Add --output-dir-template flag to the fetch command (#456)

* Add --output-dir-template flag to the fetch command

Signed-off-by: elchenberg <elchenberg@users.noreply.github.com>

cmd/fetch.go

@@ -5,6 +5,7 @@ import (
 
 	"github.com/helmfile/helmfile/pkg/app"
 	"github.com/helmfile/helmfile/pkg/config"
+	"github.com/helmfile/helmfile/pkg/state"
 )
 
 // NewFetchCmd returns fetch subcmd
@@ -34,6 +35,7 @@ func NewFetchCmd(globalCfg *config.GlobalImpl) *cobra.Command {
 	f.IntVar(&fetchOptions.Concurrency, "concurrency", 0, "maximum number of concurrent helm processes to run, 0 is unlimited")
 	f.BoolVar(&fetchOptions.SkipDeps, "skip-deps", false, `skip running "helm repo update" and "helm dependency build"`)
 	f.StringVar(&fetchOptions.OutputDir, "output-dir", "", "directory to store charts (default: temporary directory which is deleted when the command terminates)")
+	f.StringVar(&fetchOptions.OutputDirTemplate, "output-dir-template", state.DefaultFetchOutputDirTemplate, "go text template for generating the output directory")
 
 	return cmd
 }

pkg/app/app.go

@@ -349,6 +349,7 @@ func (a *App) Fetch(c FetchConfigProvider) error {
 			SkipRepos:         c.SkipDeps(),
 			SkipDeps:          c.SkipDeps(),
 			OutputDir:         c.OutputDir(),
+			OutputDirTemplate: c.OutputDirTemplate(),
 			Concurrency:       c.Concurrency(),
 		}, func() {
 		})

pkg/app/config.go

@@ -179,6 +179,7 @@ type LintConfigProvider interface {
 type FetchConfigProvider interface {
 	SkipDeps() bool
 	OutputDir() string
+	OutputDirTemplate() string
 
 	concurrencyConfig
 }

pkg/config/fetch.go

@@ -8,6 +8,8 @@ type FetchOptions struct {
 	SkipDeps bool
 	// OutputDir is the output directory
 	OutputDir string
+	// OutputDirTemplate is the go template to generate the path of output directory
+	OutputDirTemplate string
 }
 
 // NewFetchOptions creates a new Apply
@@ -43,3 +45,8 @@ func (c *FetchImpl) SkipDeps() bool {
 func (c *FetchImpl) OutputDir() string {
 	return c.FetchOptions.OutputDir
 }
+
+// OutputDirTemplate returns the go template to generate the path of output directory
+func (c *FetchImpl) OutputDirTemplate() string {
+	return c.FetchOptions.OutputDirTemplate
+}

pkg/state/state.go

@@ -359,6 +359,16 @@ const MissingFileHandlerWarn = "Warn"
 // MissingFileHandlerDebug is the debug returned when a file is missing
 const MissingFileHandlerDebug = "Debug"
 
+var DefaultFetchOutputDirTemplate = path.Join(
+	"{{ .OutputDir }}{{ if .Release.TillerNamespace }}",
+	"{{ .Release.TillerNamespace }}{{ end }}{{ if .Release.Namespace }}",
+	"{{ .Release.Namespace }}{{ end }}{{ if .Release.KubeContext }}",
+	"{{ .Release.KubeContext }}{{ end }}",
+	"{{ .Release.Name }}",
+	"{{ .ChartName }}",
+	"{{ or .Release.Version \"latest\" }}",
+)
+
 func (st *HelmState) ApplyOverrides(spec *ReleaseSpec) {
 	if st.OverrideKubeContext != "" {
 		spec.KubeContext = st.OverrideKubeContext
@@ -983,6 +993,7 @@ type ChartPrepareOptions struct {
 	Wait                   bool
 	WaitForJobs            bool
 	OutputDir              string
+	OutputDirTemplate      string
 	IncludeTransitiveNeeds bool
 	Concurrency            int
 }
@@ -1211,31 +1222,12 @@ func (st *HelmState) PrepareCharts(helm helmexec.Interface, dir string, concurre
 					//    For helm 2, we `helm fetch` with the version flags and call `helm template`
 					//    WITHOUT the version flags.
 				} else {
-					pathElems := []string{
+					chartPath, err = generateChartPath(chartName, dir, release, opts.OutputDirTemplate)
-						dir,
+					if err != nil {
+						results <- &chartPrepareResult{err: err}
+						return
 					}
 
