V2AS问路
Velero系列文章（四）：使用Velero进行生产迁移实战
阅读原文时间：2023年07月09日阅读：2

目的

通过 velero 工具, 实现以下整体目标:

  • 特定 namespace 在B A两个集群间做迁移;

具体目标为:

  1. 在B A集群上创建 velero (包括 restic )

  2. 备份 B集群 特定 namespace : caseycui2020:

  3. 迁移特定 namespace 到 A集群 : caseycui2020:

  4. 在您的本地目录中创建特定于Velero的凭证文件（credentials-velero):

    使用的是xsky的对象存储: (公司的netapp的对象存储不兼容)

    [default]
aws_access_key_id = xxxxxxxxxxxxxxxxxxxxxxxx
aws_secret_access_key = xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

  5. (openshift) 需要先创建 namespace : velero: oc new-project velero

  6. 默认情况下，用户维度的openshift namespace 不会在集群中的所有节点上调度Pod。

    要在所有节点上计划namespace，需要一个注释：

    oc annotate namespace velero openshift.io/node-selector=""

    这应该在安装velero之前完成。

  7. 启动服务器和存储服务。 在Velero目录中，运行：

    velero install \
    --provider aws \
    --plugins velero/velero-plugin-for-aws:v1.0.0 \
    --bucket velero \
    --secret-file ./credentials-velero \
    --use-restic \
    --use-volume-snapshots=true \
    --backup-location-config region="default",s3ForcePathStyle="true",s3Url="http://glacier.ewhisper.cn",insecureSkipTLSVerify="true",signatureVersion="4" \
    --snapshot-location-config region="default"

    创建的内容包括:

    CustomResourceDefinition/backups.velero.io: attempting to create resource
CustomResourceDefinition/backups.velero.io: created
CustomResourceDefinition/backupstoragelocations.velero.io: attempting to create resource
CustomResourceDefinition/backupstoragelocations.velero.io: created
CustomResourceDefinition/deletebackuprequests.velero.io: attempting to create resource
CustomResourceDefinition/deletebackuprequests.velero.io: created
CustomResourceDefinition/downloadrequests.velero.io: attempting to create resource
CustomResourceDefinition/downloadrequests.velero.io: created
CustomResourceDefinition/podvolumebackups.velero.io: attempting to create resource
CustomResourceDefinition/podvolumebackups.velero.io: created
CustomResourceDefinition/podvolumerestores.velero.io: attempting to create resource
CustomResourceDefinition/podvolumerestores.velero.io: created
CustomResourceDefinition/resticrepositories.velero.io: attempting to create resource
CustomResourceDefinition/resticrepositories.velero.io: created
CustomResourceDefinition/restores.velero.io: attempting to create resource
CustomResourceDefinition/restores.velero.io: created
CustomResourceDefinition/schedules.velero.io: attempting to create resource
CustomResourceDefinition/schedules.velero.io: created
CustomResourceDefinition/serverstatusrequests.velero.io: attempting to create resource
CustomResourceDefinition/serverstatusrequests.velero.io: created
CustomResourceDefinition/volumesnapshotlocations.velero.io: attempting to create resource
CustomResourceDefinition/volumesnapshotlocations.velero.io: created
Waiting for resources to be ready in cluster...
Namespace/velero: attempting to create resource
Namespace/velero: created
ClusterRoleBinding/velero: attempting to create resource
ClusterRoleBinding/velero: created
ServiceAccount/velero: attempting to create resource
ServiceAccount/velero: created
Secret/cloud-credentials: attempting to create resource
Secret/cloud-credentials: created
BackupStorageLocation/default: attempting to create resource
BackupStorageLocation/default: created
VolumeSnapshotLocation/default: attempting to create resource
VolumeSnapshotLocation/default: created
Deployment/velero: attempting to create resource
Deployment/velero: created
DaemonSet/restic: attempting to create resource
DaemonSet/restic: created
Velero is installed!  Use 'kubectl logs deployment/velero -n velero' to view the status.

