syncer: Update the conditions through statefulset changes.

Updates to statefulset spec for fields other than 'replicas','template', and 'updateStrategy' are forbidden.
So we can judge the status of the cluster according to the change of the `template` and `replicas`(updateStrategy
did not provide users to modify).

mysqlcluster/syncer/statefulset.go

@@ -20,6 +20,7 @@ import (
 	"context"
 	"errors"
 	"fmt"
+	"strings"
 	"time"
 
 	"github.com/go-test/deep"
@@ -263,20 +264,17 @@ func (s *StatefulSetSyncer) createOrUpdate(ctx context.Context) (controllerutil.
 		}
 	}
 	// Deep copy the old statefulset from StatefulSetSyncer.
-	existing := s.sfs.DeepCopyObject()
+	existing := s.sfs.DeepCopy()
 	// Sync data from mysqlcluster.spec to statefulset.
 	if err = s.mutate(); err != nil {
 		return controllerutil.OperationResultNone, err
 	}
 	// Check if statefulset changed.
-	if equality.Semantic.DeepEqual(existing, s.sfs) {
-		return controllerutil.OperationResultNone, nil
-	}
-	log.Info("update statefulset", "name", s.Name, "diff", deep.Equal(existing, s.sfs))
-
-	// If changed, update statefulset.
-	if err := s.cli.Update(ctx, s.sfs); err != nil {
-		return controllerutil.OperationResultNone, err
+	if s.stsUpdated(*existing) {
+		// If changed, update statefulset.
+		if err := s.cli.Update(ctx, s.sfs); err != nil {
+			return controllerutil.OperationResultNone, err
+		}
 	}
 	// Update every pods of statefulset.
 	if err := s.updatePod(ctx); err != nil {
@@ -292,7 +290,9 @@ func (s *StatefulSetSyncer) createOrUpdate(ctx context.Context) (controllerutil.
 // updatePod update the pods, update follower nodes first.
 // This can reduce the number of master-slave switching during the update process.
 func (s *StatefulSetSyncer) updatePod(ctx context.Context) error {
-	if s.sfs.Status.UpdateRevision == s.sfs.Status.CurrentRevision {
+	// updatedRevision wiil not update with the currentRevision when using `onDelete`.
+	// https://github.com/kubernetes/kubernetes/pull/106059
+	if s.sfs.Status.UpdatedReplicas == s.sfs.Status.ReadyReplicas {
 		return nil
 	}
 
@@ -475,7 +475,6 @@ func (s *StatefulSetSyncer) applyNWait(ctx context.Context, pod *corev1.Pod) err
 	if pod.ObjectMeta.Labels["controller-revision-hash"] == s.sfs.Status.UpdateRevision {
 		log.Info("pod is already updated", "pod name", pod.Name)
 	} else {
-		s.Status.State = apiv1alpha1.ClusterUpdateState
 		log.Info("updating pod", "pod", pod.Name, "key", s.Unwrap())
 		if pod.DeletionTimestamp != nil {
 			log.Info("pod is being deleted", "pod", pod.Name, "key", s.Unwrap())
@@ -590,3 +589,27 @@ func (s *StatefulSetSyncer) backupIsRunning(ctx context.Context) (bool, error) {
 	}
 	return false, nil
 }
+
+func (s *StatefulSetSyncer) stsUpdated(exist appsv1.StatefulSet) bool {
+	stsUpdated := false
+	if diff := deepEqualIgnoreNilSlice(exist.Spec.Template, s.sfs.Spec.Template); len(diff) > 0 {
+		log.Info("update statefulset", "name", s.Name, "diff", diff)
+		s.Status.UpdateClusterConditions(apiv1alpha1.ClusterUpdating, s.Status.GenerateUpdateCondition())
+		stsUpdated = true
+	}
+	if *exist.Spec.Replicas != *s.sfs.Spec.Replicas && !stsUpdated {
+		s.Status.UpdateClusterConditions(apiv1alpha1.ClusterScaling, s.Status.GenerateScaleCondition(*exist.Spec.Replicas, *s.sfs.Spec.Replicas))
+		stsUpdated = true
+	}
+	return stsUpdated
+}
+
+func deepEqualIgnoreNilSlice(a interface{}, b interface{}) []string {
+	diff := deep.Equal(a, b)
+	for i, v := range diff {
+		if strings.Contains(v, "<nil slice> != []") {
+			diff = append(diff[:i], diff[i+1:]...)
+		}
+	}
+	return diff
+}