespace,
+			"Event": event{
+				Name: evt,
+			},
+		}
+		for k, v := range context {
+			data[k] = v
+		}
+		render := tmpl.NewTextRenderer(bus.ReadFile, bus.BasePath, data)
+
+		bus.Logger.Debugf("hook[%s]: triggered by event \"%s\"\n", name, evt)
+
+		command, err := render.RenderTemplateText(hook.Command)
+		if err != nil {
+			return false, fmt.Errorf("hook[%s]: %v", name, err)
+		}
+
+		args := make([]string, len(hook.Args))
+		for i, raw := range hook.Args {
+			args[i], err = render.RenderTemplateText(raw)
+			if err != nil {
+				return false, fmt.Errorf("hook[%s]: %v", name, err)
+			}
+		}
+
+		bytes, err := bus.Runner.Execute(command, args)
+		bus.Logger.Debugf("hook[%s]: %s\n", name, string(bytes))
+
+		if err != nil {
+			return false, fmt.Errorf("hook[%s]: command `%s` failed: %v", name, command, err)
+		}
+
+		executed = true
+	}
+
+	return executed, nil
+}

event/bus_test.go

@@ -0,0 +1,113 @@
+package event
+
+import (
+	"fmt"
+	"github.com/roboll/helmfile/environment"
+	"github.com/roboll/helmfile/helmexec"
+	"os"
+	"testing"
+)
+
+var logger = helmexec.NewLogger(os.Stdout, "warn")
+
+type runner struct {
+}
+
+func (r *runner) Execute(cmd string, args []string) ([]byte, error) {
+	if cmd == "ng" {
+		return nil, fmt.Errorf("cmd failed due to invalid cmd: %s", cmd)
+	}
+	for _, a := range args {
+		if a == "ng" {
+			return nil, fmt.Errorf("cmd failed due to invalid arg: %s", a)
+		}
+	}
+	return []byte(""), nil
+}
+
+func TestTrigger(t *testing.T) {
+	cases := []struct {
+		name           string
+		hook           *Hook
+		triggeredEvt   string
+		expectedResult bool
+		expectedErr    string
+	}{
+		{
+			"okhook1",
+			&Hook{"okhook1", []string{"foo"}, "ok", []string{}},
+			"foo",
+			true,
+			"",
+		},
+		{
+			"missinghook1",
+			&Hook{"okhook1", []string{"foo"}, "ok", []string{}},
+			"bar",
+			false,
+			"",
+		},
+		{
+			"nohook1",
+			nil,
+			"bar",
+			false,
+			"",
+		},
+		{
+			"nghook1",
+			&Hook{"nghook1", []string{"foo"}, "ng", []string{}},
+			"foo",
+			false,
+			"hook[nghook1]: command `ng` failed: cmd failed due to invalid cmd: ng",
+		},
+		{
+			"nghook2",
+			&Hook{"nghook2", []string{"foo"}, "ok", []string{"ng"}},
+			"foo",
+			false,
+			"hook[nghook2]: command `ok` failed: cmd failed due to invalid arg: ng",
+		},
+	}
+	readFile := func(filename string) ([]byte, error) {
+		return nil, fmt.Errorf("unexpected call to readFile: %s", filename)
+	}
+	for _, c := range cases {
+		hooks := []Hook{}
+		if c.hook != nil {
+			hooks = append(hooks, *c.hook)
+		}
+		bus := &Bus{
+			Hooks:         hooks,
+			StateFilePath: "path/to/helmfile.yaml",
+			BasePath:      "path/to",
+			Namespace:     "myns",
+			Env:           environment.Environment{Name: "prod"},
+			Logger:        logger,
+			ReadFile:      readFile,
+		}
+
+		bus.Runner = &runner{}
+		data := map[string]interface{}{
+			"Release":         "myrel",
+			"HelmfileCommand": "mycmd",
+		}
+		ok, err := bus.Trigger(c.triggeredEvt, data)
+
+		if ok != c.expectedResult {
+			t.Errorf("unexpected result for case \"%s\": expected=%v, actual=%v", c.name, c.expectedResult, ok)
+		}
+
+		if c.expectedErr != "" {
+			if err == nil {
+				t.Error("error expected, but not occurred")
+			} else if err.Error() != c.expectedErr {
+				t.Errorf("unexpected error for case \"%s\": expected=%s, actual=%v", c.name, c.expectedErr, err)
+			}
+		} else {
+			if err != nil {
+				t.Errorf("unexpected error for case \"%s\": %v", c.name, err)
+			}
+		}
+	}
+}

hack/semtag

@@ -0,0 +1,623 @@
+#!/usr/bin/env bash
+
+PROG=semtag
+PROG_VERSION="v0.1.0"
+
+SEMVER_REGEX="^v?(0|[1-9][0-9]*)\.(0|[1-9][0-9]*)\.(0|[1-9][0-9]*)(\-[0-9A-Za-z-]+(\.[0-9A-Za-z-]+)*)?(\+[0-9A-Za-z-]+(\.[0-9A-Za-z-]+)*)?$"
+IDENTIFIER_REGEX="^\-([0-9A-Za-z-]+)\.([0-9A-Za-z-]+)*$"
+
+# Global variables
+FIRST_VERSION="v0.0.0"
+finalversion=$FIRST_VERSION
+lastversion=$FIRST_VERSION
+hasversiontag="false"
+scope="patch"
+displayonly="false"
+forcetag="false"
+forcedversion=
+versionname=
+identifier=
+
+HELP="\
+Usage:
+  $PROG
+  $PROG getlast
+  $PROG getfinal
+  $PROG (final|alpha|beta|candidate) [-s <scope> (major|minor|patch|auto) | -o]
+  $PROG --help
+  $PROG --version
+Options:
+  -s         The scope that must be increased, can be major, minor or patch.
+               The resulting version will match X.Y.Z(-PRERELEASE)(+BUILD)
+               where X, Y and Z are positive integers, PRERELEASE is an optionnal
+               string composed of alphanumeric characters describing if the build is
+               a release candidate, alpha or beta version, with a number.
+               BUILD is also an optional string composed of alphanumeric
+               characters and hyphens.
+               Setting the scope as 'auto', the script will chose the scope between
+               'minor' and 'patch', depending on the amount of lines added (<10% will
+               choose patch).
+  -v         Specifies manually the version to be tagged, must be a valid semantic version
+               in the format X.Y.Z where X, Y and Z are positive integers.
+  -o         Output the version only, shows the bumped version, but doesn't tag.
+  -f         Forces to tag, even if there are unstaged or uncommited changes.
+Commands:
+  --help     Print this help message.
+  --version  Prints the program's version.
+  get        Returns both current final version and last tagged version.
+  getlast    Returns the latest tagged version.
+  getfinal   Returns the latest tagged final version.
+  getcurrent Returns the current version, based on the latest one, if there are uncommited or
+               unstaged changes, they will be reflected in the version, adding the number of
+               pending commits, current branch and commit hash.
+  final      Tags the current build as a final version, this only can be done on the master branch.
+  candidate  Tags the current build as a release candidate, the tag will contain all
+               the commits from the last final version.
+  alpha      Tags the current build as an alpha version, the tag will contain all
+               the commits from the last final version.
+  beta       Tags the current build as a beta version, the tag will contain all
+               the commits from the last final version."
+
+# Commands and options
+ACTION="getlast"
+ACTION="$1"
+shift
+
+# We get the parameters
+while getopts "v:s:of" opt; do
+  case $opt in
+    v)
+      forcedversion="$OPTARG"
+      ;;
+    s)
+      scope="$OPTARG"
+      ;;
+    o)
+      displayonly="true"
+      ;;
+    f)
+      forcetag="true"
+      ;;
+    \?)
+      echo "Invalid option: -$OPTARG" >&2
+      exit 1
+      ;;
+    :)
+      echo "Option -$OPTARG requires an argument." >&2
+      exit 1
+      ;;
+  esac
+done
+
+# Gets a string with the version and returns an array of maximum size of 5 with all the parts of the sematinc version
+# $1 The string containing the version in semantic format
+# $2 The variable to store the result array:
+#      position 0: major number
+#      position 1: minor number
+#      position 2: patch number
+#      position 3: identifier (or prerelease identifier)
+#      position 4: build info
+function explode_version {
+  local __version=$1
+  local __result=$2
+  if [[ $__version =~ $SEMVER_REGEX ]] ; then
+    local __major=${BASH_REMATCH[1]}
+    local __minor=${BASH_REMATCH[2]}
+    local __patch=${BASH_REMATCH[3]}
+    local __prere=${BASH_REMATCH[4]}
+    local __build=${BASH_REMATCH[5]}
+    eval "$__result=(\"$__major\" \"$__minor\" \"$__patch\" \"$__prere\" \"$__build\")"
+  else
+    eval "$__result="
+  fi
+}
+
+# Compare two versions and returns -1, 0 or 1
+# $1 The first version to compare
+# $2 The second version to compare
+# $3 The variable where to store the result
+function compare_versions {
+  local __first
+  local __second
+  explode_version $1 __first
+  explode_version $2 __second
+  local lv=$3
+
+  # Compares MAJOR, MINOR and PATCH
+  for i in 0 1 2; do
+    local __numberfirst=${__first[$i]}
+    local __numbersecond=${__second[$i]}
+    case $(($__numberfirst - $__numbersecond)) in
+      0)
+        ;;
+      -[0-9]*)
+        eval "$lv=-1"
+        return 0
+        ;;
+      [0-9]*)
+        eval "$lv=1"
+        return 0
+        ;;
+    esac
+  done
+
+  # Identifiers should compare with the ASCII order.
+  local __identifierfirst=${__first[3]}
+  local __identifiersecond=${__second[3]}
+  if [[ -n "$__identifierfirst" ]] && [[ -n "$__identifiersecond" ]]; then
+    if [[ "$__identifierfirst" > "$__identifiersecond" ]]; then
+      eval "$lv=1"
+      return 0
+    elif [[ "$__identifierfirst" < "$__identifiersecond" ]]; then
+      eval "$lv=-1"
+      return 0
+    fi
+  elif [[ -z "$__identifierfirst" ]] && [[ -n "$__identifiersecond" ]]; then
+    eval "$lv=1"
+    return 0
+  elif [[ -n "$__identifierfirst" ]] && [[ -z "$__identifiersecond" ]]; then
+    eval "$lv=-1"
+    return 0
+  fi
+
+  eval "$lv=0"
+}
+
+# Returns the last version of two
+# $1 The first version to compare
+# $2 The second version to compare
+# $3 The variable where to store the last one
+function get_latest_of_two {
+  local __first=$1
+  local __second=$2
+  local __result
+  local __latest=$3
+  compare_versions $__first $__second __result
+  case $__result in
+    0)
+      eval "$__latest=$__second"
+      ;;
+    -1)
+      eval "$__latest=$__second"
+      ;;
+    1)
+      eval "$__latest=$__first"
+      ;;
+  esac
+}
+
+# Assigns a 2 size array with the identifier, having the identifier at pos 0, and the number in pos 1
+# $1 The identifier in the format -id.#
+# $2 The vferiable where to store the 2 size array
+function explode_identifier {
+  local __identifier=$1
+  local __result=$2
+  if [[ $__identifier =~ $IDENTIFIER_REGEX ]] ; then
+    local __id=${BASH_REMATCH[1]}
+    local __number=${BASH_REMATCH[2]}
+    if [[ -z "$__number" ]]; then
+      __number=1
+    fi
+    eval "$__result=(\"$__id\" \"$__number\")"
+  else
+    eval "$__result="
+  fi
+}
+
+# Gets a list of tags and assigns the base and latest versions
+# Receives an array with the tags containing the versions
+# Assigns to the global variables finalversion and lastversion the final version and the latest version
+function get_latest {
+  local __taglist=("$@")
+  local __tagsnumber=${#__taglist[@]}
+  local __current
+  case $__tagsnumber in
+    0)
+      finalversion=$FIRST_VERSION
+      lastversion=$FIRST_VERSION
+      ;;
+    1)
+      __current=${__taglist[0]}
+      explode_version $__current ver
+      if [ -n "$ver" ]; then
+        if [ -n "${ver[3]}" ]; then
+          finalversion=$FIRST_VERSION
+        else
+          finalversion=$__current
+        fi
+        lastversion=$__current
+      else
+        finalversion=$FIRST_VERSION
+        lastversion=$FIRST_VERSION
+      fi
+      ;;
+    *)
+      local __lastpos=$(($__tagsnumber-1))
+      for i in $(seq 0 $__lastpos)
+      do
+        __current=${__taglist[i]}
+        explode_version ${__taglist[i]} ver
+        if [ -n "$ver" ]; then
+          if [ -z "${ver[3]}" ]; then
+            get_latest_of_two $finalversion $__current finalversion
+            get_latest_of_two $lastversion $finalversion lastversion
+          else
+            get_latest_of_two $lastversion $__current lastversion
+          fi
+        fi
+      done
+      ;;
+  esac
+
+  if git rev-parse -q --verify "refs/tags/$lastversion" >/dev/null; then
+    hasversiontag="true"
+  else
+    hasversiontag="false"
+  fi
+}
+
+# Gets the next version given the provided scope
+# $1 The version that is going to be bumped
+# $2 The scope to bump
+# $3 The variable where to stoer the result
+function get_next_version {
+  local __exploded
+  local __fromversion=$1
+  local __scope=$2
+  local __result=$3
+  explode_version $__fromversion __exploded
+  case $__scope in
+    major)
+      __exploded[0]=$((${__exploded[0]}+1))
+      __exploded[1]=0
+      __exploded[2]=0
+    ;;
+    minor)
+      __exploded[1]=$((${__exploded[1]}+1))
+      __exploded[2]=0
+    ;;
+    patch)
+      __exploded[2]=$((${__exploded[2]}+1))
+    ;;
+  esac
+
+  eval "$__result=v${__exploded[0]}.${__exploded[1]}.${__exploded[2]}"
+}
+
+function bump_version {
+  ## First we try to get the next version based on the existing last one
+  if [ "$scope" == "auto" ]; then
+    get_scope_auto scope
+  fi
+
+  local __candidatefromlast=$FIRST_VERSION
+  local __explodedlast
+  explode_version $lastversion __explodedlast
+  if [[ -n "${__explodedlast[3]}" ]]; then
+    # Last version is not final
+    local __idlast
+    explode_identifier ${__explodedlast[3]} __idlast
+    
+    # We get the last, given the desired id based on the scope
+    __candidatefromlast="v${__explodedlast[0]}.${__explodedlast[1]}.${__explodedlast[2]}"
+    if [[ -n "$identifier" ]]; then
+      local __nextid="$identifier.1"
+      if [ "$identifier" == "${__idlast[0]}" ]; then
+        # We target the same identifier as the last so we increase one
+        __nextid="$identifier.$(( ${__idlast[1]}+1 ))"
+        __candidatefromlast="$__candidatefromlast-$__nextid"
+      else
+        # Different identifiers, we make sure we are assigning a higher identifier, if not, we increase the version
+        __candidatefromlast="$__candidatefromlast-$__nextid"
+        local __comparedwithlast
+        compare_versions $__candidatefromlast $lastversion __comparedwithlast
+        if [ "$__comparedwithlast" == -1 ]; then
+          get_next_version $__candidatefromlast $scope __candidatefromlast
+          __candidatefromlast="$__candidatefromlast-$__nextid"
+        fi
+      fi
+    fi
+  fi
+
+  # Then we try to get the version based on the latest final one
+  local __candidatefromfinal=$FIRST_VERSION
+  get_next_version $finalversion $scope __candidatefromfinal
+  if [[ -n "$identifier" ]]; then
+    __candidatefromfinal="$__candidatefromfinal-$identifier.1"
+  fi
+
+  # Finally we compare both candidates
+  local __resultversion
+  local __result
+  compare_versions $__candidatefromlast $__candidatefromfinal __result
+  case $__result in
+    0)
+      __resultversion=$__candidatefromlast
+      ;;
+    -1)
+      __resultversion="$__candidatefromfinal"
+      ;;
+    1)
+      __resultversion=$__candidatefromlast
+      ;;
+  esac
+
+  eval "$1=$__resultversion"
+}
+
+function increase_version {
+  local __version=
+
+  if [ -z $forcedversion ]; then
+    bump_version __version
+  else
+    if [[ $forcedversion =~ $SEMVER_REGEX ]] ; then
+      compare_versions $forcedversion $lastversion __result
+      if [ $__result -le 0 ]; then
+        echo "Version can't be lower than last version: $lastversion"
+        exit 1
+      fi
+    else
+      echo "Non valid version to bump"
+      exit 1
+    fi
+    __version=$forcedversion
+  fi
+
+  if [ "$displayonly" == "true" ]; then
+    echo "$__version"
+  else
+    if [ "$forcetag" == "false" ]; then
+      check_git_dirty_status
+    fi
+    local __commitlist
+    if [ "$finalversion" == "$FIRST_VERSION" ] || [ "$hasversiontag" != "true" ]; then
+      __commitlist="$(git log --pretty=oneline | cat)"
+    else
+      __commitlist="$(git log --pretty=oneline $finalversion... | cat)"
+    fi
+
+    # If we are forcing a bump, we add bump to the commit list
+    if [[ -z $__commitlist && "$forcetag" == "true" ]]; then
+      __commitlist="bump"
+    fi
+
+    if [[ -z $__commitlist ]]; then
+      echo "No commits since the last final version, not bumping version"
+    else
+      if [[ -z $versionname ]]; then
+        versionname=$(date -u +"%Y-%m-%dT%H:%M:%SZ")
+      fi
+      local __message="$versionname
+$__commitlist"
+
+      # We check we have info on the user
+      local __username=$(git config user.name)
+      if [ -z "$__username" ]; then
+        __username=$(id -u -n)
+        git config user.name $__username
+      fi
+      local __useremail=$(git config user.email)
+      if [ -z "$__useremail" ]; then
+        __useremail=$(hostname)
+        git config user.email "$__username@$__useremail"
+      fi
+
+      git tag -a $__version -m "$__message" 
+
+      # If we have a remote, we push there
+      local __remote=${SEMTAG_REMOTE:-$(git remote)}
+      if [[ -n $__remote ]]; then
+        git push $__remote $__version > /dev/null
+        if [ $? -eq 0 ]; then
+          echo "$__version"
+        else
+          echo "Error pushing the tag $__version to $__remote"
+          exit 1
+        fi
+      else
+        echo "$__version"
+      fi
+    fi
+  fi
+}
+
+function check_git_dirty_status {
+  local __repostatus=
+  get_work_tree_status __repostatus
+
+  if [ "$__repostatus" == "uncommitted" ]; then
+    echo "ERROR: You have uncommitted changes"
+    git status --porcelain
+    exit 1
+  fi
+
+  if [ "$__repostatus" == "unstaged" ]; then
+    echo "ERROR: You have unstaged changes"
+    git status --porcelain
+    exit 1
+  fi
+}
+
+# Get the total amount of lines of code in the repo
+function get_total_lines {
+  local __empty_id="$(git hash-object -t tree /dev/null)"
+  local __changes="$(git diff --numstat $__empty_id | cat)"
+  local __added_deleted=$1
+  get_changed_lines "$__changes" $__added_deleted
+}
+
+# Get the total amount of lines of code since the provided tag
+function get_sincetag_lines {
+  local __sincetag=$1
+  local __changes="$(git diff --numstat $__sincetag | cat)"
+  local __added_deleted=$2
+  get_changed_lines "$__changes" $__added_deleted
+}
+
+function get_changed_lines {
+  local __changes_numstat=$1
+  local __result=$2
+  IFS=$'\n' read -rd '' -a __changes_array <<<"$__changes_numstat"
+  local __diff_regex="^([0-9]+)[[:space:]]+([0-9]+)[[:space:]]+.+$"
+
+  local __total_added=0
+  local __total_deleted=0
+  for i in "${__changes_array[@]}"
+  do
+    if [[ $i =~ $__diff_regex ]] ; then
+      local __added=${BASH_REMATCH[1]}
+      local __deleted=${BASH_REMATCH[2]}
+      __total_added=$(( $__total_added+$__added ))
+      __total_deleted=$(( $__total_deleted+$__deleted ))
+    fi
+  done
+  eval "$2=( $__total_added $__total_deleted )"
+}
+
+function get_scope_auto {
+  local __verbose=$2
+  local __total=0
+  local __since=0
+  local __scope=
+
+  get_total_lines __total
+  get_sincetag_lines $finalversion __since
+
+  local __percentage=0
+  if [ "$__total" != "0" ]; then
+    local __percentage=$(( 100*$__since/$__total ))
+    if [ $__percentage -gt "10" ]; then
+      __scope="minor"
+    else
+      __scope="patch"
+    fi
+  fi
+
+  eval "$1=$__scope"
+  if [[ -n "$__verbose" ]]; then
+    echo "[Auto Scope] Percentage of lines changed: $__percentage"
+    echo "[Auto Scope] : $__scope"
+  fi
+}
+
+function get_work_tree_status {
+  # Update the index
+  git update-index -q --ignore-submodules --refresh > /dev/null
+  eval "$1="
+
+  if ! git diff-files --quiet --ignore-submodules -- > /dev/null
+  then
+    eval "$1=unstaged"
+  fi
+
+  if ! git diff-index --cached --quiet HEAD --ignore-submodules -- > /dev/null
+  then
+    eval "$1=uncommitted"
+  fi
+}
+
+function get_current {
+  if [ "$hasversiontag" == "true" ]; then
+    local __commitcount="$(git rev-list $lastversion.. --count)"
+  else
+    local __commitcount="$(git rev-list --count HEAD)"
+  fi
+  local __status=
+  get_work_tree_status __status
+  
+  if [ "$__commitcount" == "0" ] && [ -z "$__status" ]; then
+    eval "$1=$lastversion"
+  else
+    local __buildinfo="$(git rev-parse --short HEAD)"
+    local __currentbranch="$(git rev-parse --abbrev-ref HEAD)"
+    if [ "$__currentbranch" != "master" ]; then
+      __buildinfo="$__currentbranch.$__buildinfo"
+    fi
+
+    local __suffix=
+    if [ "$__commitcount" != "0" ]; then
+      if [ -n "$__suffix" ]; then
+        __suffix="$__suffix."
+      fi
+      __suffix="$__suffix$__commitcount"
+    fi
+    if [ -n "$__status" ]; then
+      if [ -n "$__suffix" ]; then
+        __suffix="$__suffix."
+      fi
+      __suffix="$__suffix$__status"
+    fi
+
+    __suffix="$__suffix+$__buildinfo"
+    if [ "$lastversion" == "$finalversion" ]; then
+      scope="patch"
+      identifier=
+      local __bumped=
+      bump_version __bumped
+      eval "$1=$__bumped-dev.$__suffix"
+    else
+      eval "$1=$lastversion.$__suffix"
+    fi
+  fi
+}
+
+function init {
+  git fetch > /dev/null
+  TAGS="$(git tag)"
+  IFS=$'\n' read -rd '' -a TAG_ARRAY <<<"$TAGS"
+
+  get_latest ${TAG_ARRAY[@]}
+  currentbranch="$(git rev-parse --abbrev-ref HEAD)"
+}
+
+case $ACTION in
+  --help)
+    echo -e "$HELP"
+    ;;
+  --version)
+    echo -e "${PROG}: $PROG_VERSION"
+    ;;
+  final)
+    init
+    diff=$(git diff master | cat)
+    if [ "$forcetag" == "false" ]; then
+      if [ -n "$diff" ]; then
+        echo "ERROR: Branch must be updated with master for final versions"
+        exit 1
+      fi
+    fi
+    increase_version
+    ;;
+  alpha|beta)
+    init
+    identifier="$ACTION"
+    increase_version
+    ;;
+  candidate)
+    init
+    identifier="rc"
+    increase_version
+    ;;
+  getlast)
+    init
+    echo "$lastversion"
+    ;;
+  getfinal)
+    init
+    echo "$finalversion"
+    ;;
+  getcurrent)
+    init
+    get_current current
+    echo "$current"
+    ;;
+  get)
+    init
+    echo "Current final version: $finalversion"
+    echo "Last tagged version:   $lastversion"
+    ;;
+  *)
+    echo "'$ACTION' is not a valid command, see --help for available commands."
+    ;;
+esac

