feat(HelmChartSpec): optionally ignore missing valuesFiles

Signed-off-by: Robin Breathe <robin@isometry.net>

api/v1beta2/helmchart_types.go

@@ -79,6 +79,11 @@ type HelmChartSpec struct {
 	// +deprecated
 	ValuesFile string `json:"valuesFile,omitempty"`
 
+	// IgnoreMissingValuesFiles controls whether to silently ignore missing values
+	// files rather than failing.
+	// +optional
+	IgnoreMissingValuesFiles bool `json:"ignoreMissingValuesFiles,omitempty"`
+
 	// Suspend tells the controller to suspend the reconciliation of this
 	// source.
 	// +optional

config/crd/bases/source.toolkit.fluxcd.io_helmcharts.yaml

@@ -93,6 +93,11 @@ spec:
                 description: The name or path the Helm chart is available at in the
                   SourceRef.
                 type: string
+              ignoreMissingValuesFiles:
+                description: |-
+                  IgnoreMissingValuesFiles controls whether to silently ignore missing values
+                  files rather than failing.
+                type: boolean
               interval:
                 description: The interval at which to check the Source for updates.
                 type: string
@@ -363,6 +368,11 @@ spec:
                   Chart is the name or path the Helm chart is available at in the
                   SourceRef.
                 type: string
+              ignoreMissingValuesFiles:
+                description: |-
+                  IgnoreMissingValuesFiles controls whether to silently ignore missing values
+                  files rather than failing.
+                type: boolean
               interval:
                 description: |-
                   Interval at which the HelmChart SourceRef is checked for updates.

docs/api/v1beta2/source.md

@@ -660,6 +660,19 @@ is merged before the ValuesFiles items. Ignored when omitted.</p>
 </tr>
 <tr>
 <td>
+<code>ignoreMissingValuesFiles</code><br>
+<em>
+bool
+</em>
+</td>
+<td>
+<em>(Optional)</em>
+<p>Whether to silently ignore missing values files rather than failing.
+</p>
+</td>
+</tr>
+<tr>
+<td>
 <code>suspend</code><br>
 <em>
 bool
@@ -2329,6 +2342,19 @@ is merged before the ValuesFiles items. Ignored when omitted.</p>
 </tr>
 <tr>
 <td>
+<code>ignoreMissingValuesFiles</code><br>
+<em>
+bool
+</em>
+</td>
+<td>
+<em>(Optional)</em>
+<p>Whether to silently ignore missing values files rather than failing.
+</p>
+</td>
+</tr>
+<tr>
+<td>
 <code>suspend</code><br>
 <em>
 bool

internal/controller/helmchart_controller.go

@@ -665,8 +665,9 @@ func (r *HelmChartReconciler) buildFromHelmRepository(ctx context.Context, obj *
 	// Construct the chart builder with scoped configuration
 	cb := chart.NewRemoteBuilder(chartRepo)
 	opts := chart.BuildOptions{
-		ValuesFiles: obj.GetValuesFiles(),
-		Force:       obj.Generation != obj.Status.ObservedGeneration,
+		ValuesFiles:              obj.GetValuesFiles(),
+		IgnoreMissingValuesFiles: obj.Spec.IgnoreMissingValuesFiles,
+		Force:                    obj.Generation != obj.Status.ObservedGeneration,
 		// The remote builder will not attempt to download the chart if
 		// an artifact exists with the same name and version and `Force` is false.
 		// It will however try to verify the chart if `obj.Spec.Verify` is set, at every reconciliation.
@@ -760,8 +761,9 @@ func (r *HelmChartReconciler) buildFromTarballArtifact(ctx context.Context, obj
 
 	// Configure builder options, including any previously cached chart
 	opts := chart.BuildOptions{
-		ValuesFiles: obj.GetValuesFiles(),
-		Force:       obj.Generation != obj.Status.ObservedGeneration,
+		ValuesFiles:              obj.GetValuesFiles(),
+		IgnoreMissingValuesFiles: obj.Spec.IgnoreMissingValuesFiles,
+		Force:                    obj.Generation != obj.Status.ObservedGeneration,
 	}
 	if artifact := obj.Status.Artifact; artifact != nil {
 		opts.CachedChart = r.Storage.LocalPath(*artifact)

internal/helm/chart/builder.go

@@ -107,6 +107,8 @@ type BuildOptions struct {
 	// ValuesFiles can be set to a list of relative paths, used to compose
 	// and overwrite an alternative default "values.yaml" for the chart.
 	ValuesFiles []string
+	// IgnoreMissingValuesFiles controls whether to silently ignore missing values files rather than failing.
+	IgnoreMissingValuesFiles bool
 	// CachedChart can be set to the absolute path of a chart stored on
 	// the local filesystem, and is used for simple validation by metadata
 	// comparisons.

