Fix VolumeClaimTemplates index out of range problem (#2493)

when the desired statefulset has different numbers of volume claim template with current cluster,  will be panic because of index out of range

Author: seekingua

pkg/cluster/cluster.go

@@ -480,23 +480,24 @@ func (c *Cluster) compareStatefulSetWith(statefulSet *appsv1.StatefulSet) *compa
 	if len(c.Statefulset.Spec.VolumeClaimTemplates) != len(statefulSet.Spec.VolumeClaimTemplates) {
 		needsReplace = true
 		reasons = append(reasons, "new statefulset's volumeClaimTemplates contains different number of volumes to the old one")
-	}
-	for i := 0; i < len(c.Statefulset.Spec.VolumeClaimTemplates); i++ {
-		name := c.Statefulset.Spec.VolumeClaimTemplates[i].Name
-		// Some generated fields like creationTimestamp make it not possible to use DeepCompare on ObjectMeta
-		if name != statefulSet.Spec.VolumeClaimTemplates[i].Name {
-			needsReplace = true
-			reasons = append(reasons, fmt.Sprintf("new statefulset's name for volume %d does not match the current one", i))
-			continue
-		}
-		if !reflect.DeepEqual(c.Statefulset.Spec.VolumeClaimTemplates[i].Annotations, statefulSet.Spec.VolumeClaimTemplates[i].Annotations) {
-			needsReplace = true
-			reasons = append(reasons, fmt.Sprintf("new statefulset's annotations for volume %q does not match the current one", name))
-		}
-		if !reflect.DeepEqual(c.Statefulset.Spec.VolumeClaimTemplates[i].Spec, statefulSet.Spec.VolumeClaimTemplates[i].Spec) {
+	} else {
+		for i := 0; i < len(c.Statefulset.Spec.VolumeClaimTemplates); i++ {
 			name := c.Statefulset.Spec.VolumeClaimTemplates[i].Name
-			needsReplace = true
-			reasons = append(reasons, fmt.Sprintf("new statefulset's volumeClaimTemplates specification for volume %q does not match the current one", name))
+			// Some generated fields like creationTimestamp make it not possible to use DeepCompare on ObjectMeta
+			if name != statefulSet.Spec.VolumeClaimTemplates[i].Name {
+				needsReplace = true
+				reasons = append(reasons, fmt.Sprintf("new statefulset's name for volume %d does not match the current one", i))
+				continue
+			}
+			if !reflect.DeepEqual(c.Statefulset.Spec.VolumeClaimTemplates[i].Annotations, statefulSet.Spec.VolumeClaimTemplates[i].Annotations) {
+				needsReplace = true
+				reasons = append(reasons, fmt.Sprintf("new statefulset's annotations for volume %q does not match the current one", name))
+			}
+			if !reflect.DeepEqual(c.Statefulset.Spec.VolumeClaimTemplates[i].Spec, statefulSet.Spec.VolumeClaimTemplates[i].Spec) {
+				name := c.Statefulset.Spec.VolumeClaimTemplates[i].Name
+				needsReplace = true
+				reasons = append(reasons, fmt.Sprintf("new statefulset's volumeClaimTemplates specification for volume %q does not match the current one", name))
+			}
 		}
 	}