Merge pull request #28068 from kargakis/refactor-deployment-controller

pkg/controller/deployment/recreate.go

+/*
+Copyright 2016 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package deployment
+
+import (
+	"k8s.io/kubernetes/pkg/apis/extensions"
+	"k8s.io/kubernetes/pkg/controller"
+)
+
+// rolloutRecreate implements the logic for recreating a replica set.
+func (dc *DeploymentController) rolloutRecreate(deployment *extensions.Deployment) error {
+	// Don't create a new RS if not already existed, so that we avoid scaling up before scaling down
+	newRS, oldRSs, err := dc.getAllReplicaSetsAndSyncRevision(deployment, false)
+	if err != nil {
+		return err
+	}
+	allRSs := append(oldRSs, newRS)
+
+	// scale down old replica sets
+	scaledDown, err := dc.scaleDownOldReplicaSetsForRecreate(controller.FilterActiveReplicaSets(oldRSs), deployment)
+	if err != nil {
+		return err
+	}
+	if scaledDown {
+		// Update DeploymentStatus
+		return dc.updateDeploymentStatus(allRSs, newRS, deployment)
+	}
+
+	// If we need to create a new RS, create it now
+	// TODO: Create a new RS without re-listing all RSs.
+	if newRS == nil {
+		newRS, oldRSs, err = dc.getAllReplicaSetsAndSyncRevision(deployment, true)
+		if err != nil {
+			return err
+		}
+		allRSs = append(oldRSs, newRS)
+	}
+
+	// scale up new replica set
+	scaledUp, err := dc.scaleUpNewReplicaSetForRecreate(newRS, deployment)
+	if err != nil {
+		return err
+	}
+	if scaledUp {
+		// Update DeploymentStatus
+		return dc.updateDeploymentStatus(allRSs, newRS, deployment)
+	}
+
+	dc.cleanupDeployment(oldRSs, deployment)
+
+	// Sync deployment status
+	return dc.syncDeploymentStatus(allRSs, newRS, deployment)
+}
+
+// scaleDownOldReplicaSetsForRecreate scales down old replica sets when deployment strategy is "Recreate"
+func (dc *DeploymentController) scaleDownOldReplicaSetsForRecreate(oldRSs []*extensions.ReplicaSet, deployment *extensions.Deployment) (bool, error) {
+	scaled := false
+	for _, rs := range oldRSs {
+		// Scaling not required.
+		if rs.Spec.Replicas == 0 {
+			continue
+		}
+		scaledRS, _, err := dc.scaleReplicaSetAndRecordEvent(rs, 0, deployment)
+		if err != nil {
+			return false, err
+		}
+		if scaledRS {
+			scaled = true
+		}
+	}
+	return scaled, nil
+}
+
+// scaleUpNewReplicaSetForRecreate scales up new replica set when deployment strategy is "Recreate"
+func (dc *DeploymentController) scaleUpNewReplicaSetForRecreate(newRS *extensions.ReplicaSet, deployment *extensions.Deployment) (bool, error) {
+	scaled, _, err := dc.scaleReplicaSetAndRecordEvent(newRS, deployment.Spec.Replicas, deployment)
+	return scaled, err
+}