internal/helm/chart/builder_local.go

@@ -140,9 +140,12 @@ func (b *localChartBuilder) Build(ctx context.Context, ref Reference, p string,
 	}
 
 	// Merge chart values, if instructed
-	var mergedValues map[string]interface{}
+	var (
+		mergedValues map[string]interface{}
+		valuesFiles  []string
+	)
 	if len(opts.GetValuesFiles()) > 0 {
-		if mergedValues, err = mergeFileValues(localRef.WorkDir, opts.ValuesFiles); err != nil {
+		if mergedValues, valuesFiles, err = mergeFileValues(localRef.WorkDir, opts.ValuesFiles, opts.IgnoreMissingValuesFiles); err != nil {
 			return result, &BuildError{Reason: ErrValuesFilesMerge, Err: err}
 		}
 	}
@@ -163,7 +166,7 @@ func (b *localChartBuilder) Build(ctx context.Context, ref Reference, p string,
 		if err != nil {
 			return result, &BuildError{Reason: ErrValuesFilesMerge, Err: err}
 		}
-		result.ValuesFiles = opts.GetValuesFiles()
+		result.ValuesFiles = valuesFiles
 	}
 
 	// Ensure dependencies are fetched if building from a directory
@@ -187,31 +190,42 @@ func (b *localChartBuilder) Build(ctx context.Context, ref Reference, p string,
 }
 
 // mergeFileValues merges the given value file paths into a single "values.yaml" map.
-// The provided (relative) paths may not traverse outside baseDir. It returns the merge
-// result, or an error.
-func mergeFileValues(baseDir string, paths []string) (map[string]interface{}, error) {
+// The provided (relative) paths may not traverse outside baseDir. By default, a missing
+// file is considered an error. If ignoreMissing is set true, missing files are ignored.
+// It returns the merge result and the list of files that contributed to that result,
+// or an error.
+func mergeFileValues(baseDir string, paths []string, ignoreMissing bool) (map[string]interface{}, []string, error) {
 	mergedValues := make(map[string]interface{})
+	valuesFiles := make([]string, 0, len(paths))
 	for _, p := range paths {
 		secureP, err := securejoin.SecureJoin(baseDir, p)
 		if err != nil {
-			return nil, err
+			return nil, nil, err
 		}
-		if f, err := os.Stat(secureP); err != nil || !f.Mode().IsRegular() {
-			return nil, fmt.Errorf("no values file found at path '%s' (reference '%s')",
+		f, err := os.Stat(secureP)
+		switch {
+		case err != nil:
+			if ignoreMissing && os.IsNotExist(err) {
+				continue
+			}
+			fallthrough
+		case !f.Mode().IsRegular():
+			return nil, nil, fmt.Errorf("no values file found at path '%s' (reference '%s')",
 				strings.TrimPrefix(secureP, baseDir), p)
 		}
 		b, err := os.ReadFile(secureP)
 		if err != nil {
-			return nil, fmt.Errorf("could not read values from file '%s': %w", p, err)
+			return nil, nil, fmt.Errorf("could not read values from file '%s': %w", p, err)
 		}
 		values := make(map[string]interface{})
 		err = yaml.Unmarshal(b, &values)
 		if err != nil {
-			return nil, fmt.Errorf("unmarshaling values from '%s' failed: %w", p, err)
+			return nil, nil, fmt.Errorf("unmarshaling values from '%s' failed: %w", p, err)
 		}
 		mergedValues = transform.MergeMaps(mergedValues, values)
+		valuesFiles = append(valuesFiles, p)
 	}
-	return mergedValues, nil
+	return mergedValues, valuesFiles, nil
 }
 
 // copyFileToPath attempts to copy in to out. It returns an error if out already exists.

