mirror of
https://github.com/ceph/ceph-csi.git
synced 2024-11-10 08:20:23 +00:00
236 lines
9.9 KiB
Go
236 lines
9.9 KiB
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"
|
|
"sort"
|
|
|
|
"github.com/golang/glog"
|
|
"k8s.io/api/core/v1"
|
|
extensions "k8s.io/api/extensions/v1beta1"
|
|
"k8s.io/apimachinery/pkg/types"
|
|
"k8s.io/client-go/util/integer"
|
|
"k8s.io/kubernetes/pkg/controller"
|
|
deploymentutil "k8s.io/kubernetes/pkg/controller/deployment/util"
|
|
)
|
|
|
|
// rolloutRolling implements the logic for rolling a new replica set.
|
|
func (dc *DeploymentController) rolloutRolling(d *extensions.Deployment, rsList []*extensions.ReplicaSet, podMap map[types.UID]*v1.PodList) error {
|
|
newRS, oldRSs, err := dc.getAllReplicaSetsAndSyncRevision(d, rsList, podMap, true)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
allRSs := append(oldRSs, newRS)
|
|
|
|
// Scale up, if we can.
|
|
scaledUp, err := dc.reconcileNewReplicaSet(allRSs, newRS, d)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
if scaledUp {
|
|
// Update DeploymentStatus
|
|
return dc.syncRolloutStatus(allRSs, newRS, d)
|
|
}
|
|
|
|
// Scale down, if we can.
|
|
scaledDown, err := dc.reconcileOldReplicaSets(allRSs, controller.FilterActiveReplicaSets(oldRSs), newRS, d)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
if scaledDown {
|
|
// Update DeploymentStatus
|
|
return dc.syncRolloutStatus(allRSs, newRS, d)
|
|
}
|
|
|
|
if deploymentutil.DeploymentComplete(d, &d.Status) {
|
|
if err := dc.cleanupDeployment(oldRSs, d); err != nil {
|
|
return err
|
|
}
|
|
}
|
|
|
|
// Sync deployment status
|
|
return dc.syncRolloutStatus(allRSs, newRS, d)
|
|
}
|
|
|
|
func (dc *DeploymentController) reconcileNewReplicaSet(allRSs []*extensions.ReplicaSet, newRS *extensions.ReplicaSet, deployment *extensions.Deployment) (bool, error) {
|
|
if *(newRS.Spec.Replicas) == *(deployment.Spec.Replicas) {
|
|
// Scaling not required.
|
|
return false, nil
|
|
}
|
|
if *(newRS.Spec.Replicas) > *(deployment.Spec.Replicas) {
|
|
// Scale down.
|
|
scaled, _, err := dc.scaleReplicaSetAndRecordEvent(newRS, *(deployment.Spec.Replicas), deployment)
|
|
return scaled, err
|
|
}
|
|
newReplicasCount, err := deploymentutil.NewRSNewReplicas(deployment, allRSs, newRS)
|
|
if err != nil {
|
|
return false, err
|
|
}
|
|
scaled, _, err := dc.scaleReplicaSetAndRecordEvent(newRS, newReplicasCount, deployment)
|
|
return scaled, err
|
|
}
|
|
|
|
func (dc *DeploymentController) reconcileOldReplicaSets(allRSs []*extensions.ReplicaSet, oldRSs []*extensions.ReplicaSet, newRS *extensions.ReplicaSet, deployment *extensions.Deployment) (bool, error) {
|
|
oldPodsCount := deploymentutil.GetReplicaCountForReplicaSets(oldRSs)
|
|
if oldPodsCount == 0 {
|
|
// Can't scale down further
|
|
return false, nil
|
|
}
|
|
|
|
allPodsCount := deploymentutil.GetReplicaCountForReplicaSets(allRSs)
|
|
glog.V(4).Infof("New replica set %s/%s has %d available pods.", newRS.Namespace, newRS.Name, newRS.Status.AvailableReplicas)
|
|
maxUnavailable := deploymentutil.MaxUnavailable(*deployment)
|
|
|
|
// Check if we can scale down. We can scale down in the following 2 cases:
|
|
// * Some old replica sets have unhealthy replicas, we could safely scale down those unhealthy replicas since that won't further
|
|
// increase unavailability.