  8. (openshift) 将velero ServiceAccount添加到privilegedSCC：

    $ oc adm policy add-scc-to-user privileged -z velero -n velero

  9. (openshift) 对于OpenShift版本> = 4.1，修改DaemonSet yaml以请求privileged模式：

    @@ -67,3 +67,5 @@ spec:
              value: /credentials/cloud
            - name: VELERO_SCRATCH_DIR
              value: /scratch
+          securityContext:
+            privileged: true

    或:

    oc patch ds/restic \
  --namespace velero \
  --type json \
  -p '[{"op":"add","path":"/spec/template/spec/containers/0/securityContext","value": { "privileged": true}}]'

备份集群级别的特定资源

velero backup create <backup-name> --include-cluster-resources=true  --include-resources deployments,configmaps

查看备份

velero backup describe YOUR_BACKUP_NAME

备份特定 namespace caseycui2020

排除特定资源

标签为velero.io/exclude-from-backup=true的资源不包括在备份中，即使它包含匹配的选择器标签也是如此。

通过这种方式, 不需要备份的secret 等资源通过velero.io/exclude-from-backup=true 标签(label)进行排除.

通过这种方式排除的secret部分示例如下:

builder-dockercfg-jbnzr
default-token-lshh8
pipeline-token-xt645

使用restic 备份Pod Volume

注意:

该 namespace 下, 以下2个pod volume也需要备份, 但是目前还没正式使用:

  • mycoreapphttptask-callback
  • mycoreapphttptaskservice-callback

通过 "选择性启用" 的方式进行有选择地备份.

  1. 对包含要备份的卷的每个Pod运行以下命令：

    oc -n caseycui2020 annotate pod/<mybackendapp-pod-name> backup.velero.io/backup-volumes=jmx-exporter-agent,pinpoint-agent,my-mybackendapp-claim
oc -n caseycui2020 annotate pod/<elitegetrecservice-pod-name> backup.velero.io/backup-volumes=uploadfile

    其中，卷名是容器 spec中卷的名称。

    例如，对于以下pod：

    apiVersion: v1
kind: Pod
metadata:
  name: sample
  namespace: foo
spec:
  containers:
  - image: k8s.gcr.io/test-webserver
    name: test-webserver
    volumeMounts:
    - name: pvc-volume
      mountPath: /volume-1
    - name: emptydir-volume
      mountPath: /volume-2
  volumes:
  - name: pvc-volume
    persistentVolumeClaim:
      claimName: test-volume-claim
  - name: emptydir-volume
    emptyDir: {}

    你应该运行:

    kubectl -n foo annotate pod/sample backup.velero.io/backup-volumes=pvc-volume,emptydir-volume

    如果您使用控制器来管理您的pods，则也可以在pod template spec中提供此批注。

备份及验证

备份namespace及其对象, 以及具有相关annotation的pod volume:

# 生产 namespace
velero backup create caseycui2020 --include-namespaces caseycui2020

查看备份

velero backup describe YOUR_BACKUP_NAME
velero backup logs caseycui2020
oc -n velero get podvolumebackups -l velero.io/backup-name=caseycui2020 -o yaml

describe查看的结果如下:

Name:         caseycui2020
Namespace:    velero
Labels:       velero.io/storage-location=default
Annotations:  velero.io/source-cluster-k8s-gitversion=v1.18.3+2cf11e2
              velero.io/source-cluster-k8s-major-version=1
              velero.io/source-cluster-k8s-minor-version=18+

Phase:  Completed

Errors:    0
Warnimybackendapp:  0

Namespaces:
  Included:  caseycui2020
  Excluded:  <none>

Resources:
  Included:        *
  Excluded:        <none>
  Cluster-scoped:  auto

Label selector:  <none>

Storage Location:  default

Velero-Native Snapshot PVs:  auto

TTL:  720h0m0s

Hooks:  <none>

Backup Format Version:  1.1.0

Started:    2020-10-21 09:28:16 +0800 CST
Completed:  2020-10-21 09:29:17 +0800 CST

Expiration:  2020-11-20 09:28:16 +0800 CST

Total items to be backed up:  591
Items backed up:              591

Velero-Native Snapshots: <none included>

Restic Backups (specify --details for more information):
  Completed:  3

定期备份

使用基于cron表达式创建定期计划的备份：

velero schedule create caseycui2020-b-daily --schedule="0 3 * * *" --include-namespaces caseycui2020

另外，您可以使用一些非标准的速记cron表达式：

velero schedule create test-daily --schedule="@every 24h" --include-namespaces caseycui2020

有关更多用法示例，请参见cron软件包的文档。

使用 Backups 和 Restores

只要您将每个Velero实例指向相同的云对象存储位置，Velero就能帮助您将资源从一个群集移植到另一个群集。 此方案假定您的群集由同一云提供商托管。 请注意，Velero本身不支持跨云提供程序迁移持久卷快照。 如果要在云平台之间迁移卷数据，请启用restic，它将在文件系统级别备份卷内容。