internal/helm/chart/builder_local_test.go

@@ -281,11 +281,13 @@ func TestLocalBuilder_Build_CachedChart(t *testing.T) {
 
 func Test_mergeFileValues(t *testing.T) {
 	tests := []struct {
-		name    string
-		files   []*helmchart.File
-		paths   []string
-		want    map[string]interface{}
-		wantErr string
+		name          string
+		files         []*helmchart.File
+		paths         []string
+		ignoreMissing bool
+		wantValues    map[string]interface{}
+		wantFiles     []string
+		wantErr       string
 	}{
 		{
 			name: "merges values from files",
@@ -295,10 +297,11 @@ func Test_mergeFileValues(t *testing.T) {
 				{Name: "c.yaml", Data: []byte("b: d")},
 			},
 			paths: []string{"a.yaml", "b.yaml", "c.yaml"},
-			want: map[string]interface{}{
+			wantValues: map[string]interface{}{
 				"a": "b",
 				"b": "d",
 			},
+			wantFiles: []string{"a.yaml", "b.yaml", "c.yaml"},
 		},
 		{
 			name:    "illegal traverse",
@@ -318,6 +321,25 @@ func Test_mergeFileValues(t *testing.T) {
 			paths:   []string{"a.yaml"},
 			wantErr: "no values file found at path '/a.yaml'",
 		},
+		{
+			name: "ignore missing files",
+			files: []*helmchart.File{
+				{Name: "a.yaml", Data: []byte("a: b")},
+			},
+			paths:         []string{"a.yaml", "b.yaml"},
+			ignoreMissing: true,
+			wantValues: map[string]interface{}{
+				"a": "b",
+			},
+			wantFiles: []string{"a.yaml"},
+		},
+		{
+			name:          "all files missing",
+			paths:         []string{"a.yaml"},
+			ignoreMissing: true,
+			wantValues:    map[string]interface{}{},
+			wantFiles:     []string{},
+		},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
@@ -329,16 +351,18 @@ func Test_mergeFileValues(t *testing.T) {
 				g.Expect(os.WriteFile(filepath.Join(baseDir, f.Name), f.Data, 0o640)).To(Succeed())
 			}
 
-			got, err := mergeFileValues(baseDir, tt.paths)
+			gotValues, gotFiles, err := mergeFileValues(baseDir, tt.paths, tt.ignoreMissing)
 			if tt.wantErr != "" {
 				g.Expect(err).To(HaveOccurred())
 				g.Expect(err.Error()).To(ContainSubstring(tt.wantErr))
-				g.Expect(got).To(BeNil())
+				g.Expect(gotValues).To(BeNil())
+				g.Expect(gotFiles).To(BeNil())
 				return
 			}
 
 			g.Expect(err).ToNot(HaveOccurred())
-			g.Expect(got).To(Equal(tt.want))
+			g.Expect(gotValues).To(Equal(tt.wantValues))
+			g.Expect(gotFiles).To(Equal(tt.wantFiles))
 		})
 	}
 }

internal/helm/chart/builder_remote.go

@@ -103,7 +103,7 @@ func (b *remoteChartBuilder) Build(ctx context.Context, ref Reference, p string,
 	}
 	chart.Metadata.Version = result.Version
 
-	mergedValues, err := mergeChartValues(chart, opts.ValuesFiles)
+	mergedValues, valuesFiles, err := mergeChartValues(chart, opts.ValuesFiles, opts.IgnoreMissingValuesFiles)
 	if err != nil {
 		err = fmt.Errorf("failed to merge chart values: %w", err)
 		return result, &BuildError{Reason: ErrValuesFilesMerge, Err: err}
@@ -113,7 +113,7 @@ func (b *remoteChartBuilder) Build(ctx context.Context, ref Reference, p string,
 		if err != nil {
 			return nil, &BuildError{Reason: ErrValuesFilesMerge, Err: err}
 		}
-		result.ValuesFiles = opts.GetValuesFiles()
+		result.ValuesFiles = valuesFiles
 	}
 
 	// Package the chart with the custom values
@@ -226,13 +226,18 @@ func setBuildMetaData(version, versionMetadata string) (*semver.Version, error)
 }
 
 // mergeChartValues merges the given chart.Chart Files paths into a single "values.yaml" map.
-// It returns the merge result, or an error.
-func mergeChartValues(chart *helmchart.Chart, paths []string) (map[string]interface{}, error) {
+// By default, a missing file is considered an error. If ignoreMissing is set true,
+// missing files are ignored.
+// It returns the merge result and the list of files that contributed to that result,
+// or an error.
+func mergeChartValues(chart *helmchart.Chart, paths []string, ignoreMissing bool) (map[string]interface{}, []string, error) {
 	mergedValues := make(map[string]interface{})
+	valuesFiles := make([]string, 0, len(paths))
 	for _, p := range paths {
 		cfn := filepath.Clean(p)
 		if cfn == chartutil.ValuesfileName {
 			mergedValues = transform.MergeMaps(mergedValues, chart.Values)
+			valuesFiles = append(valuesFiles, p)
 			continue
 		}
 		var b []byte
@@ -243,15 +248,19 @@ func mergeChartValues(chart *helmchart.Chart, paths []string) (map[string]interf
 			}
 		}
 		if b == nil {
-			return nil, fmt.Errorf("no values file found at path '%s'", p)
+			if ignoreMissing {
+				continue
+			}
+			return nil, nil, fmt.Errorf("no values file found at path '%s'", p)
 		}
 		values := make(map[string]interface{})
 		if err := yaml.Unmarshal(b, &values); err != nil {
-			return nil, fmt.Errorf("unmarshaling values from '%s' failed: %w", p, err)
+			return nil, nil, fmt.Errorf("unmarshaling values from '%s' failed: %w", p, err)
 		}
 		mergedValues = transform.MergeMaps(mergedValues, values)
+		valuesFiles = append(valuesFiles, p)
 	}
-	return mergedValues, nil
+	return mergedValues, valuesFiles, nil
 }
 
