Creating new workerStatefulSet instead of patching when updating LWS template (#229)

* switched to only creating workerSts if no workerSts exists

* added deleteWorkerStatefulSet function

* fixed names in test, added delete of workerstatefulset on update to accomodate change from patch to create on delete

* cleanup

* removed outdated comments

* renamed delete function

* deleteWorkerStatefulSet only necessary after second update

Author: liurupeng

pkg/controllers/pod_controller.go

@@ -32,7 +32,6 @@ import (
 	coreapplyv1 "k8s.io/client-go/applyconfigurations/core/v1"
 	metaapplyv1 "k8s.io/client-go/applyconfigurations/meta/v1"
 	"k8s.io/klog/v2"
-	"k8s.io/utils/ptr"
 	ctrl "sigs.k8s.io/controller-runtime"
 	"sigs.k8s.io/controller-runtime/pkg/client"
 	"sigs.k8s.io/controller-runtime/pkg/client/apiutil"
@@ -146,19 +145,18 @@ func (r *PodReconciler) Reconcile(ctx context.Context, req ctrl.Request) (ctrl.R
 	if err != nil {
 		return ctrl.Result{}, err
 	}
-	patch := &unstructured.Unstructured{
+	workerStatefulSet := &unstructured.Unstructured{
 		Object: obj,
 	}
-	// Use server side apply and add fieldmanagaer to the lws owned fields
-	// If there are conflicts in the fields owned by the lws controller, lws will obtain the ownership and force override
-	// these fields to the ones desired by the lws controller. These fields are specified in the StatefulSetApplyConfiguration
-	// TODO b/316776287 add E2E test for SSA
-	err = r.Patch(ctx, patch, client.Apply, &client.PatchOptions{
-		FieldManager: fieldManager,
-		Force:        ptr.To[bool](true),
-	})
-	if err != nil {
-		return ctrl.Result{}, err
+
+	var workerSts appsv1.StatefulSet
+	if err := r.Get(ctx, types.NamespacedName{Name: pod.Name, Namespace: leaderWorkerSet.Namespace}, &workerSts); err != nil {
+		if client.IgnoreNotFound(err) != nil {
+			return ctrl.Result{}, err
+		}
+		if err = r.Create(ctx, workerStatefulSet); err != nil {
+			return ctrl.Result{}, err
+		}
 	}
 	log.V(2).Info("Worker Reconcile completed.")
 	return ctrl.Result{}, nil

test/integration/controllers/leaderworkerset_test.go

@@ -584,7 +584,7 @@ var _ = ginkgo.Describe("LeaderWorkerSet controller", func() {
 				},
 			},
 		}),
-		ginkgo.Entry("leaderTemplate changed with maxUnavailable=2", &testCase{
+		ginkgo.Entry("workerTemplate changed with maxUnavailable=2", &testCase{
 			makeLeaderWorkerSet: func(nsName string) *testing.LeaderWorkerSetWrapper {
 				return testing.BuildLeaderWorkerSet(nsName).Replica(4).MaxUnavailable(2)
 			},
@@ -662,7 +662,7 @@ var _ = ginkgo.Describe("LeaderWorkerSet controller", func() {
 				},
 			},
 		}),
-		ginkgo.Entry("leaderTemplate changed with maxUnavailable greater than replicas", &testCase{
+		ginkgo.Entry("workerTemplate changed with maxUnavailable greater than replicas", &testCase{
 			makeLeaderWorkerSet: func(nsName string) *testing.LeaderWorkerSetWrapper {
 				return testing.BuildLeaderWorkerSet(nsName).Replica(4).MaxUnavailable(10)
 			},

test/testutils/util.go

@@ -267,6 +267,7 @@ func SetLeaderPodToReady(ctx context.Context, k8sClient client.Client, podName s
 			Status: corev1.ConditionTrue,
 		}
 		leaderPod.Status.Conditions = append(leaderPod.Status.Conditions, condition)
+		deleteWorkerStatefulSetIfExists(ctx, k8sClient, podName, lws)
 		return k8sClient.Status().Update(ctx, &leaderPod)
 	}, Timeout, Interval).Should(gomega.Succeed())
 }
@@ -538,3 +539,17 @@ func SetLeaderPodsToReady(ctx context.Context, k8sClient client.Client, lws *lea
 		return k8sClient.Status().Update(ctx, &sts)
 	}, Timeout, Interval).Should(gomega.Succeed())
 }
+
+func deleteWorkerStatefulSetIfExists(ctx context.Context, k8sClient client.Client, statefulsetName string, lws *leaderworkerset.LeaderWorkerSet) {
+	// in cases where size = 1, the workerstatefulset does not exist
+	gomega.Eventually(func() error {
+		var sts appsv1.StatefulSet
+		if err := k8sClient.Get(ctx, types.NamespacedName{Name: statefulsetName, Namespace: lws.Namespace}, &sts); err != nil {
+			if client.IgnoreNotFound(err) != nil {
+				return err
+			}
+			return nil
+		}
+		return k8sClient.Delete(ctx, &sts)
+	}, Timeout, Interval).Should(gomega.Succeed())
+}