  1. （集群 B）假设您尚未使用Velero schedule 操作对数据进行检查点检查，则需要首先备份整个群集（根据需要替换<BACKUP-NAME>）：

    velero backup create <BACKUP-NAME>

    默认备份保留期限以TTL（有效期）表示，为30天（720小时）； 您可以使用--ttl <DURATION>标志根据需要进行更改。 有关备份到期的更多信息，请参见velero的工作原理。

  2. （集群 A）配置BackupStorageLocations和VolumeSnapshotLocations, 指向 集群1 使用的位置, 使用velero backup-location create和velero snapshot-location create. 要确保配置BackupStorageLocations为 read-only, 通过在velero backup-location create时使用--access-mode=ReadOnly flag (因为我就只有一个bucket, 所以就没有配置只读这一项). 如下为在A集群安装, 安装时已配置了BackupStorageLocations和VolumeSnapshotLocations.

    velero install \
    --provider aws \
    --plugins velero/velero-plugin-for-aws:v1.0.0 \
    --bucket velero \
    --secret-file ./credentials-velero \
    --use-restic \
    --use-volume-snapshots=true \
    --backup-location-config region="default",s3ForcePathStyle="true",s3Url="http://glacier.ewhisper.cn",insecureSkipTLSVerify="true",signatureVersion="4"\
    --snapshot-location-config region="default"

  3. （集群A）确保已创建Velero Backup对象。 Velero资源与云存储中的备份文件同步。

    velero backup describe <BACKUP-NAME>

    注意：默认同步间隔为1分钟，因此请确保在检查之前等待。 您可以使用Velero服务器的--backup-sync-period标志配置此间隔。

  4. （集群A）一旦确认现在存在正确的备份（<BACKUP-NAME>），就可以使用以下方法还原所有内容： (因为backup 中只有caseycui2020一个 namespace , 所以还原是就不需要--include-namespaces caseycui2020 进行过滤)

    velero restore create --from-backup caseycui2020 --include-resources buildconfigs.build.openshift.io,configmaps,deploymentconfigs.apps.openshift.io,imagestreams.image.openshift.io,imagestreamtags.image.openshift.io,imagetags.image.openshift.io,limitranges,namespaces,networkpolicies.networking.k8s.io,persistentvolumeclaims,prometheusrules.monitoring.coreos.com,resourcequotas,rolebindimybackendapp.authorization.openshift.io,rolebindimybackendapp.rbac.authorization.k8s.io,routes.route.openshift.io,secrets,servicemonitors.monitoring.coreos.com,services,templateinstances.template.openshift.io

    因为后面验证persistentvolumeclaims的restore有问题, 所以后续使用的时候先拿掉这个pvc, 后面再想办法解决:

    velero restore create --from-backup caseycui2020 --include-resources buildconfigs.build.openshift.io,configmaps,deploymentconfigs.apps.openshift.io,imagestreams.image.openshift.io,imagestreamtags.image.openshift.io,imagetags.image.openshift.io,limitranges,namespaces,networkpolicies.networking.k8s.io,persistentvolumeclaims,prometheusrules.monitoring.coreos.com,resourcequotas,rolebindimybackendapp.authorization.openshift.io,rolebindimybackendapp.rbac.authorization.k8s.io,routes.route.openshift.io,secrets,servicemonitors.monitoring.coreos.com,services,templateinstances.template.openshift.io

检查第二个群集是否按预期运行：

  1. (集群A)运行:

    velero restore get

    结果如下:

    NAME                       BACKUP      STATUS            STARTED   COMPLETED   ERRORS   WARNImybackendapp   CREATED                         SELECTOR
caseycui2020-20201021102342   caseycui2020   Failed            <nil>     <nil>       0        0          2020-10-21 10:24:14 +0800 CST   <none>
caseycui2020-20201021103040   caseycui2020   PartiallyFailed   <nil>     <nil>       46       34         2020-10-21 10:31:12 +0800 CST   <none>
caseycui2020-20201021105848   caseycui2020   InProgress        <nil>     <nil>       0        0          2020-10-21 10:59:20 +0800 CST   <none>

  2. 然后运行:

    velero restore describe <RESTORE-NAME-FROM-GET-COMMAND>
oc -n velero get podvolumerestores -l velero.io/restore-name=YOUR_RESTORE_NAME -o yaml

    结果如下:

