fix: cluster workflow template store is not initialized in namespace mode. Fixes #14763 (cherry-pick release-3.7)

pkg/apiclient/argo-kube-client.go

@@ -168,6 +168,8 @@ func (a *argoKubeClient) startStores(ctx context.Context, restConfig *restclient
 		} else {
 			a.cwfTmplStore = clusterworkflowtmplserver.NewClusterWorkflowTemplateClientStore()
 		}
+	} else {
+		a.cwfTmplStore = clusterworkflowtmplserver.NewNullClusterWorkflowTemplate()
 	}
 
 	return nil

server/apiserver/argoserver.go

@@ -238,12 +238,14 @@ func (as *argoServer) Run(ctx context.Context, port int, browserOpenFunc func(st
 		log.Fatal(err)
 	}
 	kubeclientset := kubernetes.NewForConfigOrDie(as.restConfig)
-	var cwftmplInformer *clusterworkflowtemplate.Informer
+	var cwftmplInformer clusterworkflowtemplate.ClusterWorkflowTemplateInformer
 	if rbacutil.HasAccessToClusterWorkflowTemplates(ctx, kubeclientset, resourceCacheNamespace) {
 		cwftmplInformer, err = clusterworkflowtemplate.NewInformer(as.restConfig)
 		if err != nil {
 			log.Fatal(err)
 		}
+	} else {
+		cwftmplInformer = clusterworkflowtemplate.NewNullClusterWorkflowTemplate()
 	}
 	eventRecorderManager := events.NewEventRecorderManager(as.clients.Kubernetes)
 	artifactRepositories := artifactrepositories.New(as.clients.Kubernetes, as.managedNamespace, &config.ArtifactRepository)

server/clusterworkflowtemplate/informer.go

@@ -20,6 +20,11 @@ const (
 	workflowTemplateResyncPeriod = 20 * time.Minute
 )
 
+type ClusterWorkflowTemplateInformer interface {
+	Run(stopCh <-chan struct{})
+	Getter(ctx context.Context) templateresolution.ClusterWorkflowTemplateGetter
+}
+
 var _ types.ClusterWorkflowTemplateStore = &Informer{}
 
 type Informer struct {
@@ -54,9 +59,10 @@ func (cwti *Informer) Run(stopCh <-chan struct{}) {
 }
 
 // if namespace contains empty string Lister will use the namespace provided during initialization
-func (cwti *Informer) Getter(_ context.Context) templateresolution.ClusterWorkflowTemplateGetter {
-	if cwti.informer == nil {
-		log.Fatal("Template informer not started")
+func (cwti *Informer) Getter(ctx context.Context) templateresolution.ClusterWorkflowTemplateGetter {
+	if cwti == nil || cwti.informer == nil {
+		log.Error("Template informer not started")
+		return nil
 	}
-	return cwti.informer.Lister()
+	return templateresolution.WrapClusterWorkflowTemplateLister(cwti.informer.Lister())
 }

server/clusterworkflowtemplate/null_client_store.go

@@ -0,0 +1,21 @@
+package clusterworkflowtemplate
+
+import (
+	"context"
+
+	"github.com/argoproj/argo-workflows/v3/workflow/templateresolution"
+)
+
+// NullClusterWorkflowTemplateStore is a no-op implementation of ClusterWorkflowTemplateStore
+// implements both informer and store interfaces
+type NullClusterWorkflowTemplateStore struct{}
+
+func NewNullClusterWorkflowTemplate() *NullClusterWorkflowTemplateStore {
+	return &NullClusterWorkflowTemplateStore{}
+}
+
+func (NullClusterWorkflowTemplateStore) Getter(context.Context) templateresolution.ClusterWorkflowTemplateGetter {
+	return &templateresolution.NullClusterWorkflowTemplateGetter{}
+}
+
+func (NullClusterWorkflowTemplateStore) Run(stopCh <-chan struct{}) {}

workflow/templateresolution/context.go

@@ -11,6 +11,7 @@ import (
 	"github.com/argoproj/argo-workflows/v3/errors"
 	wfv1 "github.com/argoproj/argo-workflows/v3/pkg/apis/workflow/v1alpha1"
 	typed "github.com/argoproj/argo-workflows/v3/pkg/client/clientset/versioned/typed/workflow/v1alpha1"
+	listers "github.com/argoproj/argo-workflows/v3/pkg/client/listers/workflow/v1alpha1"
 	"github.com/argoproj/argo-workflows/v3/workflow/common"
 )
 
@@ -57,6 +58,18 @@ func (n *NullClusterWorkflowTemplateGetter) Get(name string) (*wfv1.ClusterWorkf
 		"forbidden: User cannot get resource 'clusterworkflowtemplates' in API group argoproj.io at the cluster scope", name)
 }
 
+type clusterWorkflowTemplateListerWrapper struct {
+	lister listers.ClusterWorkflowTemplateLister
+}
+
+func WrapClusterWorkflowTemplateLister(lister listers.ClusterWorkflowTemplateLister) ClusterWorkflowTemplateGetter {
+	return &clusterWorkflowTemplateListerWrapper{lister: lister}
+}
+
+func (w *clusterWorkflowTemplateListerWrapper) Get(name string) (*wfv1.ClusterWorkflowTemplate, error) {
+	return w.lister.Get(name)
+}
+
 // Get retrieves the WorkflowTemplate of a given name.
 func (wrapper *clusterWorkflowTemplateInterfaceWrapper) Get(name string) (*wfv1.ClusterWorkflowTemplate, error) {
 	ctx := context.TODO()