helmexec/exec.go

@@ -89,6 +89,13 @@ func (helm *execer) UpdateDeps(chart string) error {
 	return err
 }
 
+func (helm *execer) BuildDeps(chart string) error {
+	helm.logger.Infof("Building dependency %v", chart)
+	out, err := helm.exec("dependency", "build", chart)
+	helm.write(out)
+	return err
+}
+
 func (helm *execer) SyncRelease(name, chart string, flags ...string) error {
 	helm.logger.Infof("Upgrading %v", chart)
 	out, err := helm.exec(append([]string{"upgrade", "--install", "--reset-values", name, chart}, flags...)...)
@@ -103,6 +110,13 @@ func (helm *execer) ReleaseStatus(name string) error {
 	return err
 }
 
+func (helm *execer) List(filter string) (string, error) {
+	helm.logger.Infof("Listing releases matching %v", filter)
+	out, err := helm.exec(append([]string{"list", filter})...)
+	helm.write(out)
+	return string(out), err
+}
+
 func (helm *execer) DecryptSecret(name string) (string, error) {
 	// Prevents https://github.com/roboll/helmfile/issues/258
 	helm.decryptionMutex.Lock()
@@ -111,6 +125,9 @@ func (helm *execer) DecryptSecret(name string) (string, error) {
 	helm.logger.Infof("Decrypting secret %v", name)
 	out, err := helm.exec(append([]string{"secrets", "dec", name})...)
 	helm.write(out)
+	if err != nil {
+		return "", err
+	}
 
 	tmpFile, err := ioutil.TempFile("", "secret")
 	if err != nil {

helmexec/exec_test.go

@@ -159,6 +159,29 @@ exec: helm dependency update ./chart/foo --verify --kube-context dev
 	}
 }
 
+func Test_BuildDeps(t *testing.T) {
+	var buffer bytes.Buffer
+	logger := NewLogger(&buffer, "debug")
+	helm := MockExecer(logger, "dev")
+	helm.BuildDeps("./chart/foo")
+	expected := `Building dependency ./chart/foo
+exec: helm dependency build ./chart/foo --kube-context dev
+`
+	if buffer.String() != expected {
+		t.Errorf("helmexec.BuildDeps()\nactual = %v\nexpect = %v", buffer.String(), expected)
+	}
+
+	buffer.Reset()
+	helm.SetExtraArgs("--verify")
+	helm.BuildDeps("./chart/foo")
+	expected = `Building dependency ./chart/foo
+exec: helm dependency build ./chart/foo --verify --kube-context dev
+`
+	if buffer.String() != expected {
+		t.Errorf("helmexec.BuildDeps()\nactual = %v\nexpect = %v", buffer.String(), expected)
+	}
+}
+
 func Test_DecryptSecret(t *testing.T) {
 	var buffer bytes.Buffer
 	logger := NewLogger(&buffer, "debug")

helmexec/helmexec.go

@@ -7,6 +7,7 @@ type Interface interface {
 
 	AddRepo(name, repository, certfile, keyfile, username, password string) error
 	UpdateRepo() error
+	BuildDeps(chart string) error
 	UpdateDeps(chart string) error
 	SyncRelease(name, chart string, flags ...string) error
 	DiffRelease(name, chart string, flags ...string) error
@@ -16,6 +17,6 @@ type Interface interface {
 	ReleaseStatus(name string) error
 	DeleteRelease(name string, flags ...string) error
 	TestRelease(name string, flags ...string) error
-
+	List(filter string) (string, error)
 	DecryptSecret(name string) (string, error)
 }

helmexec/runner.go

@@ -15,10 +15,13 @@ type Runner interface {
 }
 
 // ShellRunner implemention for shell commands
-type ShellRunner struct{}
+type ShellRunner struct {
+	Dir string
+}
 
 // Execute a shell command
 func (shell ShellRunner) Execute(cmd string, args []string) ([]byte, error) {
 	preparedCmd := exec.Command(cmd, args...)
+	preparedCmd.Dir = shell.Dir
 	return preparedCmd.CombinedOutput()
 }

main.go

@@ -1,35 +1,17 @@
 package main
 
 import (
-	"bytes"
 	"fmt"
-	"log"
-	"os"
-	"os/signal"
-	"path/filepath"
-	"sort"
-	"syscall"
-
-	"os/exec"
-
-	"io/ioutil"
-
-	"strings"
-
 	"github.com/roboll/helmfile/args"
-	"github.com/roboll/helmfile/environment"
+	"github.com/roboll/helmfile/cmd"
 	"github.com/roboll/helmfile/helmexec"
+	"github.com/roboll/helmfile/pkg/app"
 	"github.com/roboll/helmfile/state"
-	"github.com/roboll/helmfile/tmpl"
 	"github.com/urfave/cli"
 	"go.uber.org/zap"
 	"go.uber.org/zap/zapcore"
-)
-
-const (
-	DefaultHelmfile          = "helmfile.yaml"
-	DeprecatedHelmfile       = "charts.yaml"
-	DefaultHelmfileDirectory = "helmfile.d"
+	"os"
+	"strings"
 )
 
 var Version string
@@ -60,11 +42,11 @@ func configureLogging(c *cli.Context) error {
 
 func main() {
 
-	app := cli.NewApp()
-	app.Name = "helmfile"
-	app.Usage = ""
-	app.Version = Version
-	app.Flags = []cli.Flag{
+	cliApp := cli.NewApp()
+	cliApp.Name = "helmfile"
+	cliApp.Usage = ""
+	cliApp.Version = Version
+	cliApp.Flags = []cli.Flag{
 		cli.StringFlag{
 			Name:  "helm-binary, b",
 			Usage: "path to helm binary",
@@ -100,10 +82,14 @@ func main() {
 	--selector tier=frontend,tier!=proxy --selector tier=backend. Will match all frontend, non-proxy releases AND all backend releases.
 	The name of a release can be used as a label. --selector name=myrelease`,
 		},
+		cli.BoolFlag{
+			Name:  "interactive, i",
+			Usage: "Request confirmation before attempting to modify clusters",
+		},
 	}
 
-	app.Before = configureLogging
-	app.Commands = []cli.Command{
+	cliApp.Before = configureLogging
+	cliApp.Commands = []cli.Command{
 		{
 			Name:  "repos",
 			Usage: "sync repositories from state file (helm repo add && helm repo update)",
@@ -115,16 +101,17 @@ func main() {
 				},
 			},
 			Action: func(c *cli.Context) error {
-				return findAndIterateOverDesiredStatesUsingFlags(c, func(state *state.HelmState, helm helmexec.Interface) []error {
+				return cmd.VisitAllDesiredStates(c, func(state *state.HelmState, helm helmexec.Interface, ctx app.Context) (bool, []error) {
 					args := args.GetArgs(c.String("args"), state)
 					if len(args) > 0 {
 						helm.SetExtraArgs(args...)
 					}
-					if c.GlobalString("helm-binary") != "" {
-						helm.SetHelmBinary(c.GlobalString("helm-binary"))
-					}
 
