velero/pkg/podvolume/backupper.go

428 lines
14 KiB
Go

/*
Copyright 2018 the Velero contributors.
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 podvolume
import (
"context"
"fmt"
"sync"
"github.com/pkg/errors"
"github.com/sirupsen/logrus"
corev1api "k8s.io/api/core/v1"
metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
"k8s.io/apimachinery/pkg/util/sets"
corev1client "k8s.io/client-go/kubernetes/typed/core/v1"
"k8s.io/client-go/tools/cache"
"github.com/vmware-tanzu/velero/internal/resourcepolicies"
velerov1api "github.com/vmware-tanzu/velero/pkg/apis/velero/v1"
veleroclient "github.com/vmware-tanzu/velero/pkg/client"
clientset "github.com/vmware-tanzu/velero/pkg/generated/clientset/versioned"
"github.com/vmware-tanzu/velero/pkg/label"
"github.com/vmware-tanzu/velero/pkg/nodeagent"
"github.com/vmware-tanzu/velero/pkg/repository"
"github.com/vmware-tanzu/velero/pkg/util/boolptr"
"github.com/vmware-tanzu/velero/pkg/util/kube"
)
// Backupper can execute pod volume backups of volumes in a pod.
type Backupper interface {
// BackupPodVolumes backs up all specified volumes in a pod.
BackupPodVolumes(backup *velerov1api.Backup, pod *corev1api.Pod, volumesToBackup []string, resPolicies *resourcepolicies.Policies, log logrus.FieldLogger) ([]*velerov1api.PodVolumeBackup, *PVCBackupSummary, []error)
}
type backupper struct {
ctx context.Context
repoLocker *repository.RepoLocker
repoEnsurer *repository.Ensurer
veleroClient clientset.Interface
pvcClient corev1client.PersistentVolumeClaimsGetter
pvClient corev1client.PersistentVolumesGetter
podClient corev1client.PodsGetter
uploaderType string
results map[string]chan *velerov1api.PodVolumeBackup
resultsLock sync.Mutex
}
type skippedPVC struct {
PVC *corev1api.PersistentVolumeClaim
Reason string
}
// PVCBackupSummary is a summary for which PVCs are skipped, which are backed up after each execution of the Backupper
// The scope should be within one pod, so the volume name is the key for the maps
type PVCBackupSummary struct {
Backedup map[string]*corev1api.PersistentVolumeClaim
Skipped map[string]*skippedPVC
pvcMap map[string]*corev1api.PersistentVolumeClaim
}
func NewPVCBackupSummary() *PVCBackupSummary {
return &PVCBackupSummary{
Backedup: make(map[string]*corev1api.PersistentVolumeClaim),
Skipped: make(map[string]*skippedPVC),
pvcMap: make(map[string]*corev1api.PersistentVolumeClaim),
}
}
func (pbs *PVCBackupSummary) addBackedup(volumeName string) {
if pvc, ok := pbs.pvcMap[volumeName]; ok {
pbs.Backedup[volumeName] = pvc
delete(pbs.Skipped, volumeName)
}
}
func (pbs *PVCBackupSummary) addSkipped(volumeName string, reason string) {
if pvc, ok := pbs.pvcMap[volumeName]; ok {
if _, ok2 := pbs.Backedup[volumeName]; !ok2 { // if it's not backed up, add it to skipped
pbs.Skipped[volumeName] = &skippedPVC{
PVC: pvc,
Reason: reason,
}
}
}
}
func newBackupper(
ctx context.Context,
