allow for charts from OCI registries to specify a chart path

This change allows for a HelmRepository to point to e.g. "ghcr.io" and
then a HelmRelease pointing to the chart "stefanprodan/charts/podinfo"
in its `.spec.chart.spec.chart` field.

Related discussion: https://github.com/fluxcd/flux2/discussions/2959

Signed-off-by: Max Jonas Werner <max@e13.dev>

config/samples/source_v1beta2_helmchart_helmrepository-oci.yaml

@@ -0,0 +1,11 @@
+apiVersion: source.toolkit.fluxcd.io/v1beta2
+kind: HelmChart
+metadata:
+  name: helmchart-sample-oci
+spec:
+  chart: stefanprodan/charts/podinfo
+  version: '>=6.0.0 <7.0.0'
+  sourceRef:
+    kind: HelmRepository
+    name: helmrepository-sample-oci
+  interval: 1m

config/samples/source_v1beta2_helmrepository-oci.yaml

@@ -0,0 +1,8 @@
+apiVersion: source.toolkit.fluxcd.io/v1beta2
+kind: HelmRepository
+metadata:
+  name: helmrepository-sample-oci
+spec:
+  interval: 1m
+  type: oci
+  url: oci://ghcr.io/

hack/ci/e2e.sh

@@ -75,7 +75,9 @@ kubectl -n source-system rollout status deploy/source-controller --timeout=1m
 kubectl -n source-system wait gitrepository/gitrepository-sample --for=condition=ready --timeout=1m
 kubectl -n source-system wait ocirepository/ocirepository-sample --for=condition=ready --timeout=1m
 kubectl -n source-system wait helmrepository/helmrepository-sample --for=condition=ready --timeout=1m
+kubectl -n source-system wait helmrepository/helmrepository-sample-oci --for=condition=ready --timeout=1m
 kubectl -n source-system wait helmchart/helmchart-sample --for=condition=ready --timeout=1m
+kubectl -n source-system wait helmchart/helmchart-sample-oci --for=condition=ready --timeout=1m
 kubectl -n source-system delete -f "${ROOT_DIR}/config/samples"
 
 echo "Run HelmChart values file tests"

internal/helm/chart/builder.go

@@ -81,9 +81,9 @@ func (r RemoteReference) Validate() error {
 	if r.Name == "" {
 		return fmt.Errorf("no name set for remote chart reference")
 	}
-	name := regexp.MustCompile("^([-a-z0-9]*)$")
+	name := regexp.MustCompile("^([-a-z0-9]+/?)+$")
 	if !name.MatchString(r.Name) {
-		return fmt.Errorf("invalid chart name '%s': a valid name must be lower case letters and numbers and MAY be separated with dashes (-)", r.Name)
+		return fmt.Errorf("invalid chart name '%s': a valid name must be lower case letters and numbers and MAY be separated with dashes (-) or slashes (/)", r.Name)
 	}
 	return nil
 }

internal/helm/chart/builder_remote_test.go

@@ -234,7 +234,8 @@ func TestRemoteBuilder_BuildFromOCIChatRepository(t *testing.T) {
 
 	registryClient := &mockRegistryClient{
 		tags: map[string][]string{
-			"localhost:5000/my_repo/grafana": {"6.17.4"},
+			"localhost:5000/my_repo/grafana":         {"6.17.4"},
+			"localhost:5000/my_repo/another/grafana": {"6.17.4"},
 		},
 	}
 
@@ -318,6 +319,15 @@ func TestRemoteBuilder_BuildFromOCIChatRepository(t *testing.T) {
 				"replicaCount": float64(1),
 			},
 		},
+		{
+			name:        "default values",
+			reference:   RemoteReference{Name: "another/grafana"},
+			repository:  mockRepo(),
+			wantVersion: "0.1.0",
+			wantValues: chartutil.Values{
+				"replicaCount": float64(1),
+			},
+		},
 		{
 			name:      "merge values",
 			reference: RemoteReference{Name: "grafana"},

internal/helm/chart/builder_test.go

@@ -85,21 +85,34 @@ func TestRemoteReference_Validate(t *testing.T) {
 			name: "ref with name",
 			ref:  RemoteReference{Name: "valid-chart-name"},
 		},
+		{
+			name: "ref with single-character name",
+			ref:  RemoteReference{Name: "a"},
+		},
 		{
 			name:    "ref with invalid name",
 			ref:     RemoteReference{Name: "iNvAlID-ChArT-NAmE!"},
 			wantErr: "invalid chart name 'iNvAlID-ChArT-NAmE!'",
 		},
 		{
-			name:    "ref with Artifactory specific invalid format",
-			ref:     RemoteReference{Name: "i-shall/not"},
-			wantErr: "invalid chart name 'i-shall/not'",
+			name: "ref with Artifactory specific valid format",
+			ref:  RemoteReference{Name: "i-shall/not"},
 		},
 		{
 			name:    "ref without name",
 			ref:     RemoteReference{},
 			wantErr: "no name set for remote chart reference",
 		},
+		{
+			name:    "ref with only a slash",
+			ref:     RemoteReference{Name: "/"},
+			wantErr: "invalid chart name '/'",
+		},
+		{
+			name:    "ref with double slash",
+			ref:     RemoteReference{Name: "not//a/valid/chart"},
+			wantErr: "invalid chart name 'not//a/valid/chart'",
+		},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {