备份与迁移k8s集群神器

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前言

一般来说大家都用etcd备份恢复k8s集群，但是有时候我们可能不小心删掉了一个namespace，假设这个ns里面有上百个服务，瞬间没了，怎么办？

当然了，可以用CI/CD系统发布，但是时间会花费很久，这时候，vmvare的Velero出现了。

velero可以帮助我们：

  • 灾备场景，提供备份恢复k8s集群的能力
  • 迁移场景，提供拷贝集群资源到其他集群的能力（复制同步开发，测试，生产环境的集群配置，简化环境配置）

下面我就介绍一下如何使用 Velero 完成备份和迁移。

Velero 地址：https://github.com/vmware-tanzu/velero

ACK 插件地址：https://github.com/AliyunContainerService/velero-plugin

下载 Velero 客户端

Velero 由客户端和服务端组成，服务器部署在目标 k8s 集群上，而客户端则是运行在本地的命令行工具。

  • 前往 Velero 的 Release 页面 下载客户端，直接在 GitHub 上下载即可
  • 解压 release 包
  • 将 release 包中的二进制文件 velero 移动到 $PATH 中的某个目录下
  • 执行 velero -h 测试

部署velero-plugin插件

拉取代码

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git clone https://github.com/AliyunContainerService/velero-plugin

配置修改

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#修改 `install/credentials-velero` 文件，将新建用户中获得的 `AccessKeyID` 和 `AccessKeySecret` 填入，这里的 OSS EndPoint 为之前 OSS 的访问域名

ALIBABA_CLOUD_ACCESS_KEY_ID=<ALIBABA_CLOUD_ACCESS_KEY_ID>
ALIBABA_CLOUD_ACCESS_KEY_SECRET=<ALIBABA_CLOUD_ACCESS_KEY_SECRET>
ALIBABA_CLOUD_OSS_ENDPOINT=<ALIBABA_CLOUD_OSS_ENDPOINT>
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#修改 `install/01-velero.yaml`，将 OSS 配置填入：
---
apiVersion: v1
kind: ServiceAccount
metadata:
  namespace: velero
  name: velero

---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  labels:
    component: velero
  name: velero
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: cluster-admin
subjects:
- kind: ServiceAccount
  name: velero
  namespace: velero

---
apiVersion: velero.io/v1
kind: BackupStorageLocation
metadata:
  labels:
    component: velero
  name: default
  namespace: velero
spec:
  config:
    region: cn-beijing
  objectStorage:
    bucket: k8s-backup-test
    prefix: test
  provider: alibabacloud

---
apiVersion: velero.io/v1
kind: VolumeSnapshotLocation
metadata:
  labels:
    component: velero
  name: default
  namespace: velero
spec:
  config:
    region: cn-beijing
  provider: alibabacloud

---
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name: velero
  namespace: velero
spec:
  replicas: 1
  selector:
    matchLabels:
      deploy: velero
  template:
    metadata:
      annotations:
        prometheus.io/path: /metrics
        prometheus.io/port: "8085"
        prometheus.io/scrape: "true"
      labels:
        component: velero
        deploy: velero
    spec:
      serviceAccountName: velero
      containers:
      - name: velero
        # sync from velero/velero:v1.2.0
        image: registry.cn-hangzhou.aliyuncs.com/acs/velero:v1.2.0
        imagePullPolicy: IfNotPresent
        command:
          - /velero
        args:
          - server
          - --default-volume-snapshot-locations=alibabacloud:default
        env:
          - name: VELERO_SCRATCH_DIR
            value: /scratch
          - name: ALIBABA_CLOUD_CREDENTIALS_FILE
            value: /credentials/cloud
        volumeMounts:
          - mountPath: /plugins
            name: plugins
          - mountPath: /scratch
            name: scratch
          - mountPath: /credentials
            name: cloud-credentials
      initContainers:
      - image: registry.cn-hangzhou.aliyuncs.com/acs/velero-plugin-alibabacloud:v1.2-991b590
        imagePullPolicy: IfNotPresent
        name: velero-plugin-alibabacloud
        volumeMounts:
        - mountPath: /target
          name: plugins
      volumes:
        - emptyDir: {}
          name: plugins
        - emptyDir: {}
          name: scratch
        - name: cloud-credentials
          secret:
            secretName: cloud-credentials

k8s 部署 Velero 服务

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# 新建 namespace
kubectl create namespace velero
# 部署 credentials-velero 的 secret
kubectl create secret generic cloud-credentials --namespace velero --from-file cloud=install/credentials-velero
# 部署 CRD
kubectl apply -f install/00-crds.yaml
# 部署 Velero
kubectl apply -f install/01-velero.yaml