repoLocker *repository.RepoLocker,
repoEnsurer *repository.Ensurer,
podVolumeBackupInformer cache.SharedIndexInformer,
veleroClient clientset.Interface,
pvcClient corev1client.PersistentVolumeClaimsGetter,
pvClient corev1client.PersistentVolumesGetter,
podClient corev1client.PodsGetter,
uploaderType string,
log logrus.FieldLogger,
) *backupper {
b := &backupper{
ctx: ctx,
repoLocker: repoLocker,
repoEnsurer: repoEnsurer,
veleroClient: veleroClient,
pvcClient: pvcClient,
pvClient: pvClient,
podClient: podClient,
uploaderType: uploaderType,
results: make(map[string]chan *velerov1api.PodVolumeBackup),
}
podVolumeBackupInformer.AddEventHandler(
cache.ResourceEventHandlerFuncs{
UpdateFunc: func(_, obj interface{}) {
pvb := obj.(*velerov1api.PodVolumeBackup)
if pvb.Status.Phase == velerov1api.PodVolumeBackupPhaseCompleted || pvb.Status.Phase == velerov1api.PodVolumeBackupPhaseFailed {
b.resultsLock.Lock()
defer b.resultsLock.Unlock()
resChan, ok := b.results[resultsKey(pvb.Spec.Pod.Namespace, pvb.Spec.Pod.Name)]
if !ok {
log.Errorf("No results channel found for pod %s/%s to send pod volume backup %s/%s on", pvb.Spec.Pod.Namespace, pvb.Spec.Pod.Name, pvb.Namespace, pvb.Name)
return
}
resChan <- pvb
}
},
},
)
return b
}
func resultsKey(ns, name string) string {
return fmt.Sprintf("%s/%s", ns, name)
}
func (b *backupper) getMatchAction(resPolicies *resourcepolicies.Policies, pvc *corev1api.PersistentVolumeClaim, volume *corev1api.Volume) (*resourcepolicies.Action, error) {
if pvc != nil {
pv, err := b.pvClient.PersistentVolumes().Get(context.TODO(), pvc.Spec.VolumeName, metav1.GetOptions{})
if err != nil {
return nil, errors.Wrapf(err, "error getting pv for pvc %s", pvc.Spec.VolumeName)
}
return resPolicies.GetMatchAction(pv)
}
if volume != nil {
return resPolicies.GetMatchAction(volume)
}
return nil, errors.Errorf("failed to check resource policies for empty volume")
}
func (b *backupper) BackupPodVolumes(backup *velerov1api.Backup, pod *corev1api.Pod, volumesToBackup []string, resPolicies *resourcepolicies.Policies, log logrus.FieldLogger) ([]*velerov1api.PodVolumeBackup, *PVCBackupSummary, []error) {
if len(volumesToBackup) == 0 {
return nil, nil, nil
}
log.Infof("pod %s/%s has volumes to backup: %v", pod.Namespace, pod.Name, volumesToBackup)
err := nodeagent.IsRunningInNode(b.ctx, backup.Namespace, pod.Spec.NodeName, b.podClient)
if err != nil {
return nil, nil, []error{err}
}
repositoryType := getRepositoryType(b.uploaderType)
if repositoryType == "" {
err := errors.Errorf("empty repository type, uploader %s", b.uploaderType)
return nil, nil, []error{err}
}
repo, err := b.repoEnsurer.EnsureRepo(b.ctx, backup.Namespace, pod.Namespace, backup.Spec.StorageLocation, repositoryType)
if err != nil {
return nil, nil, []error{err}
}
// get a single non-exclusive lock since we'll wait for all individual
// backups to be complete before releasing it.