-					if release.TillerNamespace != "" {
-						pathElems = append(pathElems, release.TillerNamespace)
-					}
-
-					if release.Namespace != "" {
-						pathElems = append(pathElems, release.Namespace)
-					}
-
-					if release.KubeContext != "" {
-						pathElems = append(pathElems, release.KubeContext)
-					}
-
-					chartVersion := "latest"
-					if release.Version != "" {
-						chartVersion = release.Version
-					}
-
-					pathElems = append(pathElems, release.Name, chartName, chartVersion)
-
-					chartPath = path.Join(pathElems...)
-
 					// only fetch chart if it is not already fetched
 					if _, err := os.Stat(chartPath); os.IsNotExist(err) {
 						fetchFlags := st.chartVersionFlags(release)
@@ -1244,6 +1236,8 @@ func (st *HelmState) PrepareCharts(helm helmexec.Interface, dir string, concurre
 							results <- &chartPrepareResult{err: err}
 							return
 						}
+					} else {
+						st.logger.Infof("\"%s\" has not been downloaded because the output directory \"%s\" already exists", chartName, chartPath)
 					}
 
 					// Set chartPath to be the path containing Chart.yaml, if found
@@ -3181,6 +3175,36 @@ func (st *HelmState) GenerateOutputDir(outputDir string, release *ReleaseSpec, o
 	return buf.String(), nil
 }
 
+// generateChartPath generates the path of the output directory of the `helmfile fetch` command.
+// It uses a go template with data from the chart name, output directory and release spec.
+// If no template was provided (via the `--output-dir-template` flag) it uses the DefaultFetchOutputDirTemplate.
+func generateChartPath(chartName string, outputDir string, release *ReleaseSpec, outputDirTemplate string) (string, error) {
+	if outputDirTemplate == "" {
+		outputDirTemplate = DefaultFetchOutputDirTemplate
+	}
+
+	t, err := template.New("output-dir-template").Parse(outputDirTemplate)
+	if err != nil {
+		return "", fmt.Errorf("parsing output-dir-template template %q: %w", outputDirTemplate, err)
+	}
+
+	buf := &bytes.Buffer{}
+	data := struct {
+		ChartName string
+		OutputDir string
+		Release   ReleaseSpec
+	}{
+		ChartName: chartName,
+		OutputDir: outputDir,
+		Release:   *release,
+	}
+	if err := t.Execute(buf, data); err != nil {
+		return "", fmt.Errorf("executing output-dir-template template: %w", err)
+	}
+
+	return buf.String(), nil
+}
+
 func (st *HelmState) GenerateOutputFilePath(release *ReleaseSpec, outputFileTemplate string) (string, error) {
 	// get absolute path of state file to generate a hash
 	// use this hash to write helm output in a specific directory by state file and release name