备份测试

这里，我们将使用velero备份一个集群内相关的resource，并在当该集群出现一些故障或误操作的时候，能够快速恢复集群resource， 首先我们用下面的yaml来部署： 

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---
apiVersion: v1
kind: Namespace
metadata:
  name: nginx-example
  labels:
    app: nginx

---
apiVersion: apps/v1beta1
kind: Deployment
metadata:
  name: nginx-deployment
  namespace: nginx-example
spec:
  replicas: 2
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
      - image: nginx:1.7.9
        name: nginx
        ports:
        - containerPort: 80

---
apiVersion: v1
kind: Service
metadata:
  labels:
    app: nginx
  name: my-nginx
  namespace: nginx-example
spec:
  ports:
  - port: 80
    targetPort: 80
  selector:
    app: nginx

我们可以全量备份，也可以只备份需要备份的一个namespace，本处只备份一个namespace：nginx-example

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[rsync@velero-plugin]$ kubectl get pods -n nginx-example
NAME                                READY   STATUS    RESTARTS   AGE
nginx-deployment-5c689d88bb-f8vsx   1/1     Running   0          6m31s
nginx-deployment-5c689d88bb-rt2zk   1/1     Running   0          6m32s		
		
[rsync@velero]$ cd velero-v1.4.0-linux-amd64/
[rsync@velero-v1.4.0-linux-amd64]$ ll
total 56472
drwxrwxr-x 4 rsync rsync     4096 Jun  1 15:02 examples
-rw-r--r-- 1 rsync rsync    10255 Dec 10 01:08 LICENSE
-rwxr-xr-x 1 rsync rsync 57810814 May 27 04:33 velero
[rsync@velero-v1.4.0-linux-amd64]$ ./velero backup create nginx-backup --include-namespaces nginx-example --wait
Backup request "nginx-backup" submitted successfully.
Waiting for backup to complete. You may safely press ctrl-c to stop waiting - your backup will continue in the background.
.
Backup completed with status: Completed. You may check for more information using the commands `velero backup describe nginx-backup` and `velero backup logs nginx-backup`.

删除ns

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[rsync@velero-v1.4.0-linux-amd64]$ kubectl delete namespaces nginx-example
namespace "nginx-example" deleted

[rsync@velero-v1.4.0-linux-amd64]$ kubectl get pods -n nginx-example  
No resources found.

恢复

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[rsync@velero-v1.4.0-linux-amd64]$ ./velero restore create --from-backup nginx-backup --wait
Restore request "nginx-backup-20200603180922" submitted successfully.
Waiting for restore to complete. You may safely press ctrl-c to stop waiting - your restore will continue in the background.

Restore completed with status: Completed. You may check for more information using the commands `velero restore describe nginx-backup-20200603180922` and `velero restore logs nginx-backup-20200603180922`.
[rsync@velero-v1.4.0-linux-amd64]$ kubectl get pods -n nginx-example
NAME                                READY   STATUS              RESTARTS   AGE
nginx-deployment-5c689d88bb-f8vsx   1/1     Running             0          5s
nginx-deployment-5c689d88bb-rt2zk   0/1     ContainerCreating   0          5s