-					return state.SyncRepos(helm)
+					errs := ctx.SyncReposOnce(state, helm)
+
+					ok := len(state.Repositories) > 0 && len(errs) == 0
+
+					return ok, errs
 				})
 			},
 		},
@@ -148,7 +135,7 @@ func main() {
 				},
 			},
 			Action: func(c *cli.Context) error {
-				return findAndIterateOverDesiredStatesUsingFlags(c, func(state *state.HelmState, helm helmexec.Interface) []error {
+				return findAndIterateOverDesiredStatesUsingFlags(c, func(state *state.HelmState, helm helmexec.Interface, _ app.Context) []error {
 					return executeSyncCommand(c, state, helm)
 				})
 			},
@@ -167,8 +154,8 @@ func main() {
 					Usage: "additional value files to be merged into the command",
 				},
 				cli.BoolFlag{
-					Name:  "sync-repos",
-					Usage: "enable a repo sync prior to diffing",
+					Name:  "skip-deps",
+					Usage: "skip running `helm repo update` and `helm dependency build`",
 				},
 				cli.BoolFlag{
 					Name:  "detailed-exitcode",
@@ -185,7 +172,19 @@ func main() {
 				},
 			},
 			Action: func(c *cli.Context) error {
-				return findAndIterateOverDesiredStatesUsingFlags(c, func(state *state.HelmState, helm helmexec.Interface) []error {
+				return findAndIterateOverDesiredStatesUsingFlags(c, func(state *state.HelmState, helm helmexec.Interface, ctx app.Context) []error {
+					if !c.Bool("skip-deps") {
+						if errs := ctx.SyncReposOnce(state, helm); errs != nil && len(errs) > 0 {
+							return errs
+						}
+						if errs := state.BuildDeps(helm); errs != nil && len(errs) > 0 {
+							return errs
+						}
+					}
+					if errs := state.PrepareRelease(helm, "diff"); errs != nil && len(errs) > 0 {
+						return errs
+					}
+
 					_, errs := executeDiffCommand(c, state, helm, c.Bool("detailed-exitcode"), c.Bool("suppress-secrets"))
 					return errs
 				})
@@ -209,9 +208,24 @@ func main() {
 					Value: 0,
 					Usage: "maximum number of concurrent downloads of release charts",
 				},
+				cli.BoolFlag{
+					Name:  "skip-deps",
+					Usage: "skip running `helm repo update` and `helm dependency build`",
+				},
 			},
 			Action: func(c *cli.Context) error {
-				return findAndIterateOverDesiredStatesUsingFlags(c, func(state *state.HelmState, helm helmexec.Interface) []error {
+				return findAndIterateOverDesiredStatesUsingFlags(c, func(state *state.HelmState, helm helmexec.Interface, ctx app.Context) []error {
+					if !c.Bool("skip-deps") {
+						if errs := ctx.SyncReposOnce(state, helm); errs != nil && len(errs) > 0 {
+							return errs
+						}
+						if errs := state.BuildDeps(helm); errs != nil && len(errs) > 0 {
+							return errs
+						}
+					}
+					if errs := state.PrepareRelease(helm, "template"); errs != nil && len(errs) > 0 {
+						return errs
+					}
 					return executeTemplateCommand(c, state, helm)
 				})
 			},
@@ -236,15 +250,14 @@ func main() {
 				},
 			},
 			Action: func(c *cli.Context) error {
-				return findAndIterateOverDesiredStatesUsingFlags(c, func(state *state.HelmState, helm helmexec.Interface) []error {
-					if c.GlobalString("helm-binary") != "" {
-						helm.SetHelmBinary(c.GlobalString("helm-binary"))
-					}
-
+				return findAndIterateOverDesiredStatesUsingFlags(c, func(state *state.HelmState, helm helmexec.Interface, ctx app.Context) []error {
 					values := c.StringSlice("values")
 					args := args.GetArgs(c.String("args"), state)
 					workers := c.Int("concurrency")
-					if errs := state.SyncRepos(helm); errs != nil && len(errs) > 0 {
+					if errs := ctx.SyncReposOnce(state, helm); errs != nil && len(errs) > 0 {
+						return errs
+					}
+					if errs := state.PrepareRelease(helm, "lint"); errs != nil && len(errs) > 0 {
 						return errs
 					}
 					return state.LintReleases(helm, values, args, workers)
@@ -269,13 +282,22 @@ func main() {
 					Value: "",
 					Usage: "pass args to helm exec",
 				},
+				cli.BoolFlag{
+					Name:  "skip-deps",
+					Usage: "skip running `helm repo update` and `helm dependency build`",
+				},
 			},
 			Action: func(c *cli.Context) error {
-				return findAndIterateOverDesiredStatesUsingFlags(c, func(state *state.HelmState, helm helmexec.Interface) []error {
-					if errs := state.SyncRepos(helm); errs != nil && len(errs) > 0 {
-						return errs
+				return findAndIterateOverDesiredStatesUsingFlags(c, func(state *state.HelmState, helm helmexec.Interface, ctx app.Context) []error {
+					if !c.Bool("skip-deps") {
+						if errs := ctx.SyncReposOnce(state, helm); errs != nil && len(errs) > 0 {
+							return errs
+						}
+						if errs := state.BuildDeps(helm); errs != nil && len(errs) > 0 {
+							return errs
+						}
 					}
-					if errs := state.UpdateDeps(helm); errs != nil && len(errs) > 0 {
+					if errs := state.PrepareRelease(helm, "sync"); errs != nil && len(errs) > 0 {
 						return errs
 					}
 					return executeSyncCommand(c, state, helm)
@@ -300,27 +322,26 @@ func main() {
 					Value: "",
 					Usage: "pass args to helm exec",
 				},
-				cli.BoolFlag{
-					Name:  "auto-approve",
-					Usage: "Skip interactive approval before applying",
-				},
 				cli.BoolFlag{
 					Name:  "suppress-secrets",
 					Usage: "suppress secrets in the diff output. highly recommended to specify on CI/CD use-cases",
 				},
 				cli.BoolFlag{
-					Name:  "skip-repo-update",
-					Usage: "skip running `helm repo update` on repositories declared in helmfile",
+					Name:  "skip-deps",
+					Usage: "skip running `helm repo update` and `helm dependency build`",
 				},
 			},
 			Action: func(c *cli.Context) error {
-				return findAndIterateOverDesiredStatesUsingFlags(c, func(st *state.HelmState, helm helmexec.Interface) []error {
-					if !c.Bool("skip-repo-update") {
-						if errs := st.SyncRepos(helm); errs != nil && len(errs) > 0 {
+				return findAndIterateOverDesiredStatesUsingFlags(c, func(st *state.HelmState, helm helmexec.Interface, ctx app.Context) []error {
+					if !c.Bool("skip-deps") {
+						if errs := ctx.SyncReposOnce(st, helm); errs != nil && len(errs) > 0 {
+							return errs
+						}
+						if errs := st.BuildDeps(helm); errs != nil && len(errs) > 0 {
 							return errs
 						}
 					}
-					if errs := st.UpdateDeps(helm); errs != nil && len(errs) > 0 {
+					if errs := st.PrepareRelease(helm, "apply"); errs != nil && len(errs) > 0 {
 						return errs
 					}
 
@@ -364,8 +385,8 @@ Do you really want to apply?
   Helmfile will apply all your changes, as shown above.
 
 `, strings.Join(names, "\n"))
-							autoApprove := c.Bool("auto-approve")
-							if autoApprove || !autoApprove && askForConfirmation(msg) {
+							interactive := c.GlobalBool("interactive")
+							if !interactive || interactive && askForConfirmation(msg) {
 								rs := []state.ReleaseSpec{}
 								for _, r := range releases {
 									rs = append(rs, *r)
@@ -400,16 +421,13 @@ Do you really want to apply?
 				},
 			},
 			Action: func(c *cli.Context) error {
-				return findAndIterateOverDesiredStatesUsingFlags(c, func(state *state.HelmState, helm helmexec.Interface) []error {
+				return findAndIterateOverDesiredStatesUsingFlags(c, func(state *state.HelmState, helm helmexec.Interface, _ app.Context) []error {
 					workers := c.Int("concurrency")
 
 					args := args.GetArgs(c.String("args"), state)
 					if len(args) > 0 {
 						helm.SetExtraArgs(args...)
 					}
-					if c.GlobalString("helm-binary") != "" {
-						helm.SetHelmBinary(c.GlobalString("helm-binary"))
-					}
 
 					return state.ReleaseStatuses(helm, workers)
 				})
@@ -424,17 +442,13 @@ Do you really want to apply?
 					Value: "",
 					Usage: "pass args to helm exec",
 				},
-				cli.BoolFlag{
-					Name:  "auto-approve",
-					Usage: "Skip interactive approval before deleting",
-				},
 				cli.BoolFlag{
 					Name:  "purge",
 					Usage: "purge releases i.e. free release names and histories",
 				},
 			},
 			Action: func(c *cli.Context) error {
-				return findAndIterateOverDesiredStatesUsingFlagsWithReverse(c, true, func(state *state.HelmState, helm helmexec.Interface) []error {
+				return cmd.FindAndIterateOverDesiredStatesUsingFlagsWithReverse(c, true, func(state *state.HelmState, helm helmexec.Interface, _ app.Context) []error {
 					purge := c.Bool("purge")
 
 					args := args.GetArgs(c.String("args"), state)
@@ -442,10 +456,6 @@ Do you really want to apply?
 						helm.SetExtraArgs(args...)
 					}
 
-					if c.GlobalString("helm-binary") != "" {
-						helm.SetHelmBinary(c.GlobalString("helm-binary"))
-					}
-
 					names := make([]string, len(state.Releases))
 					for i, r := range state.Releases {
 						names[i] = fmt.Sprintf("  %s (%s)", r.Name, r.Chart)
@@ -458,8 +468,8 @@ Do you really want to delete?
   Helmfile will delete all your releases, as shown above.
 
 `, strings.Join(names, "\n"))
-					autoApprove := c.Bool("auto-approve")
-					if autoApprove || !autoApprove && askForConfirmation(msg) {
+					interactive := c.GlobalBool("interactive")
+					if !interactive || interactive && askForConfirmation(msg) {
 						return state.DeleteReleases(helm, purge)
 					}
 					return nil
@@ -484,27 +494,30 @@ Do you really want to delete?
 					Value: 300,
 					Usage: "maximum time for tests to run before being considered failed",
 				},
+				cli.IntFlag{
+					Name:  "concurrency",
+					Value: 0,
+					Usage: "maximum number of concurrent helm processes to run, 0 is unlimited",
+				},
 			},
 			Action: func(c *cli.Context) error {
-				return findAndIterateOverDesiredStatesUsingFlags(c, func(state *state.HelmState, helm helmexec.Interface) []error {
+				return findAndIterateOverDesiredStatesUsingFlags(c, func(state *state.HelmState, helm helmexec.Interface, _ app.Context) []error {
 					cleanup := c.Bool("cleanup")
 					timeout := c.Int("timeout")
+					concurrency := c.Int("concurrency")
 
 					args := args.GetArgs(c.String("args"), state)
 					if len(args) > 0 {
 						helm.SetExtraArgs(args...)
 					}
-					if c.GlobalString("helm-binary") != "" {
-						helm.SetHelmBinary(c.GlobalString("helm-binary"))
-					}
 
-					return state.TestReleases(helm, cleanup, timeout)
+					return state.TestReleases(helm, cleanup, timeout, concurrency)
 				})
 			},
 		},
 	}
 
-	err := app.Run(os.Args)
+	err := cliApp.Run(os.Args)
 	if err != nil {
 		fmt.Fprintf(os.Stderr, "%v\n", err)
 		os.Exit(3)
@@ -516,9 +529,6 @@ func executeSyncCommand(c *cli.Context, state *state.HelmState, helm helmexec.In
 	if len(args) > 0 {
 		helm.SetExtraArgs(args...)
 	}
-	if c.GlobalString("helm-binary") != "" {
-		helm.SetHelmBinary(c.GlobalString("helm-binary"))
-	}
 
 	values := c.StringSlice("values")
 	workers := c.Int("concurrency")
@@ -527,17 +537,6 @@ func executeSyncCommand(c *cli.Context, state *state.HelmState, helm helmexec.In
 }
 
 func executeTemplateCommand(c *cli.Context, state *state.HelmState, helm helmexec.Interface) []error {
-	if c.GlobalString("helm-binary") != "" {
-		helm.SetHelmBinary(c.GlobalString("helm-binary"))
-	}
-	if errs := state.SyncRepos(helm); errs != nil && len(errs) > 0 {
-		return errs
-	}
-
-	if errs := state.UpdateDeps(helm); errs != nil && len(errs) > 0 {
-		return errs
-	}
-
 	args := args.GetArgs(c.String("args"), state)
 	values := c.StringSlice("values")
 	workers := c.Int("concurrency")
@@ -550,388 +549,14 @@ func executeDiffCommand(c *cli.Context, st *state.HelmState, helm helmexec.Inter
 	if len(args) > 0 {
 		helm.SetExtraArgs(args...)
 	}
-	if c.GlobalString("helm-binary") != "" {
-		helm.SetHelmBinary(c.GlobalString("helm-binary"))
-	}
-
-	if c.Bool("sync-repos") {
-		if errs := st.SyncRepos(helm); errs != nil && len(errs) > 0 {
-			return []*state.ReleaseSpec{}, errs
-		}
-	}
 
 	values := c.StringSlice("values")
 	workers := c.Int("concurrency")
+	triggerCleanupEvents := c.Command.HasName("diff")
 
-	return st.DiffReleases(helm, values, workers, detailedExitCode, suppressSecrets)
+	return st.DiffReleases(helm, values, workers, detailedExitCode, suppressSecrets, triggerCleanupEvents)
 }
 
-type app struct {
-	kubeContext       string
-	logger            *zap.SugaredLogger
-	readFile          func(string) ([]byte, error)
-	glob              func(string) ([]string, error)
-	abs               func(string) (string, error)
-	fileExistsAt      func(string) bool
-	directoryExistsAt func(string) bool
-	reverse           bool
-}
-
-func findAndIterateOverDesiredStatesUsingFlags(c *cli.Context, converge func(*state.HelmState, helmexec.Interface) []error) error {
-	return findAndIterateOverDesiredStatesUsingFlagsWithReverse(c, false, converge)
-}
-
-func findAndIterateOverDesiredStatesUsingFlagsWithReverse(c *cli.Context, reverse bool, converge func(*state.HelmState, helmexec.Interface) []error) error {
-	fileOrDir := c.GlobalString("file")
-	kubeContext := c.GlobalString("kube-context")
-	namespace := c.GlobalString("namespace")
-	selectors := c.GlobalStringSlice("selector")
-	logger := c.App.Metadata["logger"].(*zap.SugaredLogger)
-
-	env := c.GlobalString("environment")
-	if env == "" {
-		env = state.DefaultEnv
-	}
-
-	app := &app{
-		readFile:          ioutil.ReadFile,
-		glob:              filepath.Glob,
-		abs:               filepath.Abs,
-		fileExistsAt:      fileExistsAt,
-		directoryExistsAt: directoryExistsAt,
-		kubeContext:       kubeContext,
-		logger:            logger,
-		reverse:           reverse,
-	}
-	if err := app.FindAndIterateOverDesiredStates(fileOrDir, converge, namespace, selectors, env); err != nil {
-		switch e := err.(type) {
-		case *noMatchingHelmfileError:
-			return cli.NewExitError(e.Error(), 2)
-		}
-		return err
-	}
-	return nil
-}
-
-type noMatchingHelmfileError struct {
-	selectors []string
-	env       string
-}
-
-func (e *noMatchingHelmfileError) Error() string {
-	return fmt.Sprintf(
-		"err: no releases found that matches specified selector(%s) and environment(%s), in any helmfile",
-		strings.Join(e.selectors, ", "),
-		e.env,
-	)
-}
-
-func prependLineNumbers(text string) string {
-	buf := bytes.NewBufferString("")
-	lines := strings.Split(text, "\n")
-	for i, line := range lines {
-		buf.WriteString(fmt.Sprintf("%2d: %s\n", i, line))
-	}
-	return buf.String()
-}
-
-type twoPassRenderer struct {
-	reader    func(string) ([]byte, error)
-	env       string
-	namespace string
-	filename  string
-	logger    *zap.SugaredLogger
-	abs       func(string) (string, error)
-}
-
-func (r *twoPassRenderer) renderEnvironment(content []byte) environment.Environment {
-	firstPassEnv := environment.Environment{Name: r.env, Values: map[string]interface{}(nil)}
-	firstPassRenderer := tmpl.NewFirstPassRenderer(filepath.Dir(r.filename), firstPassEnv)
-
-	// parse as much as we can, tolerate errors, this is a preparse
-	yamlBuf, err := firstPassRenderer.RenderTemplateContentToBuffer(content)
-	if err != nil && logger != nil {
-		r.logger.Debugf("first-pass rendering input of \"%s\":\n%s", r.filename, prependLineNumbers(string(content)))
-	}
-	c := state.NewCreator(r.logger, r.reader, r.abs)
-	c.Strict = false
-	// create preliminary state, as we may have an environment. Tolerate errors.
-	prestate, err := c.CreateFromYaml(yamlBuf.Bytes(), r.filename, r.env)
-	if err != nil && r.logger != nil {
-		switch err.(type) {
-		case *state.StateLoadError:
-			r.logger.Infof("could not deduce `environment:` block, configuring only .Environment.Name. error: %v", err)
-		}
-		r.logger.Debugf("error in first-pass rendering: result of \"%s\":\n%s", r.filename, prependLineNumbers(yamlBuf.String()))
-	}
-	if prestate != nil {
-		firstPassEnv = prestate.Env
-	}
-	return firstPassEnv
-}
-
-func (r *twoPassRenderer) renderTemplate(content []byte) (*bytes.Buffer, error) {
-	// try a first pass render. This will always succeed, but can produce a limited env
-	firstPassEnv := r.renderEnvironment(content)
-
-	secondPassRenderer := tmpl.NewFileRenderer(r.reader, filepath.Dir(r.filename), firstPassEnv, r.namespace)
-	yamlBuf, err := secondPassRenderer.RenderTemplateContentToBuffer(content)
-	if err != nil {
-		if r.logger != nil {
-			r.logger.Debugf("second-pass rendering failed, input of \"%s\":\n%s", r.filename, prependLineNumbers(string(content)))
-		}
-		return nil, err
-	}
-	if r.logger != nil {
-		r.logger.Debugf("second-pass rendering result of \"%s\":\n%s", r.filename, prependLineNumbers(yamlBuf.String()))
-	}
-	return yamlBuf, nil
-}
-
-func (a *app) FindAndIterateOverDesiredStates(fileOrDir string, converge func(*state.HelmState, helmexec.Interface) []error, namespace string, selectors []string, env string) error {
-	desiredStateFiles, err := a.findDesiredStateFiles(fileOrDir)
-	if err != nil {
-		return err
-	}
-	noMatchInHelmfiles := true
-	for _, f := range desiredStateFiles {
-		a.logger.Debugf("Processing %s", f)
-
-		content, err := a.readFile(f)
-		if err != nil {
-			return err
-		}
-		// render template, in two runs
-		r := &twoPassRenderer{
-			reader:    a.readFile,
-			env:       env,
-			namespace: namespace,
-			filename:  f,
-			logger:    a.logger,
-			abs:       a.abs,
-		}
-		yamlBuf, err := r.renderTemplate(content)
-		if err != nil {
-			return fmt.Errorf("error during %s parsing: %v", f, err)
-		}
-
-		st, noMatchInThisHelmfile, err := a.loadDesiredStateFromYaml(
-			yamlBuf.Bytes(),
-			f,
-			namespace,
-			selectors,
-			env,
-		)
-		helm := helmexec.New(a.logger, a.kubeContext)
-
-		if err != nil {
-			switch stateLoadErr := err.(type) {
-			// Addresses https://github.com/roboll/helmfile/issues/279
-			case *state.StateLoadError:
-				switch stateLoadErr.Cause.(type) {
-				case *state.UndefinedEnvError:
-					continue
-				default:
-					return err
-				}
-			default:
-				return err
-			}
-		}
-
-		errs := []error{}
-
-		if len(st.Helmfiles) > 0 {
-			noMatchInSubHelmfiles := true
-			for _, m := range st.Helmfiles {
-				if err := a.FindAndIterateOverDesiredStates(m, converge, namespace, selectors, env); err != nil {
-					switch err.(type) {
-					case *noMatchingHelmfileError:
-
-					default:
-						return fmt.Errorf("failed processing %s: %v", m, err)
-					}
-				} else {
-					noMatchInSubHelmfiles = false
-				}
-			}
-			noMatchInHelmfiles = noMatchInHelmfiles && noMatchInSubHelmfiles
-		} else {
-			noMatchInHelmfiles = noMatchInHelmfiles && noMatchInThisHelmfile
-			if noMatchInThisHelmfile {
-				continue
-			}
-			errs = converge(st, helm)
-		}
-
-		if err := clean(st, errs); err != nil {
-			return err
-		}
-	}
-	if noMatchInHelmfiles {
-		return &noMatchingHelmfileError{selectors, env}
-	}
-	return nil
-}
-
-func (a *app) findDesiredStateFiles(specifiedPath string) ([]string, error) {
-	var helmfileDir string
-	if specifiedPath != "" {
-		if a.fileExistsAt(specifiedPath) {
-			return []string{specifiedPath}, nil
-		} else if a.directoryExistsAt(specifiedPath) {
-			helmfileDir = specifiedPath
-		} else {
-			return []string{}, fmt.Errorf("specified state file %s is not found", specifiedPath)
-		}
-	} else {
-		var defaultFile string
-		if a.fileExistsAt(DefaultHelmfile) {
-			defaultFile = DefaultHelmfile
-		} else if a.fileExistsAt(DeprecatedHelmfile) {
-			log.Printf(
-				"warn: %s is being loaded: %s is deprecated in favor of %s. See https://github.com/roboll/helmfile/issues/25 for more information",
-				DeprecatedHelmfile,
-				DeprecatedHelmfile,
-				DefaultHelmfile,
-			)
-			defaultFile = DeprecatedHelmfile
-		}
-
-		if a.directoryExistsAt(DefaultHelmfileDirectory) {
-			if defaultFile != "" {
-				return []string{}, fmt.Errorf("configuration conlict error: you can have either %s or %s, but not both", defaultFile, DefaultHelmfileDirectory)
-			}
-
-			helmfileDir = DefaultHelmfileDirectory
-		} else if defaultFile != "" {
-			return []string{defaultFile}, nil
-		} else {
-			return []string{}, fmt.Errorf("no state file found. It must be named %s/*.yaml, %s, or %s, or otherwise specified with the --file flag", DefaultHelmfileDirectory, DefaultHelmfile, DeprecatedHelmfile)
-		}
-	}
-
-	files, err := a.glob(filepath.Join(helmfileDir, "*.yaml"))
-	if err != nil {
-		return []string{}, err
-	}
-	sort.Slice(files, func(i, j int) bool {
-		return files[i] < files[j]
-	})
-	return files, nil
-}
-
-func fileExistsAt(path string) bool {
-	fileInfo, err := os.Stat(path)
-	return err == nil && fileInfo.Mode().IsRegular()
-}
-
-func directoryExistsAt(path string) bool {
-	fileInfo, err := os.Stat(path)
-	return err == nil && fileInfo.Mode().IsDir()
-}
-
-func (a *app) loadDesiredStateFromYaml(yaml []byte, file string, namespace string, labels []string, env string) (*state.HelmState, bool, error) {
-	c := state.NewCreator(a.logger, a.readFile, a.abs)
-	st, err := c.CreateFromYaml(yaml, file, env)
-	if err != nil {
-		return nil, false, err
-	}
-
-	helmfiles := []string{}
-	for _, globPattern := range st.Helmfiles {
-		helmfileRelativePattern := st.JoinBase(globPattern)
-		matches, err := a.glob(helmfileRelativePattern)
-		if err != nil {
-			return nil, false, fmt.Errorf("failed processing %s: %v", globPattern, err)
-		}
-		sort.Strings(matches)
-
-		helmfiles = append(helmfiles, matches...)
-	}
-	st.Helmfiles = helmfiles
-
-	if a.reverse {
-		rev := func(i, j int) bool {
-			return j < i
-		}
-		sort.Slice(st.Releases, rev)
-		sort.Slice(st.Helmfiles, rev)
-	}
-
-	if a.kubeContext != "" {
-		if st.Context != "" {
-			log.Printf("err: Cannot use option --kube-context and set attribute context.")
-			os.Exit(1)
-		}
-		st.Context = a.kubeContext
-	}
-	if namespace != "" {
-		if st.Namespace != "" {
-			log.Printf("err: Cannot use option --namespace and set attribute namespace.")
-			os.Exit(1)
-		}
-		st.Namespace = namespace
-	}
-
-	if len(labels) > 0 {
-		err = st.FilterReleases(labels)
-		if err != nil {
-			return nil, false, err
-		}
-	}
-
-	releaseNameCounts := map[string]int{}
-	for _, r := range st.Releases {
-		releaseNameCounts[r.Name]++
-	}
-	for name, c := range releaseNameCounts {
-		if c > 1 {
-			return nil, false, fmt.Errorf("duplicate release \"%s\" found: there were %d releases named \"%s\" matching specified selector", name, c, name)
-		}
-	}
-
-	sigs := make(chan os.Signal, 1)
-	signal.Notify(sigs, syscall.SIGINT, syscall.SIGTERM)
-	go func() {
-		sig := <-sigs
-
-		errs := []error{fmt.Errorf("Received [%s] to shutdown ", sig)}
-		clean(st, errs)
-	}()
-
-	return st, len(st.Releases) == 0, nil
-}
-
-func clean(st *state.HelmState, errs []error) error {
-	if errs == nil {
-		errs = []error{}
-	}
-
-	cleanErrs := st.Clean()
-	if cleanErrs != nil {
-		errs = append(errs, cleanErrs...)
-	}
-
-	if errs != nil && len(errs) > 0 {
-		for _, err := range errs {
-			switch e := err.(type) {
-			case *state.ReleaseError:
-				fmt.Printf("err: release \"%s\" in \"%s\" failed: %v\n", e.Name, st.FilePath, e)
-			default:
-				fmt.Printf("err: %v\n", e)
-			}
-		}
-		switch e := errs[0].(type) {
-		case *exec.ExitError:
-			// Propagate any non-zero exit status from the external command like `helm` that is failed under the hood
-			status := e.Sys().(syscall.WaitStatus)
-			os.Exit(status.ExitStatus())
-		case *state.DiffError:
-			os.Exit(e.Code)
-		default:
-			os.Exit(1)
-		}
-	}
-	return nil
+func findAndIterateOverDesiredStatesUsingFlags(c *cli.Context, converge func(*state.HelmState, helmexec.Interface, app.Context) []error) error {
+	return cmd.FindAndIterateOverDesiredStatesUsingFlagsWithReverse(c, false, converge)
 }

