当前状态
先看deployment
root@k8s-master:~# kubectl get deploy -o wide --show-labels
NAME READY UP-TO-DATE AVAILABLE AGE CONTAINERS IMAGES SELECTOR LABELS
bq-api-service-deploy-sample 5/5 5 5 4h47m bq-api-service-container europe-west2-docker.pkg.dev/jason-hsbc/my-docker-repo/bq-api-service:1.1.3 app=bq-api-service app=bq-api-service,author=Jason
root@k8s-master:~#
得知 这个deployment 的image 版本是1.1.3 ， 有5个运行副本
查看revisions 历史
root@k8s-master:~# kubectl rollout history deployment/bq-api-service-deploy-sample
deployment.apps/bq-api-service-deploy-sample
REVISION CHANGE-CAUSE
1 <none>
2 <none>
3 <none>
可以见到有3个revisions
其实他们对应的是image 版本1.1.1 ， 1.1.2 和 1.1.3
至于k8s 会为1个deployment 保留多少个revisions, 是由参数spec.revisionHistoryLimit 决定的
例如 下面配置意思就是期望运行5个pod 副本， 但是会保留pod 的10个历史版本
spec:replicas: 10 # desired replica count, Please note that the replica Pods in a Deployment are typically distributed across multiple nodes.revisionHistoryLimit: 10
查看ReplicaSet 信息
root@k8s-master:~# kubectl get rs -o wide -l app=bq-api-service
NAME DESIRED CURRENT READY AGE CONTAINERS IMAGES SELECTOR
bq-api-service-deploy-sample-7bff8fbc4b 5 5 5 81m bq-api-service-container europe-west2-docker.pkg.dev/jason-hsbc/my-docker-repo/bq-api-service:1.1.3 app=bq-api-service,pod-template-hash=7bff8fbc4b
bq-api-service-deploy-sample-8d49d9845 0 0 0 88m bq-api-service-container europe-west2-docker.pkg.dev/jason-hsbc/my-docker-repo/bq-api-service:1.1.2 app=bq-api-service,pod-template-hash=8d49d9845
bq-api-service-deploy-sample-9f8d9c988 0 0 0 5h23m bq-api-service-container europe-west2-docker.pkg.dev/jason-hsbc/my-docker-repo/bq-api-service:1.1.1 app=bq-api-service,pod-template-hash=9f8d9c988
root@k8s-master:~#
刚好也是3个rs, 其实他们刚好对应了3个revisions的image 版本
只不过1.1.3 版本的RS 有5个当前运行的POD 副本， 而1.1.1 和 1.1.2 的副本数量是0, 符合常规.
但是 ReplicaSet 和 Revision 不是永远可以一一对应的， 一是revisions数量有限制， 二是1个deployment 的replicaSet 有可能会被重用
查看Pod 信息
root@k8s-master:~# kubectl get po -o wide -l app=bq-api-service
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
bq-api-service-deploy-sample-7bff8fbc4b-b9c8v 1/1 Running 0 92m 10.244.3.40 k8s-node3 <none> <none>
bq-api-service-deploy-sample-7bff8fbc4b-bf8bp 1/1 Running 0 92m 10.244.1.29 k8s-node1 <none> <none>
bq-api-service-deploy-sample-7bff8fbc4b-hqfmw 1/1 Running 0 92m 10.244.1.30 k8s-node1 <none> <none>
bq-api-service-deploy-sample-7bff8fbc4b-lgjj9 1/1 Running 0 92m 10.244.2.91 k8s-node0 <none> <none>
bq-api-service-deploy-sample-7bff8fbc4b-wgrj5 1/1 Running 0 92m 10.244.2.89 k8s-node0 <none> <none>
有5个pod 正在运行， 关键pod 名字是包含了 rs 的对象名字的
如
bq-api-service-deploy-sample-7bff8fbc4b-b9c8v
所以我们可以用pod 的名字来知道它是属于哪个 ReplicaSet的
用新的部署来实现回滚到1.1.2 版本
回滚1个service 的版本有多种方法
- 是部署多一次旧的image 版本
- 恢复已备份的service版本
在生产中， 我们可能会更常用第一种
这里我们也试试
方法很简单， 在上一篇文章介绍过来
用kubectl set image 命令来实现
kubectl set image deployment/<deployment_name> <container_name>=europe-west2-docker.pkg.dev/jason-hsbc/my-docker-repo/bq-api-service:<新版本号>