 // validatePackageAndWriteToPath atomically writes the packaged chart from reader

internal/helm/chart/builder_remote_test.go

@@ -443,11 +443,13 @@ entries:
 
 func Test_mergeChartValues(t *testing.T) {
 	tests := []struct {
-		name    string
-		chart   *helmchart.Chart
-		paths   []string
-		want    map[string]interface{}
-		wantErr string
+		name          string
+		chart         *helmchart.Chart
+		paths         []string
+		ignoreMissing bool
+		wantValues    map[string]interface{}
+		wantFiles     []string
+		wantErr       string
 	}{
 		{
 			name: "merges values",
@@ -459,10 +461,11 @@ func Test_mergeChartValues(t *testing.T) {
 				},
 			},
 			paths: []string{"a.yaml", "b.yaml", "c.yaml"},
-			want: map[string]interface{}{
+			wantValues: map[string]interface{}{
 				"a": "b",
 				"b": "d",
 			},
+			wantFiles: []string{"a.yaml", "b.yaml", "c.yaml"},
 		},
 		{
 			name: "uses chart values",
@@ -475,10 +478,11 @@ func Test_mergeChartValues(t *testing.T) {
 				},
 			},
 			paths: []string{chartutil.ValuesfileName, "c.yaml"},
-			want: map[string]interface{}{
+			wantValues: map[string]interface{}{
 				"a": "b",
 				"b": "d",
 			},
+			wantFiles: []string{chartutil.ValuesfileName, "c.yaml"},
 		},
 		{
 			name: "unmarshal error",
@@ -496,21 +500,59 @@ func Test_mergeChartValues(t *testing.T) {
 			paths:   []string{"a.yaml"},
 			wantErr: "no values file found at path 'a.yaml'",
 		},
+		{
+			name: "merges values ignoring file missing",
+			chart: &helmchart.Chart{
+				Files: []*helmchart.File{
+					{Name: "a.yaml", Data: []byte("a: b")},
+				},
+			},
+			paths:         []string{"a.yaml", "b.yaml"},
+			ignoreMissing: true,
+			wantValues: map[string]interface{}{
+				"a": "b",
+			},
+			wantFiles: []string{"a.yaml"},
+		},
+		{
+			name:          "merges values ignoring all missing",
+			chart:         &helmchart.Chart{},
+			paths:         []string{"a.yaml"},
+			ignoreMissing: true,
+			wantValues:    map[string]interface{}{},
+			wantFiles:     []string{},
+		},
+		{
+			name: "uses chart values ignoring missing file",
+			chart: &helmchart.Chart{
+				Values: map[string]interface{}{
+					"a": "b",
+				},
+			},
+			paths:         []string{chartutil.ValuesfileName, "c.yaml"},
+			ignoreMissing: true,
+			wantValues: map[string]interface{}{
+				"a": "b",
+			},
+			wantFiles: []string{chartutil.ValuesfileName},
+		},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
 			g := NewWithT(t)
 
-			got, err := mergeChartValues(tt.chart, tt.paths)
+			gotValues, gotFiles, err := mergeChartValues(tt.chart, tt.paths, tt.ignoreMissing)
 			if tt.wantErr != "" {
 				g.Expect(err).To(HaveOccurred())
 				g.Expect(err.Error()).To(ContainSubstring(tt.wantErr))
-				g.Expect(got).To(BeNil())
+				g.Expect(gotValues).To(BeNil())
+				g.Expect(gotFiles).To(BeNil())
 				return
 			}
 
 			g.Expect(err).ToNot(HaveOccurred())
-			g.Expect(got).To(Equal(tt.want))
+			g.Expect(gotValues).To(Equal(tt.wantValues))
+			g.Expect(gotFiles).To(Equal(tt.wantFiles))
 		})
 	}
 }