pkg/app/app.go

@@ -0,0 +1,391 @@
+package app
+
+import (
+	"fmt"
+	"github.com/roboll/helmfile/helmexec"
+	"github.com/roboll/helmfile/state"
+	"go.uber.org/zap"
+	"io/ioutil"
+	"log"
+	"os"
+	"os/signal"
+	"path/filepath"
+	"sort"
+	"syscall"
+)
+
+type App struct {
+	KubeContext string
+	Logger      *zap.SugaredLogger
+	Reverse     bool
+	Env         string
+	Namespace   string
+	Selectors   []string
+
+	readFile          func(string) ([]byte, error)
+	glob              func(string) ([]string, error)
+	abs               func(string) (string, error)
+	fileExistsAt      func(string) bool
+	directoryExistsAt func(string) bool
+
+	getwd func() (string, error)
+	chdir func(string) error
+}
+
+func Init(app *App) *App {
+	app.readFile = ioutil.ReadFile
+	app.glob = filepath.Glob
+	app.abs = filepath.Abs
+	app.getwd = os.Getwd
+	app.chdir = os.Chdir
+	app.fileExistsAt = fileExistsAt
+	app.directoryExistsAt = directoryExistsAt
+	return app
+}
+
+func (a *App) within(dir string, do func() error) error {
+	if dir == "." {
+		return do()
+	}
+
+	prev, err := a.getwd()
+	if err != nil {
+		return fmt.Errorf("failed getting current working direcotyr: %v", err)
+	}
+
+	absDir, err := a.abs(dir)
+	if err != nil {
+		return err
+	}
+
+	a.Logger.Debugf("changing working directory to \"%s\"", absDir)
+
+	if err := a.chdir(absDir); err != nil {
+		return fmt.Errorf("failed changing working directory to \"%s\": %v", absDir, err)
+	}
+
+	appErr := do()
+
+	a.Logger.Debugf("changing working directory back to \"%s\"", prev)
+
+	if chdirBackErr := a.chdir(prev); chdirBackErr != nil {
+		if appErr != nil {
+			a.Logger.Warnf("%v", appErr)
+		}
+		return fmt.Errorf("failed chaging working directory back to \"%s\": %v", prev, chdirBackErr)
+	}
+
+	return appErr
+}
+
+func (a *App) visitStateFiles(fileOrDir string, do func(string) error) error {
+	desiredStateFiles, err := a.findDesiredStateFiles(fileOrDir)
+	if err != nil {
+		return err
+	}
+
+	for _, relPath := range desiredStateFiles {
+		var file string
+		var dir string
+		if a.directoryExistsAt(relPath) {
+			file = relPath
+			dir = relPath
+		} else {
+			file = filepath.Base(relPath)
+			dir = filepath.Dir(relPath)
+		}
+
+		a.Logger.Debugf("processing file \"%s\" in directory \"%s\"", file, dir)
+
+		err := a.within(dir, func() error {
+			return do(file)
+		})
+		if err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func (a *App) VisitDesiredStates(fileOrDir string, converge func(*state.HelmState, helmexec.Interface) (bool, []error)) error {
+	noMatchInHelmfiles := true
+	err := a.visitStateFiles(fileOrDir, func(f string) error {
+		content, err := a.readFile(f)
+		if err != nil {
+			return err
+		}
+		// render template, in two runs
+		r := &twoPassRenderer{
+			reader:    a.readFile,
+			env:       a.Env,
+			namespace: a.Namespace,
+			filename:  f,
+			logger:    a.Logger,
+			abs:       a.abs,
+		}
+		yamlBuf, err := r.renderTemplate(content)
+		if err != nil {
+			return fmt.Errorf("error during %s parsing: %v", f, err)
+		}
+
+		st, err := a.loadDesiredStateFromYaml(
+			yamlBuf.Bytes(),
+			f,
+			a.Namespace,
+			a.Env,
+		)
+
+		helm := helmexec.New(a.Logger, a.KubeContext)
+
+		if err != nil {
+			switch stateLoadErr := err.(type) {
+			// Addresses https://github.com/roboll/helmfile/issues/279
+			case *state.StateLoadError:
+				switch stateLoadErr.Cause.(type) {
+				case *state.UndefinedEnvError:
+					return nil
+				default:
+					return err
+				}
+			default:
+				return err
+			}
+		}
+
+		errs := []error{}
+
+		if len(st.Helmfiles) > 0 {
+			noMatchInSubHelmfiles := true
+			for _, m := range st.Helmfiles {
+				if err := a.VisitDesiredStates(m, converge); err != nil {
+					switch err.(type) {
+					case *NoMatchingHelmfileError:
+
+					default:
+						return fmt.Errorf("failed processing %s: %v", m, err)
+					}
+				} else {
+					noMatchInSubHelmfiles = false
+				}
+			}
+			noMatchInHelmfiles = noMatchInHelmfiles && noMatchInSubHelmfiles
+		} else {
+			var err error
+			st, err = st.ExecuteTemplates()
+			if err != nil {
+				return fmt.Errorf("failed executing release templates in \"%s\": %v", f, err)
+			}
+
+			var processed bool
+			processed, errs = converge(st, helm)
+			noMatchInHelmfiles = noMatchInHelmfiles && !processed
+		}
+
+		return clean(st, errs)
+	})
+	if err != nil {
+		return err
+	}
+	if noMatchInHelmfiles {
+		return &NoMatchingHelmfileError{selectors: a.Selectors, env: a.Env}
+	}
+	return nil
+}
+
+func (a *App) VisitDesiredStatesWithReleasesFiltered(fileOrDir string, converge func(*state.HelmState, helmexec.Interface) []error) error {
+	selectors := a.Selectors
+
+	err := a.VisitDesiredStates(fileOrDir, func(st *state.HelmState, helm helmexec.Interface) (bool, []error) {
+		if len(selectors) > 0 {
+			err := st.FilterReleases(selectors)
+			if err != nil {
+				return false, []error{err}
+			}
+		}
+
+		releaseNameCounts := map[string]int{}
+		for _, r := range st.Releases {
+			releaseNameCounts[r.Name]++
+		}
+		for name, c := range releaseNameCounts {
+			if c > 1 {
+				return false, []error{fmt.Errorf("duplicate release \"%s\" found: there were %d releases named \"%s\" matching specified selector", name, c, name)}
+			}
+		}
+
+		errs := converge(st, helm)
+
+		processed := len(st.Releases) != 0 && len(errs) == 0
+
+		return processed, errs
+	})
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
+func (a *App) findStateFilesInAbsPaths(specifiedPath string) ([]string, error) {
+	rels, err := a.findDesiredStateFiles(specifiedPath)
+	if err != nil {
+		return rels, err
+	}
+
+	files := make([]string, len(rels))
+	for i := range rels {
+		files[i], err = filepath.Abs(rels[i])
+		if err != nil {
+			return []string{}, err
+		}
+	}
+	return files, nil
+}
+
+func (a *App) findDesiredStateFiles(specifiedPath string) ([]string, error) {
+	var helmfileDir string
+	if specifiedPath != "" {
+		if a.fileExistsAt(specifiedPath) {
+			return []string{specifiedPath}, nil
+		} else if a.directoryExistsAt(specifiedPath) {
+			helmfileDir = specifiedPath
+		} else {
+			return []string{}, fmt.Errorf("specified state file %s is not found", specifiedPath)
+		}
+	} else {
+		var defaultFile string
+		if a.fileExistsAt(DefaultHelmfile) {
+			defaultFile = DefaultHelmfile
+		} else if a.fileExistsAt(DeprecatedHelmfile) {
+			log.Printf(
+				"warn: %s is being loaded: %s is deprecated in favor of %s. See https://github.com/roboll/helmfile/issues/25 for more information",
+				DeprecatedHelmfile,
+				DeprecatedHelmfile,
+				DefaultHelmfile,
+			)
+			defaultFile = DeprecatedHelmfile
+		}
+
+		if a.directoryExistsAt(DefaultHelmfileDirectory) {
+			if defaultFile != "" {
+				return []string{}, fmt.Errorf("configuration conlict error: you can have either %s or %s, but not both", defaultFile, DefaultHelmfileDirectory)
+			}
+
+			helmfileDir = DefaultHelmfileDirectory
+		} else if defaultFile != "" {
+			return []string{defaultFile}, nil
+		} else {
+			return []string{}, fmt.Errorf("no state file found. It must be named %s/*.yaml, %s, or %s, or otherwise specified with the --file flag", DefaultHelmfileDirectory, DefaultHelmfile, DeprecatedHelmfile)
+		}
+	}
+
+	files, err := a.glob(filepath.Join(helmfileDir, "*.yaml"))
+	if err != nil {
+		return []string{}, err
+	}
+	sort.Slice(files, func(i, j int) bool {
+		return files[i] < files[j]
+	})
+	return files, nil
+}
+
+func fileExistsAt(path string) bool {
+	fileInfo, err := os.Stat(path)
+	return err == nil && fileInfo.Mode().IsRegular()
+}
+
+func directoryExistsAt(path string) bool {
+	fileInfo, err := os.Stat(path)
+	return err == nil && fileInfo.Mode().IsDir()
+}
+
+func (a *App) loadDesiredStateFromYaml(yaml []byte, file string, namespace string, env string) (*state.HelmState, error) {
+	c := state.NewCreator(a.Logger, a.readFile, a.abs)
+	st, err := c.CreateFromYaml(yaml, file, env)
+	if err != nil {
+		return nil, err
+	}
+
+	helmfiles := []string{}
+	for _, globPattern := range st.Helmfiles {
+		var absPathPattern string
+		if filepath.IsAbs(globPattern) {
+			absPathPattern = globPattern
+		} else {
+			absPathPattern = st.JoinBase(globPattern)
+		}
+		matches, err := a.glob(absPathPattern)
+		if err != nil {
+			return nil, fmt.Errorf("failed processing %s: %v", globPattern, err)
+		}
+		sort.Strings(matches)
+
+		helmfiles = append(helmfiles, matches...)
+	}
+	st.Helmfiles = helmfiles
+
+	if a.Reverse {
+		rev := func(i, j int) bool {
+			return j < i
+		}
+		sort.Slice(st.Releases, rev)
+		sort.Slice(st.Helmfiles, rev)
+	}
+
+	if a.KubeContext != "" {
+		if st.HelmDefaults.KubeContext != "" {
+			log.Printf("err: Cannot use option --kube-context and set attribute helmDefaults.kubeContext.")
+			os.Exit(1)
+		}
+		st.HelmDefaults.KubeContext = a.KubeContext
+	}
+	if namespace != "" {
+		if st.Namespace != "" {
+			log.Printf("err: Cannot use option --namespace and set attribute namespace.")
+			os.Exit(1)
+		}
+		st.Namespace = namespace
+	}
+
+	sigs := make(chan os.Signal, 1)
+	signal.Notify(sigs, syscall.SIGINT, syscall.SIGTERM)
+	go func() {
+		sig := <-sigs
+
+		errs := []error{fmt.Errorf("Received [%s] to shutdown ", sig)}
+		_ = clean(st, errs)
+		// See http://tldp.org/LDP/abs/html/exitcodes.html
+		switch sig {
+		case syscall.SIGINT:
+			os.Exit(130)
+		case syscall.SIGTERM:
+			os.Exit(143)
+		}
+	}()
+
+	return st, nil
+}
+
+func clean(st *state.HelmState, errs []error) error {
+	if errs == nil {
+		errs = []error{}
+	}
+
+	cleanErrs := st.Clean()
+	if cleanErrs != nil {
+		errs = append(errs, cleanErrs...)
+	}
+
+	if errs != nil && len(errs) > 0 {
+		for _, err := range errs {
+			switch e := err.(type) {
+			case *state.ReleaseError:
+				fmt.Printf("err: release \"%s\" in \"%s\" failed: %v\n", e.Name, st.FilePath, e)
+			default:
+				fmt.Printf("err: %v\n", e)
+			}
+		}
+		return errs[0]
+	}
+	return nil
+}