可以看到已经恢复了

另外迁移和备份恢复也是一样的，下面看一个特殊的，再部署一个项目，之后恢复会不会删掉新部署的项目。

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新建了一个tomcat容器
[rsync@tomcat-test]$ kubectl get pods -n nginx-example
NAME                                READY   STATUS    RESTARTS   AGE
nginx-deployment-5c689d88bb-f8vsx   1/1     Running   0          65m
nginx-deployment-5c689d88bb-rt2zk   1/1     Running   0          65m
tomcat-test-sy-677ff78f6b-rc5vq     1/1     Running   0          7s

restore 一下

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[rsync@velero-v1.4.0-linux-amd64]$ ./velero  restore create --from-backup nginx-backup        
Restore request "nginx-backup-20200603191726" submitted successfully.
Run `velero restore describe nginx-backup-20200603191726` or `velero restore logs nginx-backup-20200603191726` for more details.
[rsync@velero-v1.4.0-linux-amd64]$ kubectl get pods -n nginx-example  
NAME                                READY   STATUS    RESTARTS   AGE
nginx-deployment-5c689d88bb-f8vsx   1/1     Running   0          68m
nginx-deployment-5c689d88bb-rt2zk   1/1     Running   0          68m
tomcat-test-sy-677ff78f6b-rc5vq     1/1     Running   0          2m33s

可以看到没有覆盖

删除nginx的deployment，在restore

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[rsync@velero-v1.4.0-linux-amd64]$ kubectl delete deployment nginx-deployment -n nginx-example
deployment.extensions "nginx-deployment" deleted

[rsync@velero-v1.4.0-linux-amd64]$ kubectl get pods -n nginx-example
NAME                              READY   STATUS    RESTARTS   AGE
tomcat-test-sy-677ff78f6b-rc5vq   1/1     Running   0          4m18s

[rsync@velero-v1.4.0-linux-amd64]$ ./velero  restore create --from-backup nginx-backup 
Restore request "nginx-backup-20200603191949" submitted successfully.
Run `velero restore describe nginx-backup-20200603191949` or `velero restore logs nginx-backup-20200603191949` for more details.

[rsync@velero-v1.4.0-linux-amd64]$ kubectl get pods -n nginx-example             NAME                                READY   STATUS              RESTARTS   AGE
nginx-deployment-5c689d88bb-f8vsx   1/1     Running             0          2s
nginx-deployment-5c689d88bb-rt2zk   0/1     ContainerCreating   0          2s
tomcat-test-sy-677ff78f6b-rc5vq     1/1     Running             0          4m49s

可以看到，对我们的tomcat项目是没影响的。

结论：velero恢复不是直接覆盖，而是会恢复当前集群中不存在的resource，已有的resource不会回滚到之前的版本，如需要回滚，需在restore之前提前删除现有的resource。

高级用法

可以设置一个周期性定时备份

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# 每日1点进行备份
velero create schedule <SCHEDULE NAME> --schedule="0 1 * * *"
# 每日1点进行备份，备份保留48小时
velero create schedule <SCHEDULE NAME> --schedule="0 1 * * *" --ttl 48h
# 每6小时进行一次备份
velero create schedule <SCHEDULE NAME> --schedule="@every 6h"
# 每日对 web namespace 进行一次备份
velero create schedule <SCHEDULE NAME> --schedule="@every 24h" --include-namespaces web
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定时备份的名称为：`<SCHEDULE NAME>-<TIMESTAMP>`，恢复命令为：`velero restore create --from-backup <SCHEDULE NAME>-<TIMESTAMP>`。

如需备份恢复持久卷，备份如下：

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velero backup create nginx-backup-volume --snapshot-volumes --include-namespaces nginx-example

该备份会在集群所在region给云盘创建快照（当前还不支持NAS和OSS存储），快照恢复云盘只能在同region完成。

恢复命令如下：

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velero  restore create --from-backup nginx-backup-volume --restore-volumes

删除备份

  1. 方法一，通过命令直接删除
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velero delete backups default-backup
  1. 方法二，设置备份自动过期，在创建备份时，加上TTL参数
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velero backup create <BACKUP-NAME> --ttl <DURATION>

还可为资源添加指定标签，添加标签的资源在备份的时候被排除。

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# 添加标签
kubectl label -n <ITEM_NAMESPACE> <RESOURCE>/<NAME> velero.io/exclude-from-backup=true
# 为 default namespace 添加标签
kubectl label -n default namespace/default velero.io/exclude-from-backup=true

参考链接

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