pkg/controller/deployment/rollback.go

+/*
+Copyright 2016 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package deployment
+
+import (
+	"fmt"
+	"reflect"
+
+	"github.com/golang/glog"
+	"k8s.io/kubernetes/pkg/api"
+	"k8s.io/kubernetes/pkg/apis/extensions"
+	deploymentutil "k8s.io/kubernetes/pkg/util/deployment"
+)
+
+// Rolling back to a revision; no-op if the toRevision is deployment's current revision
+func (dc *DeploymentController) rollback(deployment *extensions.Deployment, toRevision *int64) (*extensions.Deployment, error) {
+	newRS, allOldRSs, err := dc.getAllReplicaSetsAndSyncRevision(deployment, true)
+	if err != nil {
+		return nil, err
+	}
+	allRSs := append(allOldRSs, newRS)
+	// If rollback revision is 0, rollback to the last revision
+	if *toRevision == 0 {
+		if *toRevision = lastRevision(allRSs); *toRevision == 0 {
+			// If we still can't find the last revision, gives up rollback
+			dc.emitRollbackWarningEvent(deployment, deploymentutil.RollbackRevisionNotFound, "Unable to find last revision.")
+			// Gives up rollback
+			return dc.updateDeploymentAndClearRollbackTo(deployment)
+		}
+	}
+	for _, rs := range allRSs {
+		v, err := deploymentutil.Revision(rs)
+		if err != nil {
+			glog.V(4).Infof("Unable to extract revision from deployment's replica set %q: %v", rs.Name, err)
+			continue
+		}
+		if v == *toRevision {
+			glog.V(4).Infof("Found replica set %q with desired revision %d", rs.Name, v)
+			// rollback by copying podTemplate.Spec from the replica set, and increment revision number by 1
+			// no-op if the the spec matches current deployment's podTemplate.Spec
+			deployment, performedRollback, err := dc.rollbackToTemplate(deployment, rs)
+			if performedRollback && err == nil {
+				dc.emitRollbackNormalEvent(deployment, fmt.Sprintf("Rolled back deployment %q to revision %d", deployment.Name, *toRevision))
+			}
+			return deployment, err
+		}
+	}
+	dc.emitRollbackWarningEvent(deployment, deploymentutil.RollbackRevisionNotFound, "Unable to find the revision to rollback to.")
+	// Gives up rollback
+	return dc.updateDeploymentAndClearRollbackTo(deployment)
+}
+
+func (dc *DeploymentController) rollbackToTemplate(deployment *extensions.Deployment, rs *extensions.ReplicaSet) (d *extensions.Deployment, performedRollback bool, err error) {
+	if !reflect.DeepEqual(deploymentutil.GetNewReplicaSetTemplate(deployment), rs.Spec.Template) {
+		glog.Infof("Rolling back deployment %s to template spec %+v", deployment.Name, rs.Spec.Template.Spec)
+		deploymentutil.SetFromReplicaSetTemplate(deployment, rs.Spec.Template)
+		// set RS (the old RS we'll rolling back to) annotations back to the deployment;
+		// otherwise, the deployment's current annotations (should be the same as current new RS) will be copied to the RS after the rollback.
+		//
+		// For example,
+		// A Deployment has old RS1 with annotation {change-cause:create}, and new RS2 {change-cause:edit}.
+		// Note that both annotations are copied from Deployment, and the Deployment should be annotated {change-cause:edit} as well.
+		// Now, rollback Deployment to RS1, we should update Deployment's pod-template and also copy annotation from RS1.
+		// Deployment is now annotated {change-cause:create}, and we have new RS1 {change-cause:create}, old RS2 {change-cause:edit}.
+		//
+		// If we don't copy the annotations back from RS to deployment on rollback, the Deployment will stay as {change-cause:edit},
+		// and new RS1 becomes {change-cause:edit} (copied from deployment after rollback), old RS2 {change-cause:edit}, which is not correct.
+		setDeploymentAnnotationsTo(deployment, rs)
+		performedRollback = true
+	} else {
+		glog.V(4).Infof("Rolling back to a revision that contains the same template as current deployment %s, skipping rollback...", deployment.Name)
+		dc.emitRollbackWarningEvent(deployment, deploymentutil.RollbackTemplateUnchanged, fmt.Sprintf("The rollback revision contains the same template as current deployment %q", deployment.Name))
+	}
+	d, err = dc.updateDeploymentAndClearRollbackTo(deployment)
+	return
+}
+
+func (dc *DeploymentController) emitRollbackWarningEvent(deployment *extensions.Deployment, reason, message string) {
+	dc.eventRecorder.Eventf(deployment, api.EventTypeWarning, reason, message)
+}
+
+func (dc *DeploymentController) emitRollbackNormalEvent(deployment *extensions.Deployment, message string) {
+	dc.eventRecorder.Eventf(deployment, api.EventTypeNormal, deploymentutil.RollbackDone, message)
+}
+
+// updateDeploymentAndClearRollbackTo sets .spec.rollbackTo to nil and update the input deployment
+func (dc *DeploymentController) updateDeploymentAndClearRollbackTo(deployment *extensions.Deployment) (*extensions.Deployment, error) {
+	glog.V(4).Infof("Cleans up rollbackTo of deployment %s", deployment.Name)
+	deployment.Spec.RollbackTo = nil
+	return dc.client.Extensions().Deployments(deployment.ObjectMeta.Namespace).Update(deployment)
+}

pkg/controller/deployment/util.go

@@ -23,12 +23,123 @@ import (
 
 	"github.com/golang/glog"
 
+	"k8s.io/kubernetes/pkg/api/annotations"
 	"k8s.io/kubernetes/pkg/apis/extensions"
 	"k8s.io/kubernetes/pkg/controller"
 	deploymentutil "k8s.io/kubernetes/pkg/util/deployment"
 	"k8s.io/kubernetes/pkg/util/integer"
 )
 