pkg/app/app_test.go

@@ -0,0 +1,403 @@
+package app
+
+import (
+	"fmt"
+	"github.com/roboll/helmfile/helmexec"
+	"github.com/roboll/helmfile/state"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"reflect"
+	"strings"
+	"testing"
+)
+
+type testFs struct {
+	wd    string
+	dirs  map[string]bool
+	files map[string]string
+}
+
+func appWithFs(app *App, files map[string]string) *App {
+	fs := newTestFs(files)
+	return injectFs(app, fs)
+}
+
+func injectFs(app *App, fs *testFs) *App {
+	app.readFile = fs.readFile
+	app.glob = fs.glob
+	app.abs = fs.abs
+	app.getwd = fs.getwd
+	app.chdir = fs.chdir
+	app.fileExistsAt = fs.fileExistsAt
+	app.directoryExistsAt = fs.directoryExistsAt
+	return app
+}
+
+func newTestFs(files map[string]string) *testFs {
+	dirs := map[string]bool{}
+	for abs, _ := range files {
+		d := filepath.Dir(abs)
+		dirs[d] = true
+	}
+	return &testFs{
+		wd:    "/path/to",
+		dirs:  dirs,
+		files: files,
+	}
+}
+
+func (f *testFs) fileExistsAt(path string) bool {
+	var ok bool
+	if strings.Contains(path, "/") {
+		_, ok = f.files[path]
+	} else {
+		_, ok = f.files[filepath.Join(f.wd, path)]
+	}
+	return ok
+}
+
+func (f *testFs) directoryExistsAt(path string) bool {
+	var ok bool
+	if strings.Contains(path, "/") {
+		_, ok = f.dirs[path]
+	} else {
+		_, ok = f.dirs[filepath.Join(f.wd, path)]
+	}
+	return ok
+}
+
+func (f *testFs) readFile(filename string) ([]byte, error) {
+	var str string
+	var ok bool
+	if strings.Contains(filename, "/") {
+		str, ok = f.files[filename]
+	} else {
+		str, ok = f.files[filepath.Join(f.wd, filename)]
+	}
+	if !ok {
+		return []byte(nil), fmt.Errorf("no file found: %s", filename)
+	}
+	return []byte(str), nil
+}
+
+func (f *testFs) glob(pattern string) ([]string, error) {
+	matches := []string{}
+	for name, _ := range f.files {
+		matched, err := filepath.Match(pattern, name)
+		if err != nil {
+			return nil, err
+		}
+		if matched {
+			matches = append(matches, name)
+		}
+	}
+	if len(matches) == 0 {
+		return []string(nil), fmt.Errorf("no file matched: %s", pattern)
+	}
+	return matches, nil
+}
+
+func (f *testFs) abs(path string) (string, error) {
+	var p string
+	if path[0] == '/' {
+		p = path
+	} else {
+		p = filepath.Join(f.wd, path)
+	}
+	return filepath.Clean(p), nil
+}
+
+func (f *testFs) getwd() (string, error) {
+	return f.wd, nil
+}
+
+func (f *testFs) chdir(dir string) error {
+	if dir == "/path/to" || dir == "/path/to/helmfile.d" {
+		f.wd = dir
+		return nil
+	}
+	return fmt.Errorf("unexpected chdir \"%s\"", dir)
+}
+
+// See https://github.com/roboll/helmfile/issues/193
+func TestVisitDesiredStatesWithReleasesFiltered(t *testing.T) {
+	files := map[string]string{
+		"/path/to/helmfile.yaml": `
+helmfiles:
+- helmfile.d/a*.yaml
+- helmfile.d/b*.yaml
+`,
+		"/path/to/helmfile.d/a1.yaml": `
+releases:
+- name: zipkin
+  chart: stable/zipkin
+`,
+		"/path/to/helmfile.d/a2.yaml": `
+releases:
+- name: prometheus
+  chart: stable/prometheus
+`,
+		"/path/to/helmfile.d/b.yaml": `
+releases:
+- name: grafana
+  chart: stable/grafana
+`,
+	}
+	noop := func(st *state.HelmState, helm helmexec.Interface) []error {
+		return []error{}
+	}
+
+	testcases := []struct {
+		name      string
+		expectErr bool
+	}{
+		{name: "prometheus", expectErr: false},
+		{name: "zipkin", expectErr: false},
+		{name: "grafana", expectErr: false},
+		{name: "elasticsearch", expectErr: true},
+	}
+
+	for _, testcase := range testcases {
+		app := appWithFs(&App{
+			KubeContext: "default",
+			Logger:      helmexec.NewLogger(os.Stderr, "debug"),
+			Selectors:   []string{fmt.Sprintf("name=%s", testcase.name)},
+			Namespace:   "",
+			Env:         "default",
+		}, files)
+		err := app.VisitDesiredStatesWithReleasesFiltered(
+			"helmfile.yaml", noop,
+		)
+		if testcase.expectErr && err == nil {
+			t.Errorf("error expected but not happened for name=%s", testcase.name)
+		} else if !testcase.expectErr && err != nil {
+			t.Errorf("unexpected error for name=%s: %v", testcase.name, err)
+		}
+	}
+}
+
+// See https://github.com/roboll/helmfile/issues/320
+func TestVisitDesiredStatesWithReleasesFiltered_UndefinedEnv(t *testing.T) {
+	files := map[string]string{
+		"/path/to/helmfile.yaml": `
+environments:
+  prod:
+
+helmfiles:
+- helmfile.d/a*.yaml
+`,
+		"/path/to/helmfile.d/a1.yaml": `
+environments:
+  prod:
+
+releases:
+- name: zipkin
+  chart: stable/zipkin
+`,
+	}
+	noop := func(st *state.HelmState, helm helmexec.Interface) []error {
+		return []error{}
+	}
+
+	testcases := []struct {
+		name      string
+		expectErr bool
+	}{
+		{name: "undefined_env", expectErr: true},
+		{name: "default", expectErr: false},
+		{name: "prod", expectErr: false},
+	}
+
+	for _, testcase := range testcases {
+		app := appWithFs(&App{
+			KubeContext: "default",
+			Logger:      helmexec.NewLogger(os.Stderr, "debug"),
+			Namespace:   "",
+			Selectors:   []string{},
+			Env:         testcase.name,
+		}, files)
+		err := app.VisitDesiredStatesWithReleasesFiltered(
+			"helmfile.yaml", noop,
+		)
+		if testcase.expectErr && err == nil {
+			t.Errorf("error expected but not happened for environment=%s", testcase.name)
+		} else if !testcase.expectErr && err != nil {
+			t.Errorf("unexpected error for environment=%s: %v", testcase.name, err)
+		}
+	}
+}
+
+// See https://github.com/roboll/helmfile/issues/322
+func TestVisitDesiredStatesWithReleasesFiltered_Selectors(t *testing.T) {
+	files := map[string]string{
+		"/path/to/helmfile.yaml": `
+helmfiles:
+- helmfile.d/a*.yaml
+- helmfile.d/b*.yaml
+`,
+		"/path/to/helmfile.d/a1.yaml": `
+releases:
+- name: zipkin
+  chart: stable/zipkin
+`,
+		"/path/to/helmfile.d/a2.yaml": `
+releases:
+- name: prometheus
+  chart: stable/prometheus
+`,
+		"/path/to/helmfile.d/b.yaml": `
+releases:
+- name: grafana
+  chart: stable/grafana
+- name: foo
+  chart: charts/foo
+  labels:
+    duplicated: yes
+- name: foo
+  chart: charts/foo
+  labels:
+    duplicated: yes
+`,
+	}
+
+	testcases := []struct {
+		label         string
+		expectedCount int
+		expectErr     bool
+		errMsg        string
+	}{
+		{label: "name=prometheus", expectedCount: 1, expectErr: false},
+		{label: "name=", expectedCount: 0, expectErr: true, errMsg: "failed processing /path/to/helmfile.d/a1.yaml: Malformed label: name=. Expected label in form k=v or k!=v"},
+		{label: "name!=", expectedCount: 0, expectErr: true, errMsg: "failed processing /path/to/helmfile.d/a1.yaml: Malformed label: name!=. Expected label in form k=v or k!=v"},
+		{label: "name", expectedCount: 0, expectErr: true, errMsg: "failed processing /path/to/helmfile.d/a1.yaml: Malformed label: name. Expected label in form k=v or k!=v"},
+		// See https://github.com/roboll/helmfile/issues/193
+		{label: "duplicated=yes", expectedCount: 0, expectErr: true, errMsg: "failed processing /path/to/helmfile.d/b.yaml: duplicate release \"foo\" found: there were 2 releases named \"foo\" matching specified selector"},
+	}
+
+	for _, testcase := range testcases {
+		actual := []string{}
+
+		collectReleases := func(st *state.HelmState, helm helmexec.Interface) []error {
+			for _, r := range st.Releases {
+				actual = append(actual, r.Name)
+			}
+			return []error{}
+		}
+
+		app := appWithFs(&App{
+			KubeContext: "default",
+			Logger:      helmexec.NewLogger(os.Stderr, "debug"),
+			Namespace:   "",
+			Selectors:   []string{testcase.label},
+			Env:         "default",
+		}, files)
+
+		err := app.VisitDesiredStatesWithReleasesFiltered(
+			"helmfile.yaml", collectReleases,
+		)
+		if testcase.expectErr {
+			if err == nil {
+				t.Errorf("error expected but not happened for selector %s", testcase.label)
+			} else if err.Error() != testcase.errMsg {
+				t.Errorf("unexpected error message: expected=\"%s\", actual=\"%s\"", testcase.errMsg, err.Error())
+			}
+		} else if !testcase.expectErr && err != nil {
+			t.Errorf("unexpected error for selector %s: %v", testcase.label, err)
+		}
+		if len(actual) != testcase.expectedCount {
+			t.Errorf("unexpected release count for selector %s: expected=%d, actual=%d", testcase.label, testcase.expectedCount, len(actual))
+		}
+	}
+}
+
+// See https://github.com/roboll/helmfile/issues/312
+func TestVisitDesiredStatesWithReleasesFiltered_ReverseOrder(t *testing.T) {
+	files := map[string]string{
+		"/path/to/helmfile.yaml": `
+helmfiles:
+- helmfile.d/a*.yaml
+- helmfile.d/b*.yaml
+`,
+		"/path/to/helmfile.d/a1.yaml": `
+releases:
+- name: zipkin
+  chart: stable/zipkin
+`,
+		"/path/to/helmfile.d/a2.yaml": `
+releases:
+- name: prometheus
+  chart: stable/prometheus
+- name: elasticsearch
+  chart: stable/elasticsearch
+`,
+		"/path/to/helmfile.d/b.yaml": `
+releases:
+- name: grafana
+  chart: stable/grafana
+`,
+	}
+
+	expected := []string{"grafana", "elasticsearch", "prometheus", "zipkin"}
+
+	testcases := []struct {
+		reverse  bool
+		expected []string
+	}{
+		{reverse: false, expected: []string{"zipkin", "prometheus", "elasticsearch", "grafana"}},
+		{reverse: true, expected: []string{"grafana", "elasticsearch", "prometheus", "zipkin"}},
+	}
+	for _, testcase := range testcases {
+		actual := []string{}
+
+		collectReleases := func(st *state.HelmState, helm helmexec.Interface) []error {
+			for _, r := range st.Releases {
+				actual = append(actual, r.Name)
+			}
+			return []error{}
+		}
+		app := appWithFs(&App{
+			KubeContext: "default",
+			Logger:      helmexec.NewLogger(os.Stderr, "debug"),
+			Reverse:     testcase.reverse,
+			Namespace:   "",
+			Selectors:   []string{},
+			Env:         "default",
+		}, files)
+		err := app.VisitDesiredStatesWithReleasesFiltered(
+			"helmfile.yaml", collectReleases,
+		)
+		if err != nil {
+			t.Errorf("unexpected error: %v", err)
+		}
+		if !reflect.DeepEqual(testcase.expected, actual) {
+			t.Errorf("releases did not match: expected=%v actual=%v", expected, actual)
+		}
+	}
+}
+
+func TestLoadDesiredStateFromYaml_DuplicateReleaseName(t *testing.T) {
+	yamlFile := "example/path/to/yaml/file"
+	yamlContent := []byte(`releases:
+- name: myrelease1
+  chart: mychart1
+  labels:
+    stage: pre
+    foo: bar
+- name: myrelease1
+  chart: mychart2
+  labels:
+    stage: post
+`)
+	app := &App{
+		readFile:    ioutil.ReadFile,
+		glob:        filepath.Glob,
+		abs:         filepath.Abs,
+		KubeContext: "default",
+		Logger:      helmexec.NewLogger(os.Stderr, "debug"),
+	}
+	_, err := app.loadDesiredStateFromYaml(yamlContent, yamlFile, "default", "default")
+	if err != nil {
+		t.Error("unexpected error")
+	}
+}

pkg/app/constants.go

@@ -0,0 +1,7 @@
+package app
+
+const (
+	DefaultHelmfile          = "helmfile.yaml"
+	DeprecatedHelmfile       = "charts.yaml"
+	DefaultHelmfileDirectory = "helmfile.d"
+)

pkg/app/context.go

@@ -0,0 +1,33 @@
+package app
+
+import "github.com/roboll/helmfile/state"
+
+type Context struct {
+	updatedRepos map[string]struct{}
+}
+
+func NewContext() Context {
+	return Context{
+		updatedRepos: map[string]struct{}{},
+	}
+}
+
+func (ctx Context) SyncReposOnce(st *state.HelmState, helm state.RepoUpdater) []error {
+	var errs []error
+
+	allUpdated := true
+	for _, r := range st.Repositories {
+		_, exists := ctx.updatedRepos[r.Name]
+		allUpdated = allUpdated && exists
+	}
+
+	if !allUpdated {
+		errs = st.SyncRepos(helm)
+
+		for _, r := range st.Repositories {
+			ctx.updatedRepos[r.Name] = struct{}{}
+		}
+	}
+
+	return errs
+}

pkg/app/errors.go

@@ -0,0 +1,19 @@
+package app
+
+import (
+	"fmt"
+	"strings"
+)
+
+type NoMatchingHelmfileError struct {
+	selectors []string
+	env       string
+}
+
+func (e *NoMatchingHelmfileError) Error() string {
+	return fmt.Sprintf(
+		"err: no releases found that matches specified selector(%s) and environment(%s), in any helmfile",
+		strings.Join(e.selectors, ", "),
+		e.env,
+	)
+}

pkg/app/two_pass_renderer.go

@@ -0,0 +1,80 @@
+package app
+
+import (
+	"bytes"
+	"fmt"
+	"github.com/roboll/helmfile/environment"
+	"github.com/roboll/helmfile/state"
+	"github.com/roboll/helmfile/tmpl"
+	"go.uber.org/zap"
+	"path/filepath"
+	"strings"
+)
+
+func prependLineNumbers(text string) string {
+	buf := bytes.NewBufferString("")
+	lines := strings.Split(text, "\n")
+	for i, line := range lines {
+		buf.WriteString(fmt.Sprintf("%2d: %s\n", i, line))
+	}
+	return buf.String()
+}
+
+type twoPassRenderer struct {
+	reader    func(string) ([]byte, error)
+	env       string
+	namespace string
+	filename  string
+	logger    *zap.SugaredLogger
+	abs       func(string) (string, error)
+}
+
+func (r *twoPassRenderer) renderEnvironment(content []byte) environment.Environment {
+	firstPassEnv := environment.Environment{Name: r.env, Values: map[string]interface{}(nil)}
+	tmplData := state.EnvironmentTemplateData{Environment: firstPassEnv, Namespace: r.namespace}
+	firstPassRenderer := tmpl.NewFirstPassRenderer(filepath.Dir(r.filename), tmplData)
+
+	// parse as much as we can, tolerate errors, this is a preparse
+	yamlBuf, err := firstPassRenderer.RenderTemplateContentToBuffer(content)
+	if err != nil && r.logger != nil {
+		r.logger.Debugf("first-pass rendering input of \"%s\":\n%s", r.filename, prependLineNumbers(string(content)))
+		if yamlBuf == nil { // we have a template syntax error, let the second parse report
+			r.logger.Debugf("template syntax error: %v", err)
+			return firstPassEnv
+		}
+	}
+	c := state.NewCreator(r.logger, r.reader, r.abs)
+	c.Strict = false
+	// create preliminary state, as we may have an environment. Tolerate errors.
+	prestate, err := c.CreateFromYaml(yamlBuf.Bytes(), r.filename, r.env)
+	if err != nil && r.logger != nil {
+		switch err.(type) {
+		case *state.StateLoadError:
+			r.logger.Infof("could not deduce `environment:` block, configuring only .Environment.Name. error: %v", err)
+		}
+		r.logger.Debugf("error in first-pass rendering: result of \"%s\":\n%s", r.filename, prependLineNumbers(yamlBuf.String()))
+	}
+	if prestate != nil {
+		firstPassEnv = prestate.Env
+	}
+	return firstPassEnv
+}
+
+func (r *twoPassRenderer) renderTemplate(content []byte) (*bytes.Buffer, error) {
+	// try a first pass render. This will always succeed, but can produce a limited env
+	firstPassEnv := r.renderEnvironment(content)
+
+	tmplData := state.EnvironmentTemplateData{Environment: firstPassEnv, Namespace: r.namespace}
+	secondPassRenderer := tmpl.NewFileRenderer(r.reader, filepath.Dir(r.filename), tmplData)
+	yamlBuf, err := secondPassRenderer.RenderTemplateContentToBuffer(content)
+	if err != nil {
+		if r.logger != nil {
+			r.logger.Debugf("second-pass rendering failed, input of \"%s\":\n%s", r.filename, prependLineNumbers(string(content)))
+		}
+		return nil, err
+	}
+	if r.logger != nil {
+		r.logger.Debugf("second-pass rendering result of \"%s\":\n%s", r.filename, prependLineNumbers(yamlBuf.String()))
+	}
+	return yamlBuf, nil
+}

pkg/app/two_pass_renderer_test.go

@@ -1,53 +1,24 @@
-package main
+package app
 
 import (
 	"fmt"
-	"io/ioutil"
+	"os"
 	"path/filepath"
 	"strings"
 	"testing"
 