|
|
// * New replica set has scaled up and it's replicas becomes ready, then we can scale down old replica sets in a further step.
|
|
//
|
|
// maxScaledDown := allPodsCount - minAvailable - newReplicaSetPodsUnavailable
|
|
// take into account not only maxUnavailable and any surge pods that have been created, but also unavailable pods from
|
|
// the newRS, so that the unavailable pods from the newRS would not make us scale down old replica sets in a further
|
|
// step(that will increase unavailability).
|
|
//
|
|
// Concrete example:
|
|
//
|
|
// * 10 replicas
|
|
// * 2 maxUnavailable (absolute number, not percent)
|
|
// * 3 maxSurge (absolute number, not percent)
|
|
//
|
|
// case 1:
|
|
// * Deployment is updated, newRS is created with 3 replicas, oldRS is scaled down to 8, and newRS is scaled up to 5.
|
|
// * The new replica set pods crashloop and never become available.
|
|
// * allPodsCount is 13. minAvailable is 8. newRSPodsUnavailable is 5.
|
|
// * A node fails and causes one of the oldRS pods to become unavailable. However, 13 - 8 - 5 = 0, so the oldRS won't be scaled down.
|
|
// * The user notices the crashloop and does kubectl rollout undo to rollback.
|
|
// * newRSPodsUnavailable is 1, since we rolled back to the good replica set, so maxScaledDown = 13 - 8 - 1 = 4. 4 of the crashlooping pods will be scaled down.
|
|
// * The total number of pods will then be 9 and the newRS can be scaled up to 10.
|
|
//
|
|
// case 2:
|
|
// Same example, but pushing a new pod template instead of rolling back (aka "roll over"):
|
|
// * The new replica set created must start with 0 replicas because allPodsCount is already at 13.
|
|
// * However, newRSPodsUnavailable would also be 0, so the 2 old replica sets could be scaled down by 5 (13 - 8 - 0), which would then
|
|
// allow the new replica set to be scaled up by 5.
|
|
minAvailable := *(deployment.Spec.Replicas) - maxUnavailable
|
|
newRSUnavailablePodCount := *(newRS.Spec.Replicas) - newRS.Status.AvailableReplicas
|
|
maxScaledDown := allPodsCount - minAvailable - newRSUnavailablePodCount
|
|
if maxScaledDown <= 0 {
|
|
return false, nil
|
|
}
|
|
|
|
// Clean up unhealthy replicas first, otherwise unhealthy replicas will block deployment
|
|
// and cause timeout. See https://github.com/kubernetes/kubernetes/issues/16737
|
|
oldRSs, cleanupCount, err := dc.cleanupUnhealthyReplicas(oldRSs, deployment, maxScaledDown)
|
|
if err != nil {
|
|
return false, nil
|
|
}
|
|
glog.V(4).Infof("Cleaned up unhealthy replicas from old RSes by %d", cleanupCount)
|
|
|
|
// Scale down old replica sets, need check maxUnavailable to ensure we can scale down
|
|
allRSs = append(oldRSs, newRS)
|
|
scaledDownCount, err := dc.scaleDownOldReplicaSetsForRollingUpdate(allRSs, oldRSs, deployment)
|
|
if err != nil {
|
|
return false, nil
|
|
}
|
|
glog.V(4).Infof("Scaled down old RSes of deployment %s by %d", deployment.Name, scaledDownCount)
|
|
|
|
totalScaledDown := cleanupCount + scaledDownCount
|
|
return totalScaledDown > 0, nil
|
|
}
|
|
|
|
// cleanupUnhealthyReplicas will scale down old replica sets with unhealthy replicas, so that all unhealthy replicas will be deleted.
|
|
func (dc *DeploymentController) cleanupUnhealthyReplicas(oldRSs []*extensions.ReplicaSet, deployment *extensions.Deployment, maxCleanupCount int32) ([]*extensions.ReplicaSet, int32, error) {
|
|
sort.Sort(controller.ReplicaSetsByCreationTimestamp(oldRSs))
|
|
// Safely scale down all old replica sets with unhealthy replicas. Replica set will sort the pods in the order
|
|
// such that not-ready < ready, unscheduled < scheduled, and pending < running. This ensures that unhealthy replicas will
|
|
// been deleted first and won't increase unavailability.