    Name:         caseycui2020-20201021102342
Namespace:    velero
Labels:       <none>
Annotations:  <none>

Phase:  InProgress

Started:    <n/a>
Completed:  <n/a>

Backup:  caseycui2020

Namespaces:
  Included:  all namespaces found in the backup
  Excluded:  <none>

Resources:
  Included:        buildconfigs.build.openshift.io, configmaps, deploymentconfigs.apps.openshift.io, imagestreams.image.openshift.io, imagestreamtags.image.openshift.io, imagetags.image.openshift.io, limitranges, namespaces, networkpolicies.networking.k8s.io, persistentvolumeclaims, prometheusrules.monitoring.coreos.com, resourcequotas, rolebindimybackendapp.authorization.openshift.io, rolebindimybackendapp.rbac.authorization.k8s.io, routes.route.openshift.io, secrets, servicemonitors.monitoring.coreos.com, services, templateinstances.template.openshift.io
  Excluded:        nodes, events, events.events.k8s.io, backups.velero.io, restores.velero.io, resticrepositories.velero.io
  Cluster-scoped:  auto

Namespace mappimybackendapp:  <none>

Label selector:  <none>

Restore PVs:  auto

如果遇到问题，请确保Velero在两个群集中的相同namespace中运行。

我这边碰到问题, 就是openshift里边, 使用了imagestream和imagetag, 然后对应的镜像拉不过来, 容器没有启动.

容器没有启动, podvolume也没有恢复成功.

Name:         caseycui2020-20201021110424
Namespace:    velero
Labels:       <none>
Annotations:  <none>

Phase:  PartiallyFailed (run 'velero restore logs caseycui2020-20201021110424' for more information)

Started:    <n/a>
Completed:  <n/a>

Warnimybackendapp:
  Velero:     <none>
  Cluster:    <none>
  Namespaces:
    caseycui2020:  could not restore, imagetags.image.openshift.io "mybackendapp:1.0.0" already exists. Warning: the in-cluster version is different than the backed-up version.
                could not restore, imagetags.image.openshift.io "mybackendappno:1.0.0" already exists. Warning: the in-cluster version is different than the backed-up version.
                ...

Errors:
  Velero:     <none>
  Cluster:    <none>
  Namespaces:
    caseycui2020:  error restoring imagestreams.image.openshift.io/caseycui2020/mybackendapp: ImageStream.image.openshift.io "mybackendapp" is invalid: []: Internal error: imagestreams "mybackendapp" is invalid: spec.tags[latest].from.name: Invalid value: "mybackendapp@sha256:6c5ab553a97c74ad602d2427a326124621c163676df91f7040b035fa64b533c7": error generating tag event: imagestreamimage.image.openshift.io ......

Backup:  caseycui2020

Namespaces:
  Included:  all namespaces found in the backup
  Excluded:  <none>

Resources:
  Included:        buildconfigs.build.openshift.io, configmaps, deploymentconfigs.apps.openshift.io, imagestreams.image.openshift.io, imagestreamtags.image.openshift.io, imagetags.image.openshift.io, limitranges, namespaces, networkpolicies.networking.k8s.io, persistentvolumeclaims, prometheusrules.monitoring.coreos.com, resourcequotas, rolebindimybackendapp.authorization.openshift.io, rolebindimybackendapp.rbac.authorization.k8s.io, routes.route.openshift.io, secrets, servicemonitors.monitoring.coreos.com, services, templateinstances.template.openshift.io
  Excluded:        nodes, events, events.events.k8s.io, backups.velero.io, restores.velero.io, resticrepositories.velero.io
  Cluster-scoped:  auto

Namespace mappimybackendapp:  <none>

Label selector:  <none>

Restore PVs:  auto

迁移问题总结

目前总结问题如下:

  1. imagestreams.image.openshift.io, imagestreamtags.image.openshift.io, imagetags.image.openshift.io 里的镜像没有成功导入; 确切地说是latest这个tag没有导入成功. imagestreamtags.image.openshift.io生效也需要时间.

  2. persistentvolumeclaims 迁移过来后报错, 报错如下:

    phase: Lost

    原因是: A B集群的StorageClass的配置是不同的, 所以B集群的PVC, 在A集群想要直接binding是不可能的. 而且创建后无法直接修改, 需要删掉重新创建.