+	"github.com/roboll/helmfile/helmexec"
 	"github.com/roboll/helmfile/state"
 	"gopkg.in/yaml.v2"
 )
 
-// See https://github.com/roboll/helmfile/issues/193
-func TestReadFromYaml_DuplicateReleaseName(t *testing.T) {
-	yamlFile := "example/path/to/yaml/file"
-	yamlContent := []byte(`releases:
-- name: myrelease1
-  chart: mychart1
-  labels:
-    stage: pre
-    foo: bar
-- name: myrelease1
-  chart: mychart2
-  labels:
-    stage: post
-`)
-	app := &app{
-		readFile:    ioutil.ReadFile,
-		glob:        filepath.Glob,
-		abs:         filepath.Abs,
-		kubeContext: "default",
-		logger:      logger,
-	}
-	_, _, err := app.loadDesiredStateFromYaml(yamlContent, yamlFile, "default", []string{}, "default")
-	if err == nil {
-		t.Error("error expected but not happened")
-	}
-	if err.Error() != "duplicate release \"myrelease1\" found: there were 2 releases named \"myrelease1\" matching specified selector" {
-		t.Errorf("unexpected error happened: %v", err)
-	}
-}
-
 func makeRenderer(readFile func(string) ([]byte, error), env string) *twoPassRenderer {
 	return &twoPassRenderer{
 		reader:    readFile,
 		env:       env,
 		namespace: "namespace",
 		filename:  "",
-		logger:    logger,
+		logger:    helmexec.NewLogger(os.Stdout, "debug"),
 		abs:       filepath.Abs,
 	}
 }
@@ -259,3 +230,27 @@ func TestReadFromYaml_RenderTemplateWithNamespace(t *testing.T) {
 		t.Errorf("release name should be namespace-myrelease")
 	}
 }
+
+func TestReadFromYaml_HelfileShouldBeResilentToTemplateErrors(t *testing.T) {
+	yamlContent := []byte(`environments:
+  staging:
+	production:
+
+releases:
+{{ if (eq .Environment.Name "production" }}  # notice syntax error: unclosed left paren
+- name: prod-myrelease
+{{ else }}
+- name: myapp
+{{ end }}
+  chart: mychart
+`)
+	fileReader := func(filename string) ([]byte, error) {
+		return yamlContent, nil
+	}
+
+	r := makeRenderer(fileReader, "staging")
+	_, err := r.renderTemplate(yamlContent)
+	if err == nil {
+		t.Fatalf("wanted error, none returned")
+	}
+}

state/create.go

@@ -6,7 +6,7 @@ import (
 	"github.com/imdario/mergo"
 	"github.com/roboll/helmfile/environment"
 	"github.com/roboll/helmfile/helmexec"
-	"github.com/roboll/helmfile/valuesfile"
+	"github.com/roboll/helmfile/tmpl"
 	"go.uber.org/zap"
 	"gopkg.in/yaml.v2"
 	"io"
@@ -101,6 +101,10 @@ func (c *creator) CreateFromYaml(content []byte, file string, env string) (*Helm
 		state.DeprecatedReleases = []ReleaseSpec{}
 	}
 
+	if state.DeprecatedContext != "" && state.HelmDefaults.KubeContext == "" {
+		state.HelmDefaults.KubeContext = state.DeprecatedContext
+	}
+
 	state.logger = c.logger
 
 	e, err := state.loadEnv(env, c.readFile)
@@ -114,13 +118,14 @@ func (c *creator) CreateFromYaml(content []byte, file string, env string) (*Helm
 	return &state, nil
 }
 
-func (state *HelmState) loadEnv(name string, readFile func(string) ([]byte, error)) (*environment.Environment, error) {
+func (st *HelmState) loadEnv(name string, readFile func(string) ([]byte, error)) (*environment.Environment, error) {
 	envVals := map[string]interface{}{}
-	envSpec, ok := state.Environments[name]
+	envSpec, ok := st.Environments[name]
 	if ok {
 		for _, envvalFile := range envSpec.Values {
-			envvalFullPath := filepath.Join(state.basePath, envvalFile)
-			r := valuesfile.NewRenderer(readFile, filepath.Dir(envvalFullPath), environment.EmptyEnvironment)
+			envvalFullPath := filepath.Join(st.basePath, envvalFile)
+			tmplData := EnvironmentTemplateData{Environment: environment.EmptyEnvironment, Namespace: ""}
+			r := tmpl.NewFileRenderer(readFile, filepath.Dir(envvalFullPath), tmplData)
 			bytes, err := r.RenderToBytes(envvalFullPath)
 			if err != nil {
 				return nil, fmt.Errorf("failed to load environment values file \"%s\": %v", envvalFile, err)
@@ -135,9 +140,9 @@ func (state *HelmState) loadEnv(name string, readFile func(string) ([]byte, erro
 		}
 
 		if len(envSpec.Secrets) > 0 {
-			helm := helmexec.New(state.logger, "")
+			helm := helmexec.New(st.logger, "")
 			for _, secFile := range envSpec.Secrets {
-				path := filepath.Join(state.basePath, secFile)
+				path := filepath.Join(st.basePath, secFile)
 				if _, err := os.Stat(path); os.IsNotExist(err) {
 					return nil, err
 				}

state/release.go

@@ -0,0 +1,69 @@
+package state
+
+import (
+	"fmt"
+	"github.com/roboll/helmfile/tmpl"
+	"gopkg.in/yaml.v2"
+)
+
+func (r ReleaseSpec) ExecuteTemplateExpressions(renderer *tmpl.FileRenderer) (*ReleaseSpec, error) {
+	var result *ReleaseSpec
+	var err error
+
+	result, err = r.Clone()
+	if err != nil {
+		return nil, fmt.Errorf("failed executing template expressions in release \"%s\": %v", r.Name, err)
+	}
+
+	{
+		ts := result.Chart
+		result.Chart, err = renderer.RenderTemplateContentToString([]byte(ts))
+		if err != nil {
+			return nil, fmt.Errorf("failed executing template expressions in release \"%s\".chart = \"%s\": %v", r.Name, ts, err)
+		}
+	}
+
+	{
+		ts := result.Namespace
+		result.Namespace, err = renderer.RenderTemplateContentToString([]byte(ts))
+		if err != nil {
+			return nil, fmt.Errorf("failed executing template expressions in release \"%s\".namespace = \"%s\": %v", r.Name, ts, err)
+		}
+	}
+
+	for i, t := range result.Values {
+		switch ts := t.(type) {
+		case string:
+			s, err := renderer.RenderTemplateContentToBuffer([]byte(ts))
+			if err != nil {
+				return nil, fmt.Errorf("failed executing template expressions in release \"%s\".values[%d] = \"%s\": %v", r.Name, i, ts, err)
+			}
+			result.Values[i] = s.String()
+		}
+	}
+
+	for i, ts := range result.Secrets {
+		s, err := renderer.RenderTemplateContentToBuffer([]byte(ts))
+		if err != nil {
+			return nil, fmt.Errorf("failed executing template expressions in release \"%s\".secrets[%d] = \"%s\": %v", r.Name, i, ts, err)
+		}
+		result.Secrets[i] = s.String()
+	}
+
+	return result, nil
+}
+
+func (r ReleaseSpec) Clone() (*ReleaseSpec, error) {
+	serialized, err := yaml.Marshal(r)
+	if err != nil {
+		return nil, fmt.Errorf("failed cloning release \"%s\": %v", r.Name, err)
+	}
+
+	var deserialized ReleaseSpec
+
+	if err := yaml.Unmarshal(serialized, &deserialized); err != nil {
+		return nil, fmt.Errorf("failed cloning release \"%s\": %v", r.Name, err)
+	}
+
+	return &deserialized, nil
+}

state/state_exec_tmpl.go

@@ -0,0 +1,32 @@
+package state
+
+import (
+	"fmt"
+	"github.com/roboll/helmfile/tmpl"
+)
+
+func (st *HelmState) envTemplateData() EnvironmentTemplateData {
+	return EnvironmentTemplateData{
+		st.Env,
+		st.Namespace,
+	}
+}
+
+func (st *HelmState) ExecuteTemplates() (*HelmState, error) {
+	r := *st
+
+	for i, rt := range st.Releases {
+		tmplData := ReleaseTemplateData{
+			Environment: st.Env,
+			Release:     rt,
+		}
+		renderer := tmpl.NewFileRenderer(st.readFile, st.basePath, tmplData)
+		r, err := rt.ExecuteTemplateExpressions(renderer)
+		if err != nil {
+			return nil, fmt.Errorf("failed executing templates in release \"%s\".\"%s\": %v", st.FilePath, rt.Name, err)
+		}
+		st.Releases[i] = *r
+	}
+
+	return &r, nil
+}

state/state_exec_tmpl_test.go

@@ -0,0 +1,76 @@
+package state
+
+import (
+	"reflect"
+	"testing"
+
+	"github.com/roboll/helmfile/environment"
+)
+
+func TestHelmState_executeTemplates(t *testing.T) {
+	tests := []struct {
+		name  string
+		input ReleaseSpec
+		want  ReleaseSpec
+	}{
+		{
+			name: "Has template expressions in chart, values, and secrets",
+			input: ReleaseSpec{
+				Chart:     "test-charts/{{ .Release.Name }}",
+				Version:   "0.1",
+				Verify:    nil,
+				Name:      "test-app",
+				Namespace: "test-namespace-{{ .Release.Name }}",
+				Values:    []interface{}{"config/{{ .Environment.Name }}/{{ .Release.Name }}/values.yaml"},
+				Secrets:   []string{"config/{{ .Environment.Name }}/{{ .Release.Name }}/secrets.yaml"},
+			},
+			want: ReleaseSpec{
+				Chart:     "test-charts/test-app",
+				Version:   "0.1",
+				Verify:    nil,
+				Name:      "test-app",
+				Namespace: "test-namespace-test-app",
+				Values:    []interface{}{"config/test_env/test-app/values.yaml"},
+				Secrets:   []string{"config/test_env/test-app/secrets.yaml"},
+			},
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			state := &HelmState{
+				basePath: ".",
+				HelmDefaults: HelmSpec{
+					KubeContext: "test_context",
+				},
+				Env:          environment.Environment{Name: "test_env"},
+				Namespace:    "test-namespace_",
+				Repositories: nil,
+				Releases: []ReleaseSpec{
+					tt.input,
+				},
+			}
+
+			r, err := state.ExecuteTemplates()
+			if err != nil {
+				t.Errorf("Unexpected error: %v", err)
+				t.FailNow()
+			}
+
+			actual := r.Releases[0]
+
+			if !reflect.DeepEqual(actual.Chart, tt.want.Chart) {
+				t.Errorf("expected %+v, got %+v", tt.want.Chart, actual.Chart)
+			}
+			if !reflect.DeepEqual(actual.Namespace, tt.want.Namespace) {
+				t.Errorf("expected %+v, got %+v", tt.want.Namespace, actual.Namespace)
+			}
+			if !reflect.DeepEqual(actual.Values, tt.want.Values) {
+				t.Errorf("expected %+v, got %+v", tt.want.Values, actual.Values)
+			}
+			if !reflect.DeepEqual(actual.Secrets, tt.want.Secrets) {
+				t.Errorf("expected %+v, got %+v", tt.want.Secrets, actual.Secrets)
+			}
+		})
+	}
+}

state/state_run.go

@@ -0,0 +1,88 @@
+package state
+
+import (
+	"fmt"
+	"github.com/roboll/helmfile/helmexec"
+	"sync"
+)
+
+type result struct {
+	release ReleaseSpec
+	err     error
+}
+
+func (st *HelmState) scatterGather(concurrency int, items int, produceInputs func(), receiveInputsAndProduceIntermediates func(int), aggregateIntermediates func()) {
+	numReleases := len(st.Releases)
+	if concurrency < 1 {
+		concurrency = numReleases
+	} else if concurrency > numReleases {
+		concurrency = numReleases
+	}
+
+	// WaitGroup is required to wait until goroutine per job in job queue cleanly stops.
+	var waitGroup sync.WaitGroup
+	waitGroup.Add(concurrency)
+
+	go produceInputs()
+
+	for w := 1; w <= concurrency; w++ {
+		go func(id int) {
+			st.logger.Debugf("worker %d/%d started", id, concurrency)
+			receiveInputsAndProduceIntermediates(id)
+			st.logger.Debugf("worker %d/%d finished", id, concurrency)
+			waitGroup.Done()
+		}(w)
+	}
+
+	aggregateIntermediates()
+
+	// Wait until all the goroutines to gracefully finish
+	waitGroup.Wait()
+}
+
+func (st *HelmState) scatterGatherReleases(helm helmexec.Interface, concurrency int, do func(ReleaseSpec) error) []error {
+	var errs []error
+
+	inputs := st.Releases
+	inputsSize := len(inputs)
+
+	releases := make(chan ReleaseSpec)
+	results := make(chan result)
+
+	st.scatterGather(
+		concurrency,
+		inputsSize,
+		func() {
+			for _, release := range inputs {
+				releases <- release
+			}
+			close(releases)
+		},
+		func(id int) {
+			for release := range releases {
+				err := do(release)
+				st.logger.Debugf("sending result for release: %s\n", release.Name)
+				results <- result{release: release, err: err}
+				st.logger.Debugf("sent result for release: %s\n", release.Name)
+			}
+		},
+		func() {
+			for i := range inputs {
+				st.logger.Debugf("receiving result %d", i)
+				r := <-results
+				if r.err != nil {
+					errs = append(errs, fmt.Errorf("release \"%s\" failed: %v", r.release.Name, r.err))
+				} else {
+					st.logger.Debugf("received result for release \"%s\"", r.release.Name)
+				}
+				st.logger.Debugf("received result for %d", i)
+			}
+		},
+	)
+
+	if len(errs) != 0 {
+		return errs
+	}
+
+	return nil
+}

state/state_test.go

@@ -116,7 +116,7 @@ func TestHelmState_applyDefaultsTo(t *testing.T) {
 		t.Run(tt.name, func(t *testing.T) {
 			state := &HelmState{
 				basePath:           tt.fields.BaseChartPath,
-				Context:            tt.fields.Context,
+				DeprecatedContext:  tt.fields.Context,
 				DeprecatedReleases: tt.fields.DeprecatedReleases,
 				Namespace:          tt.fields.Namespace,
 				Repositories:       tt.fields.Repositories,
@@ -192,7 +192,6 @@ func TestHelmState_flagsForUpgrade(t *testing.T) {
 			},
 			want: []string{
 				"--version", "0.1",
-				"--verify",
 				"--namespace", "test-namespace",
 			},
 		},
@@ -228,7 +227,6 @@ func TestHelmState_flagsForUpgrade(t *testing.T) {
 			},
 			want: []string{
 				"--version", "0.1",
-				"--force",
 				"--namespace", "test-namespace",
 			},
 		},
@@ -264,7 +262,6 @@ func TestHelmState_flagsForUpgrade(t *testing.T) {
 			},
 			want: []string{
 				"--version", "0.1",
-				"--recreate-pods",
 				"--namespace", "test-namespace",
 			},
 		},
@@ -336,7 +333,6 @@ func TestHelmState_flagsForUpgrade(t *testing.T) {
 			},
 			want: []string{
 				"--version", "0.1",
-				"--wait",
 				"--namespace", "test-namespace",
 			},
 		},
@@ -376,14 +372,66 @@ func TestHelmState_flagsForUpgrade(t *testing.T) {
 				"--namespace", "test-namespace",
 			},
 		},
+		{
+			name: "atomic",
+			defaults: HelmSpec{
+				Atomic: false,
+			},
+			release: &ReleaseSpec{
+				Chart:     "test/chart",
+				Version:   "0.1",
+				Atomic:    &enable,
+				Name:      "test-charts",
+				Namespace: "test-namespace",
+			},
+			want: []string{
+				"--version", "0.1",
+				"--atomic",
+				"--namespace", "test-namespace",
+			},
+		},
+		{
+			name: "atomic-override-default",
+			defaults: HelmSpec{
+				Atomic: true,
+			},
+			release: &ReleaseSpec{
+				Chart:     "test/chart",
+				Version:   "0.1",
+				Atomic:    &disable,
+				Name:      "test-charts",
+				Namespace: "test-namespace",
+			},
+			want: []string{
+				"--version", "0.1",
+				"--namespace", "test-namespace",
+			},
+		},
+		{
+			name: "atomic-from-default",
+			defaults: HelmSpec{
+				Atomic: true,
+			},
+			release: &ReleaseSpec{
+				Chart:     "test/chart",
+				Version:   "0.1",
+				Name:      "test-charts",
+				Namespace: "test-namespace",
+			},
+			want: []string{
+				"--version", "0.1",
+				"--atomic",
+				"--namespace", "test-namespace",
+			},
+		},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
 			state := &HelmState{
-				basePath:     "./",
-				Context:      "default",
-				Releases:     []ReleaseSpec{*tt.release},
-				HelmDefaults: tt.defaults,
+				basePath:          "./",
+				DeprecatedContext: "default",
+				Releases:          []ReleaseSpec{*tt.release},
+				HelmDefaults:      tt.defaults,
 			}
 			helm := helmexec.New(logger, "default")
 			args, err := state.flagsForUpgrade(helm, tt.release)
@@ -524,6 +572,14 @@ func (helm *mockHelmExec) UpdateDeps(chart string) error {
 	return nil
 }
 