b.repoLocker.Lock(repo.Name)
defer b.repoLocker.Unlock(repo.Name)
resultsChan := make(chan *velerov1api.PodVolumeBackup)
b.resultsLock.Lock()
b.results[resultsKey(pod.Namespace, pod.Name)] = resultsChan
b.resultsLock.Unlock()
var (
errs []error
podVolumeBackups []*velerov1api.PodVolumeBackup
podVolumes = make(map[string]corev1api.Volume)
mountedPodVolumes = sets.String{}
attachedPodDevices = sets.String{}
)
pvcSummary := NewPVCBackupSummary()
// put the pod's volumes and the PVC associated in maps for efficient lookup below
for _, podVolume := range pod.Spec.Volumes {
podVolumes[podVolume.Name] = podVolume
if podVolume.PersistentVolumeClaim != nil {
pvc, err := b.pvcClient.PersistentVolumeClaims(pod.Namespace).Get(context.TODO(), podVolume.PersistentVolumeClaim.ClaimName, metav1.GetOptions{})
if err != nil {
errs = append(errs, errors.Wrap(err, "error getting persistent volume claim for volume"))
continue
}
pvcSummary.pvcMap[podVolume.Name] = pvc
}
}
if err := kube.IsPodRunning(pod); err != nil {
for _, volumeName := range volumesToBackup {
err := errors.Wrapf(err, "backup for volume %s is skipped", volumeName)
log.WithError(err).Warn("Skip pod volume")
pvcSummary.addSkipped(volumeName, fmt.Sprintf("the pod the PVC is mounted to, %s/%s, is not running", pod.Namespace, pod.Name))
}
return nil, pvcSummary, nil
}
for _, container := range pod.Spec.Containers {
for _, volumeMount := range container.VolumeMounts {
mountedPodVolumes.Insert(volumeMount.Name)
}
for _, volumeDevice := range container.VolumeDevices {
attachedPodDevices.Insert(volumeDevice.Name)
}
}
repoIdentifier := ""
if repositoryType == velerov1api.BackupRepositoryTypeRestic {
repoIdentifier = repo.Spec.ResticIdentifier
}
var numVolumeSnapshots int
for _, volumeName := range volumesToBackup {
volume, ok := podVolumes[volumeName]
if !ok {
log.Warnf("No volume named %s found in pod %s/%s, skipping", volumeName, pod.Namespace, pod.Name)
continue
}
var pvc *corev1api.PersistentVolumeClaim
if volume.PersistentVolumeClaim != nil {
pvc, ok = pvcSummary.pvcMap[volumeName]
if !ok {
// there should have been error happened retrieving the PVC and it's recorded already
continue
}
}
// hostPath volumes are not supported because they're not mounted into /var/lib/kubelet/pods, so our
// daemonset pod has no way to access their data.
isHostPath, err := isHostPathVolume(&volume, pvc, b.pvClient.PersistentVolumes())
if err != nil {
errs = append(errs, errors.Wrap(err, "error checking if volume is a hostPath volume"))
continue
}
if isHostPath {
log.Warnf("Volume %s in pod %s/%s is a hostPath volume which is not supported for pod volume backup, skipping", volumeName, pod.Namespace, pod.Name)
continue
}
// check if volume is a block volume
if attachedPodDevices.Has(volumeName) {
msg := fmt.Sprintf("volume %s declared in pod %s/%s is a block volume. Block volumes are not supported for fs backup, skipping",
volumeName, pod.Namespace, pod.Name)
log.Warn(msg)
pvcSummary.addSkipped(volumeName, msg)
continue
}
// volumes that are not mounted by any container should not be backed up, because
// its directory is not created
if !mountedPodVolumes.Has(volumeName) {
msg := fmt.Sprintf("volume %s is declared in pod %s/%s but not mounted by any container, skipping", volumeName, pod.Namespace, pod.Name)
log.Warn(msg)
pvcSummary.addSkipped(volumeName, msg)
continue
}
if resPolicies != nil {
if action, err := b.getMatchAction(resPolicies, pvc, &volume); err != nil {
errs = append(errs, errors.Wrapf(err, "error getting pv for pvc %s", pvc.Spec.VolumeName))
continue
} else if action != nil && action.Type == resourcepolicies.Skip {
log.Infof("skip backup of volume %s for the matched resource policies", volumeName)