|
|
totalScaledDown := int32(0)
|
|
for i, targetRS := range oldRSs {
|
|
if totalScaledDown >= maxCleanupCount {
|
|
break
|
|
}
|
|
if *(targetRS.Spec.Replicas) == 0 {
|
|
// cannot scale down this replica set.
|
|
continue
|
|
}
|
|
glog.V(4).Infof("Found %d available pods in old RS %s/%s", targetRS.Status.AvailableReplicas, targetRS.Namespace, targetRS.Name)
|
|
if *(targetRS.Spec.Replicas) == targetRS.Status.AvailableReplicas {
|
|
// no unhealthy replicas found, no scaling required.
|
|
continue
|
|
}
|
|
|
|
scaledDownCount := int32(integer.IntMin(int(maxCleanupCount-totalScaledDown), int(*(targetRS.Spec.Replicas)-targetRS.Status.AvailableReplicas)))
|
|
newReplicasCount := *(targetRS.Spec.Replicas) - scaledDownCount
|
|
if newReplicasCount > *(targetRS.Spec.Replicas) {
|
|
return nil, 0, fmt.Errorf("when cleaning up unhealthy replicas, got invalid request to scale down %s/%s %d -> %d", targetRS.Namespace, targetRS.Name, *(targetRS.Spec.Replicas), newReplicasCount)
|
|
}
|
|
_, updatedOldRS, err := dc.scaleReplicaSetAndRecordEvent(targetRS, newReplicasCount, deployment)
|
|
if err != nil {
|
|
return nil, totalScaledDown, err
|
|
}
|
|
totalScaledDown += scaledDownCount
|
|
oldRSs[i] = updatedOldRS
|
|
}
|
|
return oldRSs, totalScaledDown, nil
|
|
}
|
|
|
|
// scaleDownOldReplicaSetsForRollingUpdate scales down old replica sets when deployment strategy is "RollingUpdate".
|
|
// Need check maxUnavailable to ensure availability
|
|
func (dc *DeploymentController) scaleDownOldReplicaSetsForRollingUpdate(allRSs []*extensions.ReplicaSet, oldRSs []*extensions.ReplicaSet, deployment *extensions.Deployment) (int32, error) {
|
|
maxUnavailable := deploymentutil.MaxUnavailable(*deployment)
|
|
|
|
// Check if we can scale down.
|
|
minAvailable := *(deployment.Spec.Replicas) - maxUnavailable
|
|
// Find the number of available pods.
|
|
availablePodCount := deploymentutil.GetAvailableReplicaCountForReplicaSets(allRSs)
|
|
if availablePodCount <= minAvailable {
|
|
// Cannot scale down.
|
|
return 0, nil
|
|
}
|
|
glog.V(4).Infof("Found %d available pods in deployment %s, scaling down old RSes", availablePodCount, deployment.Name)
|
|
|
|
sort.Sort(controller.ReplicaSetsByCreationTimestamp(oldRSs))
|
|
|
|
totalScaledDown := int32(0)
|
|
totalScaleDownCount := availablePodCount - minAvailable
|
|
for _, targetRS := range oldRSs {
|
|
if totalScaledDown >= totalScaleDownCount {
|
|
// No further scaling required.
|
|
break
|
|
}
|
|
if *(targetRS.Spec.Replicas) == 0 {
|
|
// cannot scale down this ReplicaSet.
|
|
continue
|
|
}
|
|
// Scale down.
|
|
scaleDownCount := int32(integer.IntMin(int(*(targetRS.Spec.Replicas)), int(totalScaleDownCount-totalScaledDown)))
|
|
newReplicasCount := *(targetRS.Spec.Replicas) - scaleDownCount
|
|
if newReplicasCount > *(targetRS.Spec.Replicas) {
|
|
return 0, fmt.Errorf("when scaling down old RS, got invalid request to scale down %s/%s %d -> %d", targetRS.Namespace, targetRS.Name, *(targetRS.Spec.Replicas), newReplicasCount)
|
|
}
|
|
_, _, err := dc.scaleReplicaSetAndRecordEvent(targetRS, newReplicasCount, deployment)
|
|
if err != nil {
|
|
return totalScaledDown, err
|
|
}
|
|
|
|
totalScaledDown += scaleDownCount
|
|
}
|
|
|
|
return totalScaledDown, nil
|
|
}
|