root@k8s-master:~# kubectl set image deployment/bq-api-service-deploy-sample bq-api-service-container=europe-west2-docker.pkg.dev/jason-hsbc/my-docker-repo/bq-api-service:1.1.2
deployment.apps/bq-api-service-deploy-sample image updated
更新回1.1.2 版本
root@k8s-master:~# kubectl get deploy -o wide --show-labels
NAME READY UP-TO-DATE AVAILABLE AGE CONTAINERS IMAGES SELECTOR LABELS
bq-api-service-deploy-sample 5/5 5 5 5h53m bq-api-service-container europe-west2-docker.pkg.dev/jason-hsbc/my-docker-repo/bq-api-service:1.1.2 app=bq-api-service app=bq-api-service,author=Jason
检查rs
root@k8s-master:~# kubectl get rs -o wide -l app=bq-api-service
NAME DESIRED CURRENT READY AGE CONTAINERS IMAGES SELECTOR
bq-api-service-deploy-sample-7bff8fbc4b 0 0 0 111m bq-api-service-container europe-west2-docker.pkg.dev/jason-hsbc/my-docker-repo/bq-api-service:1.1.3 app=bq-api-service,pod-template-hash=7bff8fbc4b
bq-api-service-deploy-sample-8d49d9845 5 5 5 119m bq-api-service-container europe-west2-docker.pkg.dev/jason-hsbc/my-docker-repo/bq-api-service:1.1.2 app=bq-api-service,pod-template-hash=8d49d9845
bq-api-service-deploy-sample-9f8d9c988 0 0 0 5h53m bq-api-service-container europe-west2-docker.pkg.dev/jason-hsbc/my-docker-repo/bq-api-service:1.1.1 app=bq-api-service,pod-template-hash=9f8d9c988
更新回之前的版本， 与一般的更新不同， 因为之前已经有1个RS 是for image 1.1.2的所以这次k8s 重用了之前的rs而并没有增加1个
查看deployment event
kubectl describe deployment bq-api-service-deploy-sample
Events:Type Reason Age From Message---- ------ ---- ---- -------Normal ScalingReplicaSet 12m (x2 over 131m) deployment-controller Scaled up replica set bq-api-service-deploy-sample-8d49d9845 to 3Normal ScalingReplicaSet 12m deployment-controller Scaled up replica set bq-api-service-deploy-sample-8d49d9845 to 2Normal ScalingReplicaSet 12m deployment-controller Scaled down replica set bq-api-service-deploy-sample-7bff8fbc4b to 4Normal ScalingReplicaSet 12m deployment-controller Scaled down replica set bq-api-service-deploy-sample-7bff8fbc4b to 3Normal ScalingReplicaSet 12m deployment-controller Scaled up replica set bq-api-service-deploy-sample-8d49d9845 to 4Normal ScalingReplicaSet 12m deployment-controller Scaled down replica set bq-api-service-deploy-sample-7bff8fbc4b to 2Normal ScalingReplicaSet 12m deployment-controller Scaled up replica set bq-api-service-deploy-sample-8d49d9845 to 5Normal ScalingReplicaSet 12m deployment-controller Scaled down replica set bq-api-service-deploy-sample-7bff8fbc4b to 1Normal ScalingReplicaSet 12m deployment-controller Scaled down replica set bq-api-service-deploy-sample-7bff8fbc4b to 0
可以看到回滚的实现就是无非把1.1.2的rs 里的pod副本逐渐增加到5, 而1.1.3 rs的pod副本从5 减少到0
查看revisions
root@k8s-master:~# kubectl rollout history deployment/bq-api-service-deploy-sample
deployment.apps/bq-api-service-deploy-sample
REVISION CHANGE-CAUSE
1 <none>
3 <none>