pvcSummary.addSkipped(volumeName, "matched action is 'skip' in chosen resource policies")
continue
}
}
volumeBackup := newPodVolumeBackup(backup, pod, volume, repoIdentifier, b.uploaderType, pvc)
// TODO: once backupper is refactored to use controller-runtime, just pass client instead of anonymous func
if err := veleroclient.CreateRetryGenerateNameWithFunc(volumeBackup, func() error {
_, err := b.veleroClient.VeleroV1().PodVolumeBackups(volumeBackup.Namespace).Create(context.TODO(), volumeBackup, metav1.CreateOptions{})
return err
}); err != nil {
errs = append(errs, err)
continue
}
pvcSummary.addBackedup(volumeName)
numVolumeSnapshots++
}
ForEachVolume:
for i, count := 0, numVolumeSnapshots; i < count; i++ {
select {
case <-b.ctx.Done():
errs = append(errs, errors.New("timed out waiting for all PodVolumeBackups to complete"))
break ForEachVolume
case res := <-resultsChan:
switch res.Status.Phase {
case velerov1api.PodVolumeBackupPhaseCompleted:
podVolumeBackups = append(podVolumeBackups, res)
case velerov1api.PodVolumeBackupPhaseFailed:
errs = append(errs, errors.Errorf("pod volume backup failed: %s", res.Status.Message))
podVolumeBackups = append(podVolumeBackups, res)
}
}
}
b.resultsLock.Lock()
delete(b.results, resultsKey(pod.Namespace, pod.Name))
b.resultsLock.Unlock()
return podVolumeBackups, pvcSummary, errs
}
type pvGetter interface {
Get(ctx context.Context, name string, opts metav1.GetOptions) (*corev1api.PersistentVolume, error)
}
// isHostPathVolume returns true if the volume is either a hostPath pod volume or a persistent
// volume claim on a hostPath persistent volume, or false otherwise.
func isHostPathVolume(volume *corev1api.Volume, pvc *corev1api.PersistentVolumeClaim, pvGetter pvGetter) (bool, error) {
if volume.HostPath != nil {
return true, nil
}
if pvc == nil || pvc.Spec.VolumeName == "" {
return false, nil
}
pv, err := pvGetter.Get(context.TODO(), pvc.Spec.VolumeName, metav1.GetOptions{})
if err != nil {
return false, errors.WithStack(err)
}
return pv.Spec.HostPath != nil, nil
}
func newPodVolumeBackup(backup *velerov1api.Backup, pod *corev1api.Pod, volume corev1api.Volume, repoIdentifier, uploaderType string, pvc *corev1api.PersistentVolumeClaim) *velerov1api.PodVolumeBackup {
pvb := &velerov1api.PodVolumeBackup{
ObjectMeta: metav1.ObjectMeta{
Namespace: backup.Namespace,
GenerateName: backup.Name + "-",
OwnerReferences: []metav1.OwnerReference{
{
APIVersion: velerov1api.SchemeGroupVersion.String(),
Kind: "Backup",
Name: backup.Name,
UID: backup.UID,
Controller: boolptr.True(),
},
},
Labels: map[string]string{
velerov1api.BackupNameLabel: label.GetValidName(backup.Name),
velerov1api.BackupUIDLabel: string(backup.UID),
},
},
Spec: velerov1api.PodVolumeBackupSpec{
Node: pod.Spec.NodeName,
Pod: corev1api.ObjectReference{
Kind: "Pod",
Namespace: pod.Namespace,
Name: pod.Name,
UID: pod.UID,
},
Volume: volume.Name,
Tags: map[string]string{
"backup": backup.Name,
"backup-uid": string(backup.UID),
"pod": pod.Name,
"pod-uid": string(pod.UID),
"ns": pod.Namespace,
"volume": volume.Name,
},
BackupStorageLocation: backup.Spec.StorageLocation,
RepoIdentifier: repoIdentifier,
UploaderType: uploaderType,
},
}
if pvc != nil {
// this annotation is used in pkg/restore to identify if a PVC
// has a pod volume backup.
pvb.Annotations = map[string]string{
PVCNameAnnotation: pvc.Name,
}
// this label is used by the pod volume backup controller to tell
// if a pod volume backup is for a PVC.
pvb.Labels[velerov1api.PVCUIDLabel] = string(pvc.UID)
// this tag is not used by velero, but useful for debugging.
pvb.Spec.Tags["pvc-uid"] = string(pvc.UID)
}
return pvb
}
func errorOnly(_ interface{}, err error) error {
return err
}