  3. Routes 域名, 有部分域名是特定于A B集群的域名, 如: jenkins-caseycui2020.b.caas.ewhisper.cn迁移到A集群调整为: jenkins-caseycui2020.a.caas.ewhisper.cn

  4. podVolume 数据没有迁移.

latest这个tag没有导入成功

手动导入, 命令如下: (1.0.1 为ImageStream的最新的版本)

oc tag xxl-job-admin:1.0.1 xxl-job-admin:latest

PVC phase Lost问题

如果手动创建, 需要对PVC yaml进行调整. 调整前后PVC如下:

B集群原YAML:

kind: PersistentVolumeClaim
apiVersion: v1
metadata:
  annotations:
    pv.kubernetes.io/bind-completed: 'yes'
    pv.kubernetes.io/bound-by-controller: 'yes'
    volume.beta.kubernetes.io/storage-provisioner: csi.trident.netapp.io
  selfLink: /api/v1/namespaces/caseycui2020/persistentvolumeclaims/jenkins
  resourceVersion: '77304786'
  name: jenkins
  uid: ffcabc42-845d-4cdf-8c7c-56e97cb5ea82
  creationTimestamp: '2020-10-21T03:05:46Z'
  managedFields:
    - manager: kube-controller-manager
      operation: Update
      apiVersion: v1
      time: '2020-10-21T03:05:46Z'
      fieldsType: FieldsV1
      fieldsV1:
        'f:status':
          'f:phase': {}
    - manager: velero-server
      operation: Update
      apiVersion: v1
      time: '2020-10-21T03:05:46Z'
      fieldsType: FieldsV1
      fieldsV1:
        'f:metadata':
          'f:annotations':
            .: {}
            'f:pv.kubernetes.io/bind-completed': {}
            'f:pv.kubernetes.io/bound-by-controller': {}
            'f:volume.beta.kubernetes.io/storage-provisioner': {}
          'f:labels':
            .: {}
            'f:app': {}
            'f:template': {}
            'f:template.openshift.io/template-instance-owner': {}
            'f:velero.io/backup-name': {}
            'f:velero.io/restore-name': {}
        'f:spec':
          'f:accessModes': {}
          'f:resources':
            'f:requests':
              .: {}
              'f:storage': {}
          'f:storageClassName': {}
          'f:volumeMode': {}
          'f:volumeName': {}
  namespace: caseycui2020
  finalizers:
    - kubernetes.io/pvc-protection
  labels:
    app: jenkins-persistent
    template: jenkins-persistent-monitored
    template.openshift.io/template-instance-owner: 5a0b28c3-c760-451b-b92f-a781406d9e91
    velero.io/backup-name: caseycui2020
    velero.io/restore-name: caseycui2020-20201021110424
spec:
  accessModes:
    - ReadWriteOnce
  resources:
    requests:
      storage: 5Gi
  volumeName: pvc-414efafd-8b22-48da-8c20-6025a8e671ca
  storageClassName: nas-data
  volumeMode: Filesystem
status:
  phase: Lost

调整后:

kind: PersistentVolumeClaim
apiVersion: v1
metadata:
  name: jenkins
  namespace: caseycui2020
  labels:
    app: jenkins-persistent
    template: jenkins-persistent-monitored
    template.openshift.io/template-instance-owner: 5a0b28c3-c760-451b-b92f-a781406d9e91
spec:
  accessModes:
    - ReadWriteOnce
  resources:
    requests:
      storage: 5Gi
  storageClassName: nas-data
  volumeMode: Filesystem

podVolume 数据没有迁移

可以手动迁移, 命令如下:

# 登录B集群
# 先把B 集群/opt/prometheus数据拿出来到当前文件夹
oc rsync xxl-job-admin-5-9sgf7:/opt/prometheus .
# 上边rsync命令会创建个prometheus的目录
cd prometheus
# 登录A集群
# 再把数据拷贝进去(拷贝之前得先确保这个pod启动起来) (可以先把`JAVA_OPTS`删掉)
oc rsync ./ xxl-job-admin-2-6k8df:/opt/prometheus/

本文写的比较早, 后面 OpenShift 出了基于 Velero 封装的 OpenShift 专有的迁移工具, 可以直接通过它提供的工具进行迁移.

另外, OpenShift 集群上限制很多, 另外也有很多专属于 OpenShift 的资源, 所以在实际使用上和标准 K8S 的差别还是比较大的, 需要仔细注意.

本次虽然尝试失败, 但是其中的思路还是可供借鉴的.

三人行, 必有我师; 知识共享, 天下为公. 本文由东风微鸣技术博客 EWhisper.cn 编写.

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