feat: Add ConditionTemplate support in releaseSpec (#2669)

* feat: Add ConditionTemplate support in releaseSpec

Signed-off-by: Arthur Garreau <arthur.garreau98@gmail.com>

* feat: improve testing, clarify doc

Signed-off-by: Arthur Garreau <arthur.garreau98@gmail.com>

* feat: update CHANGELOG for ConditionTemplate support and fix test cases for ID generation

Signed-off-by: Arthur Garreau <arthur.garreau98@gmail.com>

* Update pkg/state/state_exec_tmpl.go

Co-authored-by: yxxhero <11087727+yxxhero@users.noreply.github.com>
Signed-off-by: Arthur Garreau <arthur.garreau98@gmail.com>

* Update pkg/state/state_exec_tmpl.go

Co-authored-by: yxxhero <11087727+yxxhero@users.noreply.github.com>
Signed-off-by: Arthur Garreau <arthur.garreau98@gmail.com>

* Update docs/configuration.md

Co-authored-by: yxxhero <11087727+yxxhero@users.noreply.github.com>
Signed-off-by: Arthur Garreau <arthur.garreau98@gmail.com>

* refactor: improve comments for condition checks and clean up whitespace

Signed-off-by: Arthur Garreau <arthur.garreau98@gmail.com>

---------

Signed-off-by: Arthur Garreau <arthur.garreau98@gmail.com>
Co-authored-by: yxxhero <11087727+yxxhero@users.noreply.github.com>

docs/configuration.md

@@ -173,7 +173,7 @@ releases:
       foo: bar
     chart: roboll/vault-secret-manager     # the chart being installed to create this release, referenced by `repository/chart` syntax
     version: ~1.24.1                       # the semver of the chart. range constraint is supported
-    condition: vault.enabled               # The values lookup key for filtering releases. Corresponds to the boolean value of `vault.enabled`, where `vault` is an arbitrary value
+    condition: vault.enabled               # Filters releases by the boolean value at `vault.enabled`. Can also be set directly to true or false.
     missingFileHandler: Warn # set to either "Error" or "Warn". "Error" instructs helmfile to fail when unable to find a values or secrets file. When "Warn", it prints the file and continues.
     missingFileHandlerConfig:
       # Ignores missing git branch error so that the Debug/Info/Warn handler can treat a missing branch as non-error.
@@ -445,6 +445,12 @@ The following `helmDefaults` fields are also available but not shown in the exam
 
 ### Additional release fields
 
+#### Condition
+
+`condition` controls whether a release is enabled. An empty condition enables the release. A direct `true` or `false` value is treated as a literal boolean and bypasses values lookup. Any other condition must be a values lookup path ending in `.enabled`, such as `vault.enabled`.
+
+`conditionTemplate` is evaluated before `condition` is checked. It must render to a boolean value; when both `condition` and `conditionTemplate` are set, the rendered `conditionTemplate` value replaces `condition`. Like other `*Template` fields, `conditionTemplate` is not evaluated by the `list` command.
+
 The following per-release fields are also available:
 
 | Field | Type | Default | Description |
@@ -457,6 +463,7 @@ The following per-release fields are also available:
 | `verifyTemplate` | string | | Templated verify flag (e.g., `{{ .Values.verify \| default "false" }}`) |
 | `waitTemplate` | string | | Templated wait flag |
 | `installedTemplate` | string | | Templated installed flag |
+| `conditionTemplate` | string | | Templated condition flag. Must render to a boolean. When set with `condition`, the rendered value replaces `condition` |
 | `adopt` | list | | List of resources to adopt (passes `--adopt` to Helm) |
 | `forceGoGetter` | bool | false | Force go-getter URL parsing for the chart field. Useful when go-getter URL parsing fails unexpectedly |
 | `forceNamespace` | string | | Force namespace on all K8s resources rendered by the chart, even when the template doesn't use `{{ .Namespace }}`. Use with caution |

docs/writing-helmfile.md

@@ -118,12 +118,15 @@ Release Templating supports the following parts of release definition:
 
 - basic fields: `name`, `namespace`, `chart`, `version`
 
-- boolean fields: `installed`, `wait`, `waitForJobs`, `verify` by the means of additional text
-  fields designed for templating only: `installedTemplate`, `waitTemplate`, `verifyTemplate`
+- boolean fields: `installed`, `wait`, `waitForJobs`, `verify`, `condition` by the means of additional text
+  fields designed for templating only: `installedTemplate`, `waitTemplate`, `verifyTemplate`, `conditionTemplate`.
+  `conditionTemplate` must render to a boolean. When set with `condition`, the rendered value replaces `condition`.
+  `condition` accepts direct `true`/`false` values or a values lookup path ending in `.enabled`, for example `condition: vault.enabled`.
 
         # ...
           installedTemplate: '{{`{{ eq .Release.Namespace "kube-system" }}`}}'
           waitTemplate: '{{`{{ eq .Release.Labels.tag "safe" | not }}`}}'
+          conditionTemplate: '{{`{{ eq .Release.Namespace "kube-system"  }}`}}'
         # ...
 
 - `set` block values: