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

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Co-authored-by: yxxhero <11087727+yxxhero@users.noreply.github.com>

* fix: restrict --output-dir + --post-renderer workaround to Helm 3 only

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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

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Co-authored-by: yxxhero <11087727+yxxhero@users.noreply.github.com>

* fix: detect --post-renderer=<path> form and use targeted file cleanup

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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

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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>
This commit is contained in:
yxxhero
2026-04-28 09:01:48 +08:00
committed by GitHub
co-authored by copilot-swe-agent[bot]
parent b50c9d6256
commit 9fa0529304
8 changed files with 224 additions and 8 deletions
+68 -4
View File
@@ -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)