+func maxRevision(allRSs []*extensions.ReplicaSet) int64 {
+	max := int64(0)
+	for _, rs := range allRSs {
+		if v, err := deploymentutil.Revision(rs); err != nil {
+			// Skip the replica sets when it failed to parse their revision information
+			glog.V(4).Infof("Error: %v. Couldn't parse revision for replica set %#v, deployment controller will skip it when reconciling revisions.", err, rs)
+		} else if v > max {
+			max = v
+		}
+	}
+	return max
+}
+
+// lastRevision finds the second max revision number in all replica sets (the last revision)
+func lastRevision(allRSs []*extensions.ReplicaSet) int64 {
+	max, secMax := int64(0), int64(0)
+	for _, rs := range allRSs {
+		if v, err := deploymentutil.Revision(rs); err != nil {
+			// Skip the replica sets when it failed to parse their revision information
+			glog.V(4).Infof("Error: %v. Couldn't parse revision for replica set %#v, deployment controller will skip it when reconciling revisions.", err, rs)
+		} else if v >= max {
+			secMax = max
+			max = v
+		} else if v > secMax {
+			secMax = v
+		}
+	}
+	return secMax
+}
+
+// setNewReplicaSetAnnotations sets new replica set's annotations appropriately by updating its revision and
+// copying required deployment annotations to it; it returns true if replica set's annotation is changed.
+func setNewReplicaSetAnnotations(deployment *extensions.Deployment, newRS *extensions.ReplicaSet, newRevision string, exists bool) bool {
+	// First, copy deployment's annotations (except for apply and revision annotations)
+	annotationChanged := copyDeploymentAnnotationsToReplicaSet(deployment, newRS)
+	// Then, update replica set's revision annotation
+	if newRS.Annotations == nil {
+		newRS.Annotations = make(map[string]string)
+	}
+	// The newRS's revision should be the greatest among all RSes. Usually, its revision number is newRevision (the max revision number
+	// of all old RSes + 1). However, it's possible that some of the old RSes are deleted after the newRS revision being updated, and
+	// newRevision becomes smaller than newRS's revision. We should only update newRS revision when it's smaller than newRevision.
+	if newRS.Annotations[deploymentutil.RevisionAnnotation] < newRevision {
+		newRS.Annotations[deploymentutil.RevisionAnnotation] = newRevision
+		annotationChanged = true
+		glog.V(4).Infof("Updating replica set %q revision to %s", newRS.Name, newRevision)
+	}
+	if !exists && setReplicasAnnotations(newRS, deployment.Spec.Replicas, deployment.Spec.Replicas+maxSurge(*deployment)) {
+		annotationChanged = true
+	}
+	return annotationChanged
+}
+
+var annotationsToSkip = map[string]bool{
+	annotations.LastAppliedConfigAnnotation:  true,
+	deploymentutil.RevisionAnnotation:        true,
+	deploymentutil.DesiredReplicasAnnotation: true,
+	deploymentutil.MaxReplicasAnnotation:     true,
+}
+
+// skipCopyAnnotation returns true if we should skip copying the annotation with the given annotation key
+// TODO: How to decide which annotations should / should not be copied?
+//       See https://github.com/kubernetes/kubernetes/pull/20035#issuecomment-179558615
+func skipCopyAnnotation(key string) bool {
+	return annotationsToSkip[key]
+}
+
+// copyDeploymentAnnotationsToReplicaSet copies deployment's annotations to replica set's annotations,
+// and returns true if replica set's annotation is changed.
+// Note that apply and revision annotations are not copied.
+func copyDeploymentAnnotationsToReplicaSet(deployment *extensions.Deployment, rs *extensions.ReplicaSet) bool {
+	rsAnnotationsChanged := false
+	if rs.Annotations == nil {
+		rs.Annotations = make(map[string]string)
+	}
+	for k, v := range deployment.Annotations {
+		// newRS revision is updated automatically in getNewReplicaSet, and the deployment's revision number is then updated
+		// by copying its newRS revision number. We should not copy deployment's revision to its newRS, since the update of
+		// deployment revision number may fail (revision becomes stale) and the revision number in newRS is more reliable.
+		if skipCopyAnnotation(k) || rs.Annotations[k] == v {
+			continue
+		}
+		rs.Annotations[k] = v
+		rsAnnotationsChanged = true
+	}
+	return rsAnnotationsChanged
+}
+
+// setDeploymentAnnotationsTo sets deployment's annotations as given RS's annotations.
+// This action should be done if and only if the deployment is rolling back to this rs.
+// Note that apply and revision annotations are not changed.
+func setDeploymentAnnotationsTo(deployment *extensions.Deployment, rollbackToRS *extensions.ReplicaSet) {
+	deployment.Annotations = getSkippedAnnotations(deployment.Annotations)
+	for k, v := range rollbackToRS.Annotations {
+		if !skipCopyAnnotation(k) {
+			deployment.Annotations[k] = v
+		}
+	}
+}
+
+func getSkippedAnnotations(annotations map[string]string) map[string]string {
+	skippedAnnotations := make(map[string]string)
+	for k, v := range annotations {
+		if skipCopyAnnotation(k) {
+			skippedAnnotations[k] = v
+		}
+	}
+	return skippedAnnotations
+}
+
 // findActiveOrLatest returns the only active or the latest replica set in case there is at most one active
 // replica set. If there are more active replica sets, then we should proportionally scale them.
 func findActiveOrLatest(newRS *extensions.ReplicaSet, oldRSs []*extensions.ReplicaSet) *extensions.ReplicaSet {