helmfile/docs/advanced-features.md

Advanced Features

• Import Configuration Parameters into Helmfile

Import Configuration Parameters into Helmfile

Helmfile integrates vals to import configuration parameters from following backends:

• AWS SSM Parameter Store
• AWS SecretsManager
• Vault
• SOPS

See Vals "Suported Backends" for the full list of available backends.

This feature was implemented in https://github.com/roboll/helmfile/pull/906. If you're curious how it's designed and how it works, please consult the pull request.

Deploy Kustomizations with Helmfile

You can deploy kustomize "kustomization"s with Helmfile.

Most of Kustomize operations that is usually done with kustomize edit can be done declaratively via Helm values.yaml files.

Under the hood, Helmfile transforms the kustomization into a local chart in a temporary directory so that it can be helm upgrade --installed.

The transformation is done by generating (1)a temporary kustomization from various options and (2)temporary chart from the temporary kustomization.

An example pseudo code for the transformation logic can be written as:

$ TMPCHART=/tmp/sometmpdir
$ mkdir -p ${TMPCHART}/templates
$ somehow_generate_chart_yaml ${TMPCHART}/Chart.yaml

$ TMPKUSTOMIZATION=/tmp/sometmpdir2
$ somehow_generate_temp_kustomization_yaml ${TMPKUSTOMIZATION}/kustomization.yaml
$ kustomize build ${TMPKUSTOMIZATION}/kustomization.yaml > ${TMPCHART}/templates/all.yaml 

Let's say you have a helmfile.yaml that looks like the below:

releases:
- name: myapp
  chart: mykustomization
  values:
  - values.yaml

Helmfile firstly generates a temporary kustomization.yaml that looks like:

bases:
- $(ABS_PATH_TO_HELMFILE_YAML}/mykustomization

Followed by the below steps:

• Running kustomize edit set image $IMAGE for every $IMAGE generated from your values.yaml
• Running kustomize edit set nameprefix $NAMEPREFIX with the nameprefix specified in your values.yaml
• Running kustomize edit set namesuffix $NAMESUFFIX with the namesuffix specified in your values.yaml
• Running kustomize edit set namespace $NS with the namespace specified in your values.yaml

A values.yaml file for kustomization would look like the below:

images:
# kustomize edit set image mysql=eu.gcr.io/my-project/mysql@canary
- name: mysql
  newName: eu.gcr.io/my-project/mysql
  newTag: canary
# kustomize edit set image myapp=my-registry/my-app@sha256:24a0c4b4a4c0eb97a1aabb8e29f18e917d05abfe1b7a7c07857230879ce7d3d3
- name: myapp
  digest: sha256:24a0c4b4a4c0eb97a1aabb8e29f18e917d05abfe1b7a7c07857230879ce7d3d3
  newName: my-registry/my-app

# kustomize edit set nameprefix foo-
namePrefix: foo-

# kustomize edit set namesuffix -bar
nameSuffix: -bar

# kustomize edit set namespace myapp
namespace: myapp

At this point, Helmfile can generate a complete kustomization from the base kustomization you specified in releases[].chart of your helmfile.yaml and values.yaml, which can be included in the temporary chart.

After all, Helmfile just installs the temporary chart like standard charts, which allows you to manage everything with Helmfile regardless of each app is declared using a Helm chart or a kustomization.