kubernetes 学习笔记3

kubernetes  自动发布和回滚

deployment 引入的目的是为了更好的解决pod的编排问题。

 

• 创建一个deployment对象来生成对应的replica set 并完成 pod副本的创建过程
• 检查deployment的状态来看部署动作是否完成（pod副本的数量是否达到预期的值）
• 更新deployment以创建新的pod（比如镜像升级）
• 如果当前deployment不稳定，则回滚至一个早先的deployment版本

创建deployment

$ kubectl create -f docs/user-guide/nginx-deployment.yaml --record
deployment "nginx-deployment” created

查看正在创建或者正在更新的deplyment

$ kubectl get deployments
NAME               DESIRED   CURRENT   UP-TO-DATE   AVAILABLE   AGE
nginx-deployment   3         0         0            0           1s

$ kubectl get deployments
NAME               DESIRED   CURRENT   UP-TO-DATE   AVAILABLE   AGE
nginx-deployment   3         3         3            3           18s

查看replica set 和 pod

$ kubectl get rs
NAME                          DESIRED   CURRENT   AGE
nginx-deployment-2035384211   3         3         18s 

查看生成的各个pod的归属关系

$ kubectl get pods --show-labels
NAME                                READY     STATUS    RESTARTS   AGE       LABELS
nginx-deployment-2035384211-7ci7o   1/1       Running   0          18s       app=nginx,pod-template-hash=2035384211
nginx-deployment-2035384211-kzszj   1/1       Running   0          18s       app=nginx,pod-template-hash=2035384211
nginx-deployment-2035384211-qqcnn   1/1       Running   0          18s       app=nginx,pod-template-hash=2035384211

查看deployment的状态

$ kubectl rollout status deployment/nginx-deployment
deployment "nginx-deployment" successfully rolled out

更新deployment

 

当deployment 里面的pod模版更改了

                         label更新了

                         容器镜像改变了，那么会触发deployment重新发布，如果deployment进行扩展，那么不会触发deployment

 

可以直接写命令进行更改

kubectl set image deployment/nginx-deployment nginx=nginx:1.9.1
deployment "nginx-deployment" image updated

也可以进行编辑进行更改

$ kubectl edit deployment/nginx-deployment
deployment "nginx-deployment" edited

查看发布的状态

$ kubectl rollout status deployment/nginx-deployment
Waiting for rollout to finish: 2 out of 3 new replicas have been updated...
deployment "nginx-deployment" successfully rolled out

如果发布成功

$ kubectl get deployments
NAME               DESIRED   CURRENT   UP-TO-DATE   AVAILABLE   AGE
nginx-deployment   3         3         3            3           36s

$ kubectl get rs
NAME                          DESIRED   CURRENT   AGE
nginx-deployment-1564180365   3         3         6s
nginx-deployment-2035384211   0         0         36s

$ kubectl get pods
NAME                                READY     STATUS    RESTARTS   AGE
nginx-deployment-1564180365-khku8   1/1       Running   0          14s
nginx-deployment-1564180365-nacti   1/1       Running   0          14s
nginx-deployment-1564180365-z9gth   1/1       Running   0          14s

更新pod，我们只需更新deployment里面的templement

当我们更新deployment时候，当有合适的pod产生的时候，k8s才会删除老的pod，当老的pod被删除足够多时，才会继续产生新的pod

 

 

deployment 回滚

查看deployment详细信息

$ kubectl describe deployment

查看deployment的发布历史

$ kubectl rollout history deployment/nginx-deployment

可以回滚至任一个之前的版本

$ kubectl rollout undo deployment/nginx-deployment
deployment "nginx-deployment" rolled back

$ kubectl rollout undo deployment/nginx-deployment --to-revision=2
deployment "nginx-deployment" rolled back

扩展deployment

ou can scale a Deployment by using the following command:

$ kubectl scale deployment nginx-deployment --replicas 10
deployment "nginx-deployment" scaled

$ kubectl autoscale deployment nginx-deployment --min=10 --max=15 --cpu-percent=80
deployment "nginx-deployment" autoscaled

暂停或者回复一个deployment

$ kubectl set image deployment/nginx-deployment nginx=nginx:1.9.1; kubectl rollout pause deployment/nginx-deployment
deployment "nginx-deployment" image updated
deployment "nginx-deployment" paused

deployment的状态

deployment为processing状态的情况为：

1.deployment正在创建rs

2.deployment正在扩展或者删除rs

 

deploymen为什么会失败

• Insufficient quota
• Readiness probe failures
• Image pull errors
• Insufficient permissions
• Limit ranges
• Application runtime misconfiguration