+func (helm *mockHelmExec) BuildDeps(chart string) error {
+	if strings.Contains(chart, "error") {
+		return errors.New("error")
+	}
+	helm.charts = append(helm.charts, chart)
+	return nil
+}
+
 func (helm *mockHelmExec) SetExtraArgs(args ...string) {
 	return
 }
@@ -558,6 +614,9 @@ func (helm *mockHelmExec) ReleaseStatus(release string) error {
 func (helm *mockHelmExec) DeleteRelease(name string, flags ...string) error {
 	return nil
 }
+func (helm *mockHelmExec) List(filter string) (string, error) {
+	return "", nil
+}
 func (helm *mockHelmExec) DecryptSecret(name string) (string, error) {
 	return "", nil
 }
@@ -738,6 +797,7 @@ func TestHelmState_SyncReleases(t *testing.T) {
 		t.Run(tt.name, func(t *testing.T) {
 			state := &HelmState{
 				Releases: tt.releases,
+				logger:   logger,
 			}
 			if _ = state.SyncReleases(tt.helm, []string{}, 1); !reflect.DeepEqual(tt.helm.releases, tt.wantReleases) {
 				t.Errorf("HelmState.SyncReleases() for [%s] = %v, want %v", tt.name, tt.helm.releases, tt.wantReleases)
@@ -815,6 +875,7 @@ func TestHelmState_ReleaseStatuses(t *testing.T) {
 		i := func(t *testing.T) {
 			state := &HelmState{
 				Releases: tt.releases,
+				logger:   logger,
 			}
 			errs := state.ReleaseStatuses(tt.helm, 1)
 			if (errs != nil) != tt.wantErr {
@@ -874,8 +935,9 @@ func TestHelmState_TestReleasesNoCleanUp(t *testing.T) {
 		i := func(t *testing.T) {
 			state := &HelmState{
 				Releases: tt.releases,
+				logger:   logger,
 			}
-			errs := state.TestReleases(tt.helm, tt.cleanup, 1)
+			errs := state.TestReleases(tt.helm, tt.cleanup, 1, 1)
 			if (errs != nil) != tt.wantErr {
 				t.Errorf("TestReleases() for %s error = %v, wantErr %v", tt.name, errs, tt.wantErr)
 				return

state/types.go

@@ -0,0 +1,24 @@
+package state
+
+import "github.com/roboll/helmfile/environment"
+
+// TemplateSpec defines the structure of a reusable and composable template for helm releases.
+type TemplateSpec struct {
+	ReleaseSpec `yaml:",inline"`
+}
+
+// EnvironmentTemplateData provides variables accessible while executing golang text/template expressions in helmfile and values YAML files
+type EnvironmentTemplateData struct {
+	// Environment is accessible as `.Environment` from any template executed by the renderer
+	Environment environment.Environment
+	// Namespace is accessible as `.Namespace` from any non-values template executed by the renderer
+	Namespace string
+}
+
+// ReleaseTemplateData provides variables accessible while executing golang text/template expressions in releases of a helmfile YAML file
+type ReleaseTemplateData struct {
+	// Environment is accessible as `.Environment` from any template expression executed by the renderer
+	Environment environment.Environment
+	// Release is accessible as `.Release` from any template expression executed by the renderer
+	Release ReleaseSpec
+}

test/integration/happypath.yaml

@@ -2,7 +2,8 @@ repositories:
   - name: stable
     url: https://kubernetes-charts.storage.googleapis.com/
 
-context: minikube
+helmDefaults:
+  kubeContext: minikube
 
 releases:
 

test/integration/run.sh

@@ -47,6 +47,7 @@ set -e
 info "Using namespace: ${test_ns}"
 info "Using Helm version: $(helm version --short --client | grep -o v.*$)"
 ${helm} init --wait --override spec.template.spec.automountServiceAccountToken=true
+${helm} plugin install https://github.com/databus23/helm-diff --version master
 ${kubectl} get namespace ${test_ns} &> /dev/null && warn "Namespace ${test_ns} exists, from a previous test run?"
 $kubectl create namespace ${test_ns} || fail "Could not create namespace ${test_ns}"
 trap "{ $kubectl delete namespace ${test_ns}; }" EXIT # remove namespace whenever we exit this script
@@ -55,14 +56,33 @@ trap "{ $kubectl delete namespace ${test_ns}; }" EXIT # remove namespace wheneve
 # TEST CASES----------------------------------------------------------------------------------------------------------
 
 test_start "happypath - simple rollout of httpbin chart"
+
+info "Diffing ${dir}/happypath.yaml"
+bash -c "${helmfile} -f ${dir}/happypath.yaml diff --detailed-exitcode; code="'$?'"; [ "'${code}'" -eq 2 ]" || fail "unexpected exit code returned by helmfile diff"
+
+info "Templating ${dir}/happypath.yaml"
+${helmfile} -f ${dir}/happypath.yaml template
+code=$?
+[ ${code} -eq 0 ] || fail "unexpected exit code returned by helmfile template: ${code}"
+
 info "Syncing ${dir}/happypath.yaml"
 ${helmfile} -f ${dir}/happypath.yaml sync
 wait_deploy_ready httpbin-httpbin
 retry 5 "curl --fail $(minikube service --url --namespace=${test_ns} httpbin-httpbin)/status/200"
 [ ${retry_result} -eq 0 ] || fail "httpbin failed to return 200 OK"
+
+info "Applying ${dir}/happypath.yaml"
+${helmfile} -f ${dir}/happypath.yaml apply
+code=$?
+[ ${code} -eq 0 ] || fail "unexpected exit code returned by helmfile apply: ${code}"
+
 info "Deleting release"
-${helmfile} -f ${dir}/happypath.yaml delete --auto-approve
+${helmfile} -f ${dir}/happypath.yaml delete
 ${helm} status --namespace=${test_ns} httpbin &> /dev/null && fail "release should not exist anymore after a delete"
+
+info "Ensuring \"helmfile delete\" doesn't fail when no releases installed"
+${helmfile} -f ${dir}/happypath.yaml delete || fail "\"helmfile delete\" shouldn't fail when there are no installed releases"
+
 test_pass "happypath"
 
 

tmpl/context_funcs.go

@@ -22,6 +22,9 @@ func (c *Context) createFuncMap() template.FuncMap {
 		"fromYaml":       FromYaml,
 		"setValueAtPath": SetValueAtPath,
 		"requiredEnv":    RequiredEnv,
+		"get":            get,
+		"getOrNil":       getOrNil,
+		"tpl":            c.Tpl,
 	}
 	if c.preRender {
 		// disable potential side-effect template calls
@@ -112,7 +115,12 @@ func (c *Context) Exec(command string, args []interface{}, inputs ...string) (st
 }
 
 func (c *Context) ReadFile(filename string) (string, error) {
-	path := filepath.Join(c.basePath, filename)
+	var path string
+	if filepath.IsAbs(filename) {
+		path = filename
+	} else {
+		path = filepath.Join(c.basePath, filename)
+	}
 
 	bytes, err := c.readFile(path)
 	if err != nil {
@@ -121,6 +129,14 @@ func (c *Context) ReadFile(filename string) (string, error) {
 	return string(bytes), nil
 }
 
+func (c *Context) Tpl(text string, data interface{}) (string, error) {
+	buf, err := c.RenderTemplateToBuffer(text, data)
+	if err != nil {
+		return "", err
+	}
+	return buf.String(), nil
+}
+
 func ToYaml(v interface{}) (string, error) {
 	data, err := yaml.Marshal(v)
 	if err != nil {

tmpl/context_funcs_test.go

@@ -2,6 +2,7 @@ package tmpl
 
 import (
 	"fmt"
+	"path/filepath"
 	"reflect"
 	"testing"
 )
@@ -11,7 +12,27 @@ func TestReadFile(t *testing.T) {
   bar: BAR
 `
 	expectedFilename := "values.yaml"
-	ctx := &Context{readFile: func(filename string) ([]byte, error) {
+	ctx := &Context{basePath: ".", readFile: func(filename string) ([]byte, error) {
+		if filename != expectedFilename {
+			return nil, fmt.Errorf("unexpected filename: expected=%v, actual=%s", expectedFilename, filename)
+		}
+		return []byte(expected), nil
+	}}
+	actual, err := ctx.ReadFile(expectedFilename)
+	if err != nil {
+		t.Errorf("unexpected error: %v", err)
+	}
+	if !reflect.DeepEqual(actual, expected) {
+		t.Errorf("unexpected result: expected=%v, actual=%v", expected, actual)
+	}
+}
+
+func TestReadFile_PassAbsPath(t *testing.T) {
+	expected := `foo:
+  bar: BAR
+`
+	expectedFilename, _ := filepath.Abs("values.yaml")
+	ctx := &Context{basePath: ".", readFile: func(filename string) ([]byte, error) {
 		if filename != expectedFilename {
 			return nil, fmt.Errorf("unexpected filename: expected=%v, actual=%s", expectedFilename, filename)
 		}
@@ -97,3 +118,18 @@ func TestSetValueAtPath_TwoComponents(t *testing.T) {
 		t.Errorf("unexpected result: expected=%v, actual=%v", expected, actual)
 	}
 }
+
+func TestTpl(t *testing.T) {
+	text := `foo: {{ .foo }}
+`
+	expected := `foo: FOO
+`
+	ctx := &Context{basePath: "."}
+	actual, err := ctx.Tpl(text, map[string]interface{}{"foo": "FOO"})
+	if err != nil {
+		t.Errorf("unexpected error: %v", err)
+	}
+	if !reflect.DeepEqual(actual, expected) {
+		t.Errorf("unexpected result: expected=%v, actual=%v", expected, actual)
+	}
+}

tmpl/context_tmpl_test.go

@@ -60,11 +60,61 @@ func TestRenderTemplate_WithData(t *testing.T) {
 	}
 }
 
-func renderTemplateToString(s string) (string, error) {
+func TestRenderTemplate_AccessingMissingKeyWithGetOrNil(t *testing.T) {
+	valuesYamlContent := `foo:
+  bar: {{ . | getOrNil "foo.bar" }}
+`
+	expected := `foo:
+  bar: <no value>
+`
+	expectedFilename := "values.yaml"
+	data := map[string]interface{}{}
+	ctx := &Context{readFile: func(filename string) ([]byte, error) {
+		if filename != expectedFilename {
+			return nil, fmt.Errorf("unexpected filename: expected=%v, actual=%s", expectedFilename, filename)
+		}
+		return []byte(valuesYamlContent), nil
+	}}
+	buf, err := ctx.RenderTemplateToBuffer(valuesYamlContent, data)
+	if err != nil {
+		t.Errorf("unexpected error: %v", err)
+	}
+	actual := buf.String()
+	if !reflect.DeepEqual(actual, expected) {
+		t.Errorf("unexpected result: expected=%v, actual=%v", expected, actual)
+	}
+}
+
+func TestRenderTemplate_Defaulting(t *testing.T) {
+	valuesYamlContent := `foo:
+  bar: {{ . | getOrNil "foo.bar" | default "DEFAULT" }}
+`
+	expected := `foo:
+  bar: DEFAULT
+`
+	expectedFilename := "values.yaml"
+	data := map[string]interface{}{}
+	ctx := &Context{readFile: func(filename string) ([]byte, error) {
+		if filename != expectedFilename {
+			return nil, fmt.Errorf("unexpected filename: expected=%v, actual=%s", expectedFilename, filename)
+		}
+		return []byte(valuesYamlContent), nil
+	}}
+	buf, err := ctx.RenderTemplateToBuffer(valuesYamlContent, data)
+	if err != nil {
+		t.Errorf("unexpected error: %v", err)
+	}
+	actual := buf.String()
+	if !reflect.DeepEqual(actual, expected) {
+		t.Errorf("unexpected result: expected=%v, actual=%v", expected, actual)
+	}
+}
+
+func renderTemplateToString(s string, data ...interface{}) (string, error) {
 	ctx := &Context{readFile: func(filename string) ([]byte, error) {
 		return nil, fmt.Errorf("unexpected call to readFile: filename=%s", filename)
 	}}
-	tplString, err := ctx.RenderTemplateToBuffer(s)
+	tplString, err := ctx.RenderTemplateToBuffer(s, data...)
 	if err != nil {
 		return "", err
 	}
@@ -75,6 +125,7 @@ func Test_renderTemplateToString(t *testing.T) {
 	type args struct {
 		s    string
 		envs map[string]string
+		data interface{}
 	}
 	tests := []struct {
 		name    string
@@ -127,6 +178,18 @@ func Test_renderTemplateToString(t *testing.T) {
 			want:    "7",
 			wantErr: false,
 		},
+		{
+			name: "get",
+			args: args{
+				s:    `{{ . | get "Foo" }}, {{ . | get "Bar" "2" }}`,
+				envs: map[string]string{},
+				data: map[string]interface{}{
+					"Foo": "1",
+				},
+			},
+			want:    "1, 2",
+			wantErr: false,
+		},
 		{
 			name: "env var not set",
 			args: args{
@@ -175,7 +238,7 @@ func Test_renderTemplateToString(t *testing.T) {
 					t.Error("renderTemplateToString() could not set env var for testing")
 				}
 			}
-			got, err := renderTemplateToString(tt.args.s)
+			got, err := renderTemplateToString(tt.args.s, tt.args.data)
 			if (err != nil) != tt.wantErr {
 				t.Errorf("renderTemplateToString() for %s error = %v, wantErr %v", tt.name, err, tt.wantErr)
 				return

tmpl/file.go

@@ -1,66 +0,0 @@
-package tmpl
-
-import (
-	"bytes"
-	"io/ioutil"
-
-	"github.com/roboll/helmfile/environment"
-)
-
-type templateFileRenderer struct {
-	ReadFile func(string) ([]byte, error)
-	Context  *Context
-	Data     TemplateData
-}
-
-type TemplateData struct {
-	// Environment is accessible as `.Environment` from any template executed by the renderer
-	Environment environment.Environment
-	// Namespace is accessible as `.Namespace` from any non-values template executed by the renderer
-	Namespace string
-}
-
-type FileRenderer interface {
-	RenderTemplateFileToBuffer(file string) (*bytes.Buffer, error)
-}
-
-func NewFileRenderer(readFile func(filename string) ([]byte, error), basePath string, env environment.Environment, namespace string) *templateFileRenderer {
-	return &templateFileRenderer{
-		ReadFile: readFile,
-		Context: &Context{
-			basePath: basePath,
-			readFile: readFile,
-		},
-		Data: TemplateData{
-			Environment: env,
-			Namespace:   namespace,
-		},
-	}
-}
-
-func NewFirstPassRenderer(basePath string, env environment.Environment) *templateFileRenderer {
-	return &templateFileRenderer{
-		ReadFile: ioutil.ReadFile,
-		Context: &Context{
-			preRender: true,
-			basePath:  basePath,
-			readFile:  ioutil.ReadFile,
-		},
-		Data: TemplateData{
-			Environment: env,
-		},
-	}
-}
-
-func (r *templateFileRenderer) RenderTemplateFileToBuffer(file string) (*bytes.Buffer, error) {
-	content, err := r.ReadFile(file)
-	if err != nil {
-		return nil, err
-	}
-
-	return r.RenderTemplateContentToBuffer(content)
-}
-
-func (r *templateFileRenderer) RenderTemplateContentToBuffer(content []byte) (*bytes.Buffer, error) {
-	return r.Context.RenderTemplateToBuffer(string(content), r.Data)
-}

tmpl/file_renderer.go

@@ -0,0 +1,78 @@
+package tmpl
+
+import (
+	"bytes"
+	"io/ioutil"
+
+	"fmt"
+	"strings"
+)
+
+type FileRenderer struct {
+	ReadFile func(string) ([]byte, error)
+	Context  *Context
+	Data     interface{}
+}
+
+func NewFileRenderer(readFile func(filename string) ([]byte, error), basePath string, data interface{}) *FileRenderer {
+	return &FileRenderer{
+		ReadFile: readFile,
+		Context: &Context{
+			basePath: basePath,
+			readFile: readFile,
+		},
+		Data: data,
+	}
+}
+
+func NewFirstPassRenderer(basePath string, data interface{}) *FileRenderer {
+	return &FileRenderer{
+		ReadFile: ioutil.ReadFile,
+		Context: &Context{
+			preRender: true,
+			basePath:  basePath,
+			readFile:  ioutil.ReadFile,
+		},
+		Data: data,
+	}
+}
+
+func (r *FileRenderer) RenderTemplateFileToBuffer(file string) (*bytes.Buffer, error) {
+	content, err := r.ReadFile(file)
+	if err != nil {
+		return nil, err
+	}
+
+	return r.RenderTemplateContentToBuffer(content)
+}
+
+func (r *FileRenderer) RenderToBytes(path string) ([]byte, error) {
+	var yamlBytes []byte
+	splits := strings.Split(path, ".")
+	if len(splits) > 0 && splits[len(splits)-1] == "gotmpl" {
+		yamlBuf, err := r.RenderTemplateFileToBuffer(path)
+		if err != nil {
+			return nil, fmt.Errorf("failed to render [%s], because of %v", path, err)
+		}
+		yamlBytes = yamlBuf.Bytes()
+	} else {
+		var err error
+		yamlBytes, err = r.ReadFile(path)
+		if err != nil {
+			return nil, fmt.Errorf("failed to load [%s]: %v", path, err)
+		}
+	}
+	return yamlBytes, nil
+}
+
+func (r *FileRenderer) RenderTemplateContentToBuffer(content []byte) (*bytes.Buffer, error) {
+	return r.Context.RenderTemplateToBuffer(string(content), r.Data)
+}
+
+func (r *FileRenderer) RenderTemplateContentToString(content []byte) (string, error) {
+	buf, err := r.Context.RenderTemplateToBuffer(string(content), r.Data)
+	if err != nil {
+		return "", err
+	}
+	return buf.String(), nil
+}

tmpl/file_renderer_test.go

@@ -1,4 +1,4 @@
-package valuesfile
+package tmpl
 
 import (
 	"fmt"
@@ -7,6 +7,11 @@ import (
 	"testing"
 )
 
