feat: execute templates against postRendererHooks

This commit is supposed to add template support to post renderer args.
Also, to make it possible to template arguments that are added to helm
defaults, during the load, I'm removing default post renderer args from
the state and putting them to each release, unless custom args are
defined for the release.

Signed-off-by: Nikolai Rodionov <allanger@badhouseplants.net>

pkg/app/desired_state_file_loader.go

@@ -249,6 +249,14 @@ func (ld *desiredStateLoader) load(env, overrodeEnv *environment.Environment, ba
 			finalState.RenderedValues = currentState.RenderedValues
 		}
 
+		if len(finalState.HelmDefaults.PostRendererArgs) > 0 {
+			for i := range finalState.Releases {
+				if len(finalState.Releases[i].PostRendererArgs) == 0 {
+					finalState.Releases[i].PostRendererArgs = finalState.HelmDefaults.PostRendererArgs
+				}
+			}
+			finalState.HelmDefaults.PostRendererArgs = nil
+		}
 		env = &finalState.Env
 
 		ld.logger.Debugf("merged environment: %v", env)

pkg/state/release.go

@@ -90,6 +90,18 @@ func (r ReleaseSpec) ExecuteTemplateExpressions(renderer *tmpl.FileRenderer) (*R
 		result.Labels[key] = s.String()
 	}
 
+	{
+		postRendererArgs := []string{}
+		for _, ts := range result.PostRendererArgs {
+			postRendererArg, err := renderer.RenderTemplateContentToString([]byte(ts))
+			if err != nil {
+				return nil, fmt.Errorf("failed executing template expressions in release \"%s\".postRendererArgs = \"%s\": %v", r.Name, ts, err)
+			}
+			postRendererArgs = append(postRendererArgs, postRendererArg)
+		}
+		result.PostRendererArgs = postRendererArgs
+	}
+
 	if len(result.ValuesTemplate) > 0 {
 		for i, t := range result.ValuesTemplate {
 			switch ts := t.(type) {

pkg/state/state_exec_tmpl_test.go

@@ -123,6 +123,29 @@ func TestHelmState_executeTemplates(t *testing.T) {
 				Values:    []any{map[string]any{"key": "app-val0"}},
 			},
 		},
+		{
+			name: "Has template expressions in post renderer args",
+			input: ReleaseSpec{
+				Chart: "test-chart",
+				PostRendererArgs: []string{
+					"--release",
+					"{{ .Release.Name }}",
+					"--chart",
+					"{{ .Release.Chart }}",
+				},
+				Name: "test-release",
+			},
+			want: ReleaseSpec{
+				Chart: "test-chart",
+				Name:  "test-release",
+				PostRendererArgs: []string{
+					"--release",
+					"test-chart-dev",
+					"--chart",
+					"test-chart",
+				},
+			},
+		},
 	}
 
 	for i := range tests {