pkg/state/state_test.go

@@ -2812,3 +2812,149 @@ func TestGetOCIQualifiedChartName(t *testing.T) {
 		})
 	}
 }
+
+func TestGenerateChartPath(t *testing.T) {
+	tests := []struct {
+		testName          string
+		chartName         string
+		release           *ReleaseSpec
+		outputDir         string
+		outputDirTemplate string
+		wantErr           bool
+		expected          string
+	}{
+		{
+			testName:  "PathGeneratedWithGivenOutputDirAndDefaultReleaseVersion",
+			chartName: "chart-name",
+			release:   &ReleaseSpec{Name: "release-name"},
+			outputDir: "/output-dir",
+			wantErr:   false,
+			expected:  "/output-dir/release-name/chart-name/latest",
+		},
+		{
+			testName:  "PathGeneratedWithGivenOutputDirAndGivenReleaseVersion",
+			chartName: "chart-name",
+			release:   &ReleaseSpec{Name: "release-name", Version: "0.0.0"},
+			outputDir: "/output-dir",
+			wantErr:   false,
+			expected:  "/output-dir/release-name/chart-name/0.0.0",
+		},
+		{
+			testName:  "PathGeneratedWithGivenOutputDirAndGivenReleaseTillerNamespace",
+			chartName: "chart-name",
+			release:   &ReleaseSpec{Name: "release-name", TillerNamespace: "tiller-namespace"},
+			outputDir: "/output-dir",
+			wantErr:   false,
+			expected:  "/output-dir/tiller-namespace/release-name/chart-name/latest",
+		},
+		{
+			testName:  "PathGeneratedWithGivenOutputDirAndGivenReleaseNamespace",
+			chartName: "chart-name",
+			release:   &ReleaseSpec{Name: "release-name", Namespace: "release-namespace"},
+			outputDir: "/output-dir",
+			wantErr:   false,
+			expected:  "/output-dir/release-namespace/release-name/chart-name/latest",
+		},
+		{
+			testName:  "PathGeneratedWithGivenOutputDirAndGivenReleaseTillerNamespaceAndGivenReleaseNamespace",
+			chartName: "chart-name",
+			release:   &ReleaseSpec{Name: "release-name", TillerNamespace: "tiller-namespace", Namespace: "release-namespace"},
+			outputDir: "/output-dir",
+			wantErr:   false,
+			expected:  "/output-dir/tiller-namespace/release-namespace/release-name/chart-name/latest",
+		},
+		{
+			testName:  "PathGeneratedWithGivenOutputDirAndGivenReleaseKubeContext",
+			chartName: "chart-name",
+			release:   &ReleaseSpec{Name: "release-name", KubeContext: "kube-context"},
+			outputDir: "/output-dir",
+			wantErr:   false,
+			expected:  "/output-dir/kube-context/release-name/chart-name/latest",
+		},
+		{
+			testName:  "PathGeneratedWithGivenOutputDirAndGivenReleaseNamespaceAndGivenReleaseKubeContext",
+			chartName: "chart-name",
+			release:   &ReleaseSpec{Name: "release-name", Namespace: "release-namespace", KubeContext: "kube-context"},
+			outputDir: "/output-dir",
+			wantErr:   false,
+			expected:  "/output-dir/release-namespace/kube-context/release-name/chart-name/latest",
+		},
+		{
+			testName:  "PathGeneratedWithGivenOutputDirAndGivenReleaseTillerNamespaceAndGivenReleaseKubeContext",
+			chartName: "chart-name",
+			release:   &ReleaseSpec{Name: "release-name", TillerNamespace: "tiller-namespace", KubeContext: "kube-context"},
+			outputDir: "/output-dir",
+			wantErr:   false,
+			expected:  "/output-dir/tiller-namespace/kube-context/release-name/chart-name/latest",
+		},
+		{
+			testName:  "PathGeneratedWithGivenOutputDirAndGivenReleaseTillerNamespaceAndGivenReleaseNamespaceAndGivenReleaseKubeContext",
+			chartName: "chart-name",
+			release:   &ReleaseSpec{Name: "release-name", TillerNamespace: "tiller-namespace", Namespace: "release-namespace", KubeContext: "kube-context"},
+			outputDir: "/output-dir",
+			wantErr:   false,
+			expected:  "/output-dir/tiller-namespace/release-namespace/kube-context/release-name/chart-name/latest",
+		},
+		{
+			testName:          "PathGeneratedWithGivenOutputDirAndGivenOutputDirTemplateWithFieldNameOutputDir",
+			chartName:         "chart-name",
+			release:           &ReleaseSpec{Name: "release-name"},
+			outputDir:         "/output-dir",
+			outputDirTemplate: "{{ .OutputDir }}",
+			wantErr:           false,
+			expected:          "/output-dir",
+		},
+		{
+			testName:          "PathGeneratedWithGivenOutputDirAndGivenOutputDirTemplateWithFieldNamesOutputDirAndReleaseName",
+			chartName:         "chart-name",
+			release:           &ReleaseSpec{Name: "release-name"},
+			outputDir:         "/output-dir",
+			outputDirTemplate: "{{ .OutputDir }}/{{ .Release.Name }}",
+			wantErr:           false,
+			expected:          "/output-dir/release-name",
+		},
+		{
+			testName:          "PathGeneratedWithGivenOutputDirTemplateWithFieldNamesOutputDir",
+			chartName:         "chart-name",
+			release:           &ReleaseSpec{Name: "release-name"},
+			outputDirTemplate: "{{ .OutputDir }}",
+			wantErr:           false,
+			expected:          "",
+		},
+		{
+			testName:          "PathGeneratedWithGivenOutputDirTemplateWithFieldNameReleaseName",
+			chartName:         "chart-name",
+			release:           &ReleaseSpec{Name: "release-name"},
+			outputDirTemplate: "{{ .Release.Name }}",
+			wantErr:           false,
+			expected:          "release-name",
+		},
+		{
+			testName:          "PathGeneratedWithGivenOutputDirTemplateWithStringAndFieldNameReleaseName",
+			chartName:         "chart-name",
+			release:           &ReleaseSpec{Name: "release-name"},
+			outputDirTemplate: "./charts/{{ .Release.Name }}",
+			wantErr:           false,
+			expected:          "./charts/release-name",
+		},
+		{
+			testName:          "ErrorReturnedWithGivenInvalidOutputDirTemplate",
+			chartName:         "chart-name",
+			release:           &ReleaseSpec{Name: "release-name"},
+			outputDirTemplate: "{{ .OutputDir }",
+			wantErr:           true,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.testName, func(t *testing.T) {
+			got, err := generateChartPath(tt.chartName, tt.outputDir, tt.release, tt.outputDirTemplate)
+
+			if tt.wantErr {
+				require.Errorf(t, err, "GenerateChartPath() error \"%v\", want error", err)
+			} else {
+				require.NoError(t, err, "GenerateChartPath() error \"%v\", want no error", err)
+			}
+			require.Equalf(t, tt.expected, got, "GenerateChartPath() got \"%v\", want \"%v\"", got, tt.expected)
+		})
+	}
+}