ReplicaSet has owner ref of the Deployment that created it

pkg/controller/controller_ref_manager.go

@@ -23,6 +23,7 @@ import (
 	"github.com/golang/glog"
 	"k8s.io/kubernetes/pkg/api/errors"
 	"k8s.io/kubernetes/pkg/api/v1"
+	extensions "k8s.io/kubernetes/pkg/apis/extensions/v1beta1"
 	metav1 "k8s.io/kubernetes/pkg/apis/meta/v1"
 	"k8s.io/kubernetes/pkg/labels"
 	"k8s.io/kubernetes/pkg/runtime/schema"
@@ -143,3 +144,103 @@ func (m *PodControllerRefManager) ReleasePod(pod *v1.Pod) error {
 	}
 	return err
 }
+
+// ReplicaSetControllerRefManager is used to manage controllerRef of ReplicaSets.
+// Three methods are defined on this object 1: Classify 2: AdoptReplicaSet and
+// 3: ReleaseReplicaSet which are used to classify the ReplicaSets into appropriate
+// categories and accordingly adopt or release them. See comments on these functions
+// for more details.
+type ReplicaSetControllerRefManager struct {
+	rsControl          RSControlInterface
+	controllerObject   v1.ObjectMeta
+	controllerSelector labels.Selector
+	controllerKind     schema.GroupVersionKind
+}
+
+// NewReplicaSetControllerRefManager returns a ReplicaSetControllerRefManager that exposes
+// methods to manage the controllerRef of ReplicaSets.
+func NewReplicaSetControllerRefManager(
+	rsControl RSControlInterface,
+	controllerObject v1.ObjectMeta,
+	controllerSelector labels.Selector,
+	controllerKind schema.GroupVersionKind,
+) *ReplicaSetControllerRefManager {
+	return &ReplicaSetControllerRefManager{rsControl, controllerObject, controllerSelector, controllerKind}
+}
+
+// Classify, classifies the ReplicaSets into three categories:
+// 1. matchesAndControlled are the ReplicaSets whose labels
+// match the selector of the Deployment, and have a controllerRef pointing to the
+// Deployment.
+// 2. matchesNeedsController are ReplicaSets ,whose labels match the Deployment,
+// but don't have a controllerRef. (ReplicaSets with matching labels but with a
+// controllerRef pointing to other object are ignored)
+// 3. controlledDoesNotMatch are the ReplicaSets that have a controllerRef pointing
+// to the Deployment, but their labels no longer match the selector.
+func (m *ReplicaSetControllerRefManager) Classify(replicaSets []*extensions.ReplicaSet) (
+	matchesAndControlled []*extensions.ReplicaSet,
+	matchesNeedsController []*extensions.ReplicaSet,
+	controlledDoesNotMatch []*extensions.ReplicaSet) {
+	for i := range replicaSets {
+		replicaSet := replicaSets[i]
+		controllerRef := GetControllerOf(replicaSet.ObjectMeta)
+		if controllerRef != nil {
+			if controllerRef.UID != m.controllerObject.UID {
+				// ignoring the ReplicaSet controlled by other Deployment
+				glog.V(4).Infof("Ignoring ReplicaSet %v/%v, it's owned by [%s/%s, name: %s, uid: %s]",
+					replicaSet.Namespace, replicaSet.Name, controllerRef.APIVersion, controllerRef.Kind, controllerRef.Name, controllerRef.UID)
+				continue
+			}
+			// already controlled by this Deployment
+			if m.controllerSelector.Matches(labels.Set(replicaSet.Labels)) {
+				matchesAndControlled = append(matchesAndControlled, replicaSet)
+			} else {
+				controlledDoesNotMatch = append(controlledDoesNotMatch, replicaSet)
+			}
+		} else {
+			if !m.controllerSelector.Matches(labels.Set(replicaSet.Labels)) {
+				continue
+			}
+			matchesNeedsController = append(matchesNeedsController, replicaSet)
+		}
+	}
+	return matchesAndControlled, matchesNeedsController, controlledDoesNotMatch
+}
+
+// AdoptReplicaSet sends a patch to take control of the ReplicaSet. It returns the error if
+// the patching fails.
+func (m *ReplicaSetControllerRefManager) AdoptReplicaSet(replicaSet *extensions.ReplicaSet) error {
+	// we should not adopt any ReplicaSets if the Deployment is about to be deleted
+	if m.controllerObject.DeletionTimestamp != nil {
+		return fmt.Errorf("cancel the adopt attempt for RS %s because the controller %v is being deleted",
+			strings.Join([]string{replicaSet.Namespace, replicaSet.Name, string(replicaSet.UID)}, "_"), m.controllerObject.Name)
+	}
+	addControllerPatch := fmt.Sprintf(
+		`{"metadata":{"ownerReferences":[{"apiVersion":"%s","kind":"%s","name":"%s","uid":"%s","controller":true}],"uid":"%s"}}`,
+		m.controllerKind.GroupVersion(), m.controllerKind.Kind,
+		m.controllerObject.Name, m.controllerObject.UID, replicaSet.UID)
+	return m.rsControl.PatchReplicaSet(replicaSet.Namespace, replicaSet.Name, []byte(addControllerPatch))
+}
+
+// ReleaseReplicaSet sends a patch to free the ReplicaSet from the control of the Deployment controller.
+// It returns the error if the patching fails. 404 and 422 errors are ignored.
+func (m *ReplicaSetControllerRefManager) ReleaseReplicaSet(replicaSet *extensions.ReplicaSet) error {
+	glog.V(2).Infof("patching ReplicaSet %s_%s to remove its controllerRef to %s/%s:%s",
+		replicaSet.Namespace, replicaSet.Name, m.controllerKind.GroupVersion(), m.controllerKind.Kind, m.controllerObject.Name)
+	deleteOwnerRefPatch := fmt.Sprintf(`{"metadata":{"ownerReferences":[{"$patch":"delete","uid":"%s"}],"uid":"%s"}}`, m.controllerObject.UID, replicaSet.UID)
+	err := m.rsControl.PatchReplicaSet(replicaSet.Namespace, replicaSet.Name, []byte(deleteOwnerRefPatch))
+	if err != nil {
+		if errors.IsNotFound(err) {
+			// If the ReplicaSet no longer exists, ignore it.
+			return nil
+		}
+		if errors.IsInvalid(err) {
+			// Invalid error will be returned in two cases: 1. the ReplicaSet
+			// has no owner reference, 2. the uid of the ReplicaSet doesn't
+			// match, which means the ReplicaSet is deleted and then recreated.
+			// In both cases, the error can be ignored.
+			return nil
+		}
+	}
+	return err
+}