helmchart: add ExternalArtifact as a valid source kind

ExternalArtifact (source.toolkit.fluxcd.io/v1) was introduced in
v1.7.0 but was never wired into the HelmChart controller. This commit
adds the necessary plumbing so that a HelmChart can reference an
ExternalArtifact as its source, enabling advanced source-composition
patterns via the source-watcher controller.

Changes:
- Extend LocalHelmChartSourceReference.Kind enum to include ExternalArtifact
- Register a Watch for ExternalArtifact in SetupWithManager
- Add ExternalArtifactKind case to getSource()
- Add *sourcev1.ExternalArtifact case to reconcileSource()
- Add requestsForExternalArtifactChange() reconcile-trigger helper

ExternalArtifact exposes a tarball artifact identical in structure to
Bucket and GitRepository, so it reuses the existing
buildFromTarballArtifact path with no new builder code required.

Signed-off-by: Rajit Shah <rajit219@gmail.com>

Author: cloudprobe

api/v1/helmchart_types.go

@@ -105,8 +105,8 @@ type LocalHelmChartSourceReference struct {
 	APIVersion string `json:"apiVersion,omitempty"`
 
 	// Kind of the referent, valid values are ('HelmRepository', 'GitRepository',
-	// 'Bucket').
-	// +kubebuilder:validation:Enum=HelmRepository;GitRepository;Bucket
+	// 'Bucket', 'ExternalArtifact').
+	// +kubebuilder:validation:Enum=HelmRepository;GitRepository;Bucket;ExternalArtifact
 	// +required
 	Kind string `json:"kind"`
 

internal/controller/helmchart_controller.go

@@ -201,6 +201,11 @@ func (r *HelmChartReconciler) SetupWithManager(ctx context.Context, mgr ctrl.Man
 			handler.EnqueueRequestsFromMapFunc(r.requestsForBucketChange),
 			builder.WithPredicates(SourceRevisionChangePredicate{}),
 		).
+		Watches(
+			&sourcev1.ExternalArtifact{},
+			handler.EnqueueRequestsFromMapFunc(r.requestsForExternalArtifactChange),
+			builder.WithPredicates(SourceRevisionChangePredicate{}),
+		).
 		WithOptions(controller.Options{
 			RateLimiter: opts.RateLimiter,
 		}).
@@ -508,6 +513,8 @@ func (r *HelmChartReconciler) reconcileSource(ctx context.Context, sp *patch.Ser
 		return r.buildFromHelmRepository(ctx, obj, typedSource, build)
 	case *sourcev1.GitRepository, *sourcev1.Bucket:
 		return r.buildFromTarballArtifact(ctx, obj, *typedSource.GetArtifact(), build)
+	case *sourcev1.ExternalArtifact:
+		return r.buildFromTarballArtifact(ctx, obj, *typedSource.GetArtifact(), build)
 	default:
 		// Ending up here should generally not be possible
 		// as getSource already validates
@@ -931,9 +938,15 @@ func (r *HelmChartReconciler) getSource(ctx context.Context, obj *sourcev1.HelmC
 			return nil, err
 		}
 		s = &bucket
+	case sourcev1.ExternalArtifactKind:
+		var ea sourcev1.ExternalArtifact
+		if err := r.Client.Get(ctx, namespacedName, &ea); err != nil {
+			return nil, err
+		}
+		s = &ea
 	default:
 		return nil, fmt.Errorf("unsupported source kind '%s', must be one of: %v", obj.Spec.SourceRef.Kind, []string{
-			sourcev1.HelmRepositoryKind, sourcev1.GitRepositoryKind, sourcev1.BucketKind})
+			sourcev1.HelmRepositoryKind, sourcev1.GitRepositoryKind, sourcev1.BucketKind, sourcev1.ExternalArtifactKind})
 	}
 	return s, nil
 }
@@ -1202,6 +1215,36 @@ func (r *HelmChartReconciler) requestsForBucketChange(ctx context.Context, o cli
 	return reqs
 }
 
+func (r *HelmChartReconciler) requestsForExternalArtifactChange(ctx context.Context, o client.Object) []reconcile.Request {
+	ea, ok := o.(*sourcev1.ExternalArtifact)
+	if !ok {
+		ctrl.LoggerFrom(ctx).Error(fmt.Errorf("expected an ExternalArtifact, got %T", o),
+			"failed to get reconcile requests for ExternalArtifact change")
+		return nil
+	}
+
+	// If we do not have an artifact, we have no requests to make
+	if ea.GetArtifact() == nil {
+		return nil
+	}
+
+	var list sourcev1.HelmChartList
+	if err := r.List(ctx, &list, client.MatchingFields{
+		indexKeyHelmChartSource: fmt.Sprintf("%s/%s", sourcev1.ExternalArtifactKind, ea.Name),
+	}); err != nil {
+		ctrl.LoggerFrom(ctx).Error(err, "failed to list HelmCharts for ExternalArtifact change")
+		return nil
+	}
+
+	var reqs []reconcile.Request
+	for i, v := range list.Items {
+		if !ea.GetArtifact().HasRevision(v.Status.ObservedSourceArtifactRevision) {
+			reqs = append(reqs, reconcile.Request{NamespacedName: client.ObjectKeyFromObject(&list.Items[i])})
+		}
+	}
+	return reqs
+}
+
 // eventLogf records events, and logs at the same time.
 //
 // This log is different from the debug log in the EventRecorder, in the sense