fix: apply post-renderer to output-dir-template output (#2531)

* fix: apply post-renderer to output-dir-template output When --output-dir and --post-renderer are both passed to helm template, Helm writes pre-post-renderer content to files and sends post-renderer output to stdout. This workaround strips --output-dir from helm flags, captures the post-renderer-processed stdout, and writes it to the output directory. Fixes #2515 Signed-off-by: yxxhero <aiopsclub@163.com> * test: add integration test for issue-2515 (post-renderer with output-dir-template) Verifies that --post-renderer output is written to files when --output-dir-template is set, instead of pre-renderer content. Signed-off-by: yxxhero <aiopsclub@163.com> * fix: address review comments - correct HasPrefix args, fix output dir structure, fix test mock init Agent-Logs-Url: https://github.com/helmfile/helmfile/sessions/33d92423-fc47-4080-8307-5af9b16dd9c6 Co-authored-by: yxxhero <11087727+yxxhero@users.noreply.github.com> * fix: wrap file operation errors with context in post-renderer workaround Agent-Logs-Url: https://github.com/helmfile/helmfile/sessions/33d92423-fc47-4080-8307-5af9b16dd9c6 Co-authored-by: yxxhero <11087727+yxxhero@users.noreply.github.com> * fix: correct chart path and use absolute case dir path in integration test Agent-Logs-Url: https://github.com/helmfile/helmfile/sessions/43b7a794-1e7b-4577-8829-deb544a1a105 Co-authored-by: yxxhero <11087727+yxxhero@users.noreply.github.com> * fix: restrict --output-dir + --post-renderer workaround to Helm 3 only Agent-Logs-Url: https://github.com/helmfile/helmfile/sessions/229b14e2-b1ad-4f19-bd00-b8f7821383cd Co-authored-by: yxxhero <11087727+yxxhero@users.noreply.github.com> * fix: clean up stale templates dir on re-runs in Helm 3 post-renderer workaround Agent-Logs-Url: https://github.com/helmfile/helmfile/sessions/f6c66284-8eca-4db3-8711-c9b6d3a9c179 Co-authored-by: yxxhero <11087727+yxxhero@users.noreply.github.com> * fix: detect --post-renderer=<path> form and use targeted file cleanup Agent-Logs-Url: https://github.com/helmfile/helmfile/sessions/8c9e4af4-84ae-4cbd-bc0a-8fcd9adddaed Co-authored-by: yxxhero <11087727+yxxhero@users.noreply.github.com> * feat: add Helm 4 post-renderer plugin and enable Helm 4 issue-2515 integration test Agent-Logs-Url: https://github.com/helmfile/helmfile/sessions/3da2949c-a9d6-4e16-9b4a-a7e241080089 Co-authored-by: yxxhero <11087727+yxxhero@users.noreply.github.com> * fix: search recursively for YAML files in Helm 4 output-dir integration test Agent-Logs-Url: https://github.com/helmfile/helmfile/sessions/c5d33143-f611-40db-b73a-e5189d944ffd Co-authored-by: yxxhero <11087727+yxxhero@users.noreply.github.com> * fix: limit find depth and truncate log in Helm 4 integration test fallback message Agent-Logs-Url: https://github.com/helmfile/helmfile/sessions/c5d33143-f611-40db-b73a-e5189d944ffd Co-authored-by: yxxhero <11087727+yxxhero@users.noreply.github.com> --------- Signed-off-by: yxxhero <aiopsclub@163.com> Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
2026-10-17 21:15:53 +02:00 · 2026-04-28 09:01:48 +08:00
parent b50c9d6256
commit 9fa0529304
8 changed files with 224 additions and 8 deletions
@@ -646,17 +646,77 @@ func (helm *execer) TemplateRelease(name string, chart string, flags ...string)
 	helm.logger.Infof("Templating release=%v, chart=%v", name, redactedURL(chart))
 	args := []string{"template", name, chart}

-	out, err := helm.exec(append(args, flags...), map[string]string{}, nil)
-
 	var outputToFile bool
+	var hasPostRenderer bool

 	for _, f := range flags {
-		if strings.HasPrefix("--output-dir", f) {
+		if f == "--output-dir" || strings.HasPrefix(f, "--output-dir=") {
 			outputToFile = true
-			break
+		}
+		if f == "--post-renderer" || strings.HasPrefix(f, "--post-renderer=") {
+			hasPostRenderer = true
 		}
 	}

+	if outputToFile && hasPostRenderer && helm.IsHelm3() {
+		// Helm 3 does not apply --post-renderer to files written by --output-dir.
+		// It writes pre-post-renderer content to files and sends post-renderer output to stdout.
+		// Helm 4 handles this correctly, so the workaround is only needed for Helm 3.
+		// Workaround: run without --output-dir, capture stdout (with post-renderer applied),
+		// and write the output to the output directory ourselves.
+		var outputDir string
+		filteredFlags := make([]string, 0, len(flags))
+		for i := 0; i < len(flags); i++ {
+			if flags[i] == "--output-dir" && i+1 < len(flags) {
+				outputDir = flags[i+1]
+				i++
+				continue
+			}
+			if strings.HasPrefix(flags[i], "--output-dir=") {
+				outputDir = strings.TrimPrefix(flags[i], "--output-dir=")
+				continue
+			}
+			filteredFlags = append(filteredFlags, flags[i])
+		}
+
+		if outputDir == "" {
+			return fmt.Errorf("output dir not found for template command")
+		}
+
+		out, err := helm.exec(append(args, filteredFlags...), map[string]string{}, nil)
+		if err != nil {
+			return err
+		}
+
+		templatesDir := filepath.Join(outputDir, "templates")
+		legacyOutputPath := filepath.Join(outputDir, name+".yaml")
+		outputPath := filepath.Join(templatesDir, name+".yaml")
+
+		if removeErr := os.Remove(legacyOutputPath); removeErr != nil && !os.IsNotExist(removeErr) {
+			return fmt.Errorf("failed to remove legacy output file %s: %w", legacyOutputPath, removeErr)
+		}
+
+		// Remove only the specific file written by the previous run to avoid clobbering
+		// unrelated files in a shared output directory.
+		if removeErr := os.Remove(outputPath); removeErr != nil && !os.IsNotExist(removeErr) {
+			return fmt.Errorf("failed to remove stale output file %s: %w", outputPath, removeErr)
+		}
+
+		if len(out) > 0 {
+			if mkdirErr := os.MkdirAll(templatesDir, 0755); mkdirErr != nil {
+				return fmt.Errorf("failed to create templates directory %s: %w", templatesDir, mkdirErr)
+			}
+
+			if writeErr := os.WriteFile(outputPath, append(out, '\n'), 0644); writeErr != nil {
+				return fmt.Errorf("failed to write output file %s: %w", outputPath, writeErr)
+			}
+			helm.logger.Debugf("Wrote post-renderer output to %s", outputPath)
+		}
+		return nil
+	}
+
+	out, err := helm.exec(append(args, flags...), map[string]string{}, nil)
+
 	if outputToFile {
 		// With --output-dir is passed to helm-template,
 		// we can safely direct all the logs from it to our logger.
@@ -21,8 +21,9 @@ import (
 // Mocking the command-line runner

 type mockRunner struct {
-	output []byte
-	err    error
+	output        []byte
+	versionOutput []byte // if set, returned for "helm version --short" probe; overrides default Helm 4 fallback
+	err           error
 }

 func (mock *mockRunner) ExecuteStdIn(cmd string, args []string, env map[string]string, stdin io.Reader) ([]byte, error) {
@@ -30,8 +31,13 @@ func (mock *mockRunner) ExecuteStdIn(cmd string, args []string, env map[string]s
 }

 func (mock *mockRunner) Execute(cmd string, args []string, env map[string]string, enableLiveOutput bool) ([]byte, error) {
-	if len(mock.output) == 0 && strings.Join(args, " ") == "version --short" {
-		return []byte("v4.0.1+g12500dd"), nil
+	if strings.Join(args, " ") == "version --short" {
+		if mock.versionOutput != nil {
+			return mock.versionOutput, nil
+		}
+		if len(mock.output) == 0 {
+			return []byte("v4.0.1+g12500dd"), nil
+		}
 	}
 	return mock.output, mock.err
 }
@@ -1255,6 +1261,64 @@ exec: helm --kubeconfig config --kube-context dev template release https://examp
 	}
 }

+func Test_Template_PostRendererWithOutputDir(t *testing.T) {
+	tests := []struct {
+		name             string
+		postRendererFlag string
+	}{
+		{"separate flags", "--post-renderer"},
+		{"combined flag", "--post-renderer=/bin/echo"},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			tmpDir := t.TempDir()
+			var buffer bytes.Buffer
+			logger := NewLogger(&buffer, "debug")
+
+			// Use Helm 3 version for the version probe so the Helm 3 workaround is applied.
+			// The workaround is not needed for Helm 4, which natively applies --post-renderer to --output-dir output.
+			runner := &mockRunner{versionOutput: []byte("v3.20.0")}
+			helm, err := New("helm", HelmExecOptions{}, logger, "config", "dev", runner)
+			if err != nil {
+				t.Fatalf("unexpected error: %v", err)
+			}
+
+			runner.output = []byte("apiVersion: v1\nkind: Namespace\n")
+
+			var flags []string
+			if tt.postRendererFlag == "--post-renderer" {
+				flags = []string{"--post-renderer", "/bin/echo", "--output-dir", tmpDir, "--values", "file.yml"}
+			} else {
+				flags = []string{tt.postRendererFlag, "--output-dir", tmpDir, "--values", "file.yml"}
+			}
+
+			err = helm.TemplateRelease("myrelease", "path/to/chart", flags...)
+			if err != nil {
+				t.Fatalf("unexpected error: %v", err)
+			}
+
+			outputPath := filepath.Join(tmpDir, "templates", "myrelease.yaml")
+			data, err := os.ReadFile(outputPath)
+			if err != nil {
+				t.Fatalf("expected output file %s to exist: %v", outputPath, err)
+			}
+
+			expected := "apiVersion: v1\nkind: Namespace\n\n"
+			if string(data) != expected {
+				t.Errorf("output file content:\nactual=%q\nexpect=%q", string(data), expected)
+			}
+
+			outputLog := buffer.String()
+			if strings.Contains(outputLog, "--output-dir") {
+				t.Errorf("helm should NOT have been called with --output-dir, got: %s", outputLog)
+			}
+			if !strings.Contains(outputLog, "--post-renderer") {
+				t.Errorf("helm should have been called with --post-renderer, got: %s", outputLog)
+			}
+		})
+	}
+}
+
 func Test_IsHelm3(t *testing.T) {
 	helm3Runner := mockRunner{output: []byte("v3.0.0+ge29ce2a\n")}
 	helm, err := New("helm", HelmExecOptions{}, NewLogger(os.Stdout, "info"), "", "dev", &helm3Runner)