4 <none>
并我预想中的 1, 2,3 变成 1,2,3,4 而是把2删除了
用恢复备份的方法来回到1.1.1 版本
上面的方法其实有限制的， 前提就是 1.1.2的镜像还在server or GAR里存在
而用恢复备份的方法并没有限制
命令:
kubectl rollout undo deployment/deployment_name --to-revision=x x就是revisions 数字
如果不提供x 则默认回滚到上1个版本 (本文例子是1.1.3）
执行
root@k8s-master:~# kubectl rollout undo deployment/bq-api-service-deploy-sample --to-revision=1
deployment.apps/bq-api-service-deploy-sample rolled back
执行成功， 而且提示是rolled back
检查deployment
版本已经恢复到1.1.1
root@k8s-master:~# kubectl get deploy -o wide --show-labels
NAME READY UP-TO-DATE AVAILABLE AGE CONTAINERS IMAGES SELECTOR LABELS
bq-api-service-deploy-sample 5/5 5 5 6h12m bq-api-service-container europe-west2-docker.pkg.dev/jason-hsbc/my-docker-repo/bq-api-service:1.1.1 app=bq-api-service app=bq-api-service,author=Jason
root@k8s-master:~#
检查rs
同样这种方法也能重用之前的rs (1.1.1 版本）
root@k8s-master:~# kubectl get rs -o wide -l app=bq-api-service
NAME DESIRED CURRENT READY AGE CONTAINERS IMAGES SELECTOR
bq-api-service-deploy-sample-7bff8fbc4b 0 0 0 131m bq-api-service-container europe-west2-docker.pkg.dev/jason-hsbc/my-docker-repo/bq-api-service:1.1.3 app=bq-api-service,pod-template-hash=7bff8fbc4b
bq-api-service-deploy-sample-8d49d9845 0 0 0 138m bq-api-service-container europe-west2-docker.pkg.dev/jason-hsbc/my-docker-repo/bq-api-service:1.1.2 app=bq-api-service,pod-template-hash=8d49d9845
bq-api-service-deploy-sample-9f8d9c988 5 5 5 6h13m bq-api-service-container europe-west2-docker.pkg.dev/jason-hsbc/my-docker-repo/bq-api-service:1.1.1 app=bq-api-service,pod-template-hash=9f8d9c988
root@k8s-master:~#
查看revisions
root@k8s-master:~# kubectl rollout history deployment/bq-api-service-deploy-sample
deployment.apps/bq-api-service-deploy-sample
REVISION CHANGE-CAUSE
3 <none>
4 <none>
5 <none>
变成了 3,4,5 其实就是1变成5
查看deployment event
kubectl describe deployment bq-api-service-deploy-sample
Normal ScalingReplicaSet 2m54s deployment-controller Scaled down replica set bq-api-service-deploy-sample-8d49d9845 to 4Normal ScalingReplicaSet 2m54s deployment-controller Scaled up replica set bq-api-service-deploy-sample-9f8d9c988 to 2Normal ScalingReplicaSet 2m53s deployment-controller Scaled down replica set bq-api-service-deploy-sample-8d49d9845 to 3Normal ScalingReplicaSet 2m53s deployment-controller Scaled up replica set bq-api-service-deploy-sample-9f8d9c988 to 4Normal ScalingReplicaSet 2m53s deployment-controller Scaled down replica set bq-api-service-deploy-sample-8d49d9845 to 2Normal ScalingReplicaSet 2m53s deployment-controller Scaled up replica set bq-api-service-deploy-sample-9f8d9c988 to 5Normal ScalingReplicaSet 2m53s deployment-controller Scaled down replica set bq-api-service-deploy-sample-8d49d9845 to 1Normal ScalingReplicaSet 2m52s deployment-controller Scaled down replica set bq-api-service-deploy-sample-8d49d9845 to 0sh一样， 1.1.2 的rs pod 副本数量被scale down ->0 , 1.1.1 的rs pod 副本数量 scale up-> 5