+var emptyEnvTmplData = map[string]interface{}{
+	"Environment": environment.EmptyEnvironment,
+	"Namespace":   "",
+}
+
 func TestRenderToBytes_Gotmpl(t *testing.T) {
 	valuesYamlTmplContent := `foo:
   bar: '{{ readFile "data.txt" }}'
@@ -17,7 +22,7 @@ func TestRenderToBytes_Gotmpl(t *testing.T) {
 `
 	dataFile := "data.txt"
 	valuesTmplFile := "values.yaml.gotmpl"
-	r := NewRenderer(func(filename string) ([]byte, error) {
+	r := NewFileRenderer(func(filename string) ([]byte, error) {
 		switch filename {
 		case valuesTmplFile:
 			return []byte(valuesYamlTmplContent), nil
@@ -25,7 +30,7 @@ func TestRenderToBytes_Gotmpl(t *testing.T) {
 			return []byte(dataFileContent), nil
 		}
 		return nil, fmt.Errorf("unexpected filename: expected=%v or %v, actual=%s", dataFile, valuesTmplFile, filename)
-	}, "", environment.EmptyEnvironment)
+	}, "", emptyEnvTmplData)
 	buf, err := r.RenderToBytes(valuesTmplFile)
 	if err != nil {
 		t.Errorf("unexpected error: %v", err)
@@ -44,13 +49,13 @@ func TestRenderToBytes_Yaml(t *testing.T) {
   bar: '{{ readFile "data.txt" }}'
 `
 	valuesFile := "values.yaml"
-	r := NewRenderer(func(filename string) ([]byte, error) {
+	r := NewFileRenderer(func(filename string) ([]byte, error) {
 		switch filename {
 		case valuesFile:
 			return []byte(valuesYamlContent), nil
 		}
 		return nil, fmt.Errorf("unexpected filename: expected=%v, actual=%s", valuesFile, filename)
-	}, "", environment.EmptyEnvironment)
+	}, "", emptyEnvTmplData)
 	buf, err := r.RenderToBytes(valuesFile)
 	if err != nil {
 		t.Errorf("unexpected error: %v", err)

tmpl/get_or_nil.go

@@ -0,0 +1,91 @@
+package tmpl
+
+import (
+	"fmt"
+	"reflect"
+	"strings"
+)
+
+type noValueError struct {
+	msg string
+}
+
+func (e *noValueError) Error() string {
+	return e.msg
+}
+
+func get(path string, varArgs ...interface{}) (interface{}, error) {
+	var defSet bool
+	var def interface{}
+	var obj interface{}
+	switch len(varArgs) {
+	case 1:
+		defSet = false
+		def = nil
+		obj = varArgs[0]
+	case 2:
+		defSet = true
+		def = varArgs[0]
+		obj = varArgs[1]
+	default:
+		return nil, fmt.Errorf("unexpected number of args pased to the template function get(path, [def, ]obj): expected 1 or 2, got %d, args was %v", len(varArgs), varArgs)
+	}
+
+	if path == "" {
+		return obj, nil
+	}
+	keys := strings.Split(path, ".")
+	var v interface{}
+	var ok bool
+	switch typedObj := obj.(type) {
+	case map[string]interface{}:
+		v, ok = typedObj[keys[0]]
+		if !ok {
+			if defSet {
+				return def, nil
+			}
+			return nil, &noValueError{fmt.Sprintf("no value exist for key \"%s\" in %v", keys[0], typedObj)}
+		}
+	case map[interface{}]interface{}:
+		v, ok = typedObj[keys[0]]
+		if !ok {
+			if defSet {
+				return def, nil
+			}
+			return nil, &noValueError{fmt.Sprintf("no value exist for key \"%s\" in %v", keys[0], typedObj)}
+		}
+	default:
+		maybeStruct := reflect.ValueOf(typedObj)
+		if maybeStruct.Kind() != reflect.Struct {
+			return nil, &noValueError{fmt.Sprintf("unexpected type(%v) of value for key \"%s\": it must be either map[string]interface{} or any struct", reflect.TypeOf(obj), keys[0])}
+		} else if maybeStruct.NumField() < 1 {
+			return nil, &noValueError{fmt.Sprintf("no accessible struct fields for key \"%s\"", keys[0])}
+		}
+		f := maybeStruct.FieldByName(keys[0])
+		if !f.IsValid() {
+			if defSet {
+				return def, nil
+			}
+			return nil, &noValueError{fmt.Sprintf("no field named \"%s\" exist in %v", keys[0], typedObj)}
+		}
+		v = f.Interface()
+	}
+
+	if defSet {
+		return get(strings.Join(keys[1:], "."), def, v)
+	}
+	return get(strings.Join(keys[1:], "."), v)
+}
+
+func getOrNil(path string, o interface{}) (interface{}, error) {
+	v, err := get(path, o)
+	if err != nil {
+		switch err.(type) {
+		case *noValueError:
+			return nil, nil
+		default:
+			return nil, err
+		}
+	}
+	return v, nil
+}

tmpl/get_or_nil_test.go

@@ -0,0 +1,128 @@
+package tmpl
+
+import (
+	"testing"
+)
+
+type EmptyStruct struct {
+}
+
+func TestGetStruct(t *testing.T) {
+	type Foo struct{ Bar string }
+
+	obj := struct{ Foo }{Foo{Bar: "Bar"}}
+
+	v1, err := get("Foo.Bar", obj)
+
+	if err != nil {
+		t.Errorf("unexpected error: %v", err)
+	}
+	if v1 != "Bar" {
+		t.Errorf("unexpected value for path Foo.Bar in %v: expected=Bar, actual=%v", obj, v1)
+	}
+
+	_, err = get("Foo.baz", obj)
+
+	if err == nil {
+		t.Errorf("expected error but was not occurred")
+	}
+
+	_, err = get("foo", EmptyStruct{})
+
+	if err == nil {
+		t.Errorf("expected error but was not occurred")
+	}
+}
+
+func TestGetMap(t *testing.T) {
+	obj := map[string]interface{}{"Foo": map[string]interface{}{"Bar": "Bar"}}
+
+	v1, err := get("Foo.Bar", obj)
+
+	if err != nil {
+		t.Errorf("unexpected error: %v", err)
+	}
+	if v1 != "Bar" {
+		t.Errorf("unexpected value for path Foo.Bar in %v: expected=Bar, actual=%v", obj, v1)
+	}
+
+	_, err = get("Foo.baz", obj)
+
+	if err == nil {
+		t.Errorf("expected error but was not occurred")
+	}
+}
+
+func TestGet_Default(t *testing.T) {
+	obj := map[string]interface{}{"Foo": map[string]interface{}{}, "foo": 1}
+
+	v1, err := get("Foo.Bar", "Bar", obj)
+
+	if err != nil {
+		t.Errorf("unexpected error: %v", err)
+	}
+	if v1 != "Bar" {
+		t.Errorf("unexpected value for path Foo.Bar in %v: expected=Bar, actual=%v", obj, v1)
+	}
+
+	v2, err := get("Baz", "Baz", obj)
+
+	if err != nil {
+		t.Errorf("unexpected error: %v", err)
+	}
+	if v2 != "Baz" {
+		t.Errorf("unexpected value for path Baz in %v: expected=Baz, actual=%v", obj, v2)
+	}
+
+	_, err = get("foo.Bar", "fooBar", obj)
+
+	if err == nil {
+		t.Errorf("expected error but was not occurred")
+	}
+}
+
+func TestGetOrNilStruct(t *testing.T) {
+	type Foo struct{ Bar string }
+
+	obj := struct{ Foo }{Foo{Bar: "Bar"}}
+
+	v1, err := getOrNil("Foo.Bar", obj)
+
+	if err != nil {
+		t.Errorf("unexpected error: %v", err)
+	}
+	if v1 != "Bar" {
+		t.Errorf("unexpected value for path Foo.Bar in %v: expected=Bar, actual=%v", obj, v1)
+	}
+
+	v2, err := getOrNil("Foo.baz", obj)
+
+	if err != nil {
+		t.Errorf("unexpected error: %v", err)
+	}
+	if v2 != nil {
+		t.Errorf("unexpected value for path Foo.baz in %v: expected=nil, actual=%v", obj, v2)
+	}
+}
+
+func TestGetOrNilMap(t *testing.T) {
+	obj := map[string]interface{}{"Foo": map[string]interface{}{"Bar": "Bar"}}
+
+	v1, err := getOrNil("Foo.Bar", obj)
+
+	if err != nil {
+		t.Errorf("unexpected error: %v", err)
+	}
+	if v1 != "Bar" {
+		t.Errorf("unexpected value for path Foo.Bar in %v: expected=Bar, actual=%v", obj, v1)
+	}
+
+	v2, err := getOrNil("Foo.baz", obj)
+
+	if err != nil {
+		t.Errorf("unexpected error: %v", err)
+	}
+	if v2 != nil {
+		t.Errorf("unexpected value for path Foo.baz in %v: expected=nil, actual=%v", obj, v2)
+	}
+}

tmpl/text_renderer.go

@@ -0,0 +1,30 @@
+package tmpl
+
+type templateTextRenderer struct {
+	ReadText func(string) ([]byte, error)
+	Context  *Context
+	Data     interface{}
+}
+
+type TextRenderer interface {
+	RenderTemplateText(text string) (string, error)
+}
+
+func NewTextRenderer(readFile func(filename string) ([]byte, error), basePath string, data interface{}) *templateTextRenderer {
+	return &templateTextRenderer{
+		ReadText: readFile,
+		Context: &Context{
+			basePath: basePath,
+			readFile: readFile,
+		},
+		Data: data,
+	}
+}
+
+func (r *templateTextRenderer) RenderTemplateText(text string) (string, error) {
+	buf, err := r.Context.RenderTemplateToBuffer(text, r.Data)
+	if err != nil {
+		return "", err
+	}
+	return buf.String(), nil
+}

valuesfile/valuesfile.go

@@ -1,39 +0,0 @@
-package valuesfile
-
-import (
-	"fmt"
-	"github.com/roboll/helmfile/environment"
-	"github.com/roboll/helmfile/tmpl"
-	"strings"
-)
-
-type renderer struct {
-	readFile         func(string) ([]byte, error)
-	tmplFileRenderer tmpl.FileRenderer
-}
-
-func NewRenderer(readFile func(filename string) ([]byte, error), basePath string, env environment.Environment) *renderer {
-	return &renderer{
-		readFile:         readFile,
-		tmplFileRenderer: tmpl.NewFileRenderer(readFile, basePath, env, ""),
-	}
-}
-
-func (r *renderer) RenderToBytes(path string) ([]byte, error) {
-	var yamlBytes []byte
-	splits := strings.Split(path, ".")
-	if len(splits) > 0 && splits[len(splits)-1] == "gotmpl" {
-		yamlBuf, err := r.tmplFileRenderer.RenderTemplateFileToBuffer(path)
-		if err != nil {
-			return nil, fmt.Errorf("failed to render [%s], because of %v", path, err)
-		}
-		yamlBytes = yamlBuf.Bytes()
-	} else {
-		var err error
-		yamlBytes, err = r.readFile(path)
-		if err != nil {
-			return nil, fmt.Errorf("failed to load [%s]: %v", path, err)
-		}
-	}
-	return yamlBytes, nil
-}

vendor/github.com/imdario/mergo/README.md

@@ -27,7 +27,7 @@ It is ready for production use. [It is used in several projects by Docker, Googl
 
 ### Latest release
 
-[Release v0.3.4](https://github.com/imdario/mergo/releases/tag/v0.3.4).
+[Release v0.3.6](https://github.com/imdario/mergo/releases/tag/v0.3.6).
 
 ### Important note
 

vendor/github.com/imdario/mergo/merge.go

@@ -9,6 +9,7 @@
 package mergo
 
 import (
+	"fmt"
 	"reflect"
 )
 
@@ -103,7 +104,15 @@ func deepMerge(dst, src reflect.Value, visited map[uintptr]*visit, depth int, co
 				case reflect.Ptr:
 					fallthrough
 				case reflect.Map:
-					if err = deepMerge(dstElement, srcElement, visited, depth+1, config); err != nil {
+					srcMapElm := srcElement
+					dstMapElm := dstElement
+					if srcMapElm.CanInterface() {
+						srcMapElm = reflect.ValueOf(srcMapElm.Interface())
+						if dstMapElm.IsValid() {
+							dstMapElm = reflect.ValueOf(dstMapElm.Interface())
+						}
+					}
+					if err = deepMerge(dstMapElm, srcMapElm, visited, depth+1, config); err != nil {
 						return
 					}
 				case reflect.Slice:
@@ -116,7 +125,14 @@ func deepMerge(dst, src reflect.Value, visited map[uintptr]*visit, depth int, co
 						dstSlice = reflect.ValueOf(dstElement.Interface())
 					}
 
-					dstSlice = reflect.AppendSlice(dstSlice, srcSlice)
+					if !isEmptyValue(src) && (overwrite || isEmptyValue(dst)) && !config.AppendSlice {
+						dstSlice = srcSlice
+					} else if config.AppendSlice {
+						if srcSlice.Type() != dstSlice.Type() {
+							return fmt.Errorf("cannot append two slice with different type (%s, %s)", srcSlice.Type(), dstSlice.Type())
+						}
+						dstSlice = reflect.AppendSlice(dstSlice, srcSlice)
+					}
 					dst.SetMapIndex(key, dstSlice)
 				}
 			}
@@ -124,7 +140,7 @@ func deepMerge(dst, src reflect.Value, visited map[uintptr]*visit, depth int, co
 				continue
 			}
 
-			if srcElement.IsValid() && (overwrite || (!dstElement.IsValid() || isEmptyValue(dst))) {
+			if srcElement.IsValid() && (overwrite || (!dstElement.IsValid() || isEmptyValue(dstElement))) {
 				if dst.IsNil() {
 					dst.Set(reflect.MakeMap(dst.Type()))
 				}
@@ -137,7 +153,10 @@ func deepMerge(dst, src reflect.Value, visited map[uintptr]*visit, depth int, co
 		}
 		if !isEmptyValue(src) && (overwrite || isEmptyValue(dst)) && !config.AppendSlice {
 			dst.Set(src)
-		} else {
+		} else if config.AppendSlice {
+			if src.Type() != dst.Type() {
+				return fmt.Errorf("cannot append two slice with different type (%s, %s)", src.Type(), dst.Type())
+			}
 			dst.Set(reflect.AppendSlice(dst, src))
 		}
 	case reflect.Ptr:

vendor/github.com/imdario/mergo/mergo.go

@@ -45,7 +45,12 @@ func isEmptyValue(v reflect.Value) bool {
 		return v.Uint() == 0
 	case reflect.Float32, reflect.Float64:
 		return v.Float() == 0
-	case reflect.Interface, reflect.Ptr, reflect.Func:
+	case reflect.Interface, reflect.Ptr:
+		if v.IsNil() {
+			return true
+		}
+		return isEmptyValue(v.Elem())
+	case reflect.Func:
 		return v.IsNil()
 	case reflect.Invalid:
 		return true