kubernetes 學習筆記3

kubernetes  自動發佈和回滾

deployment 引入的目的是爲了更好的解決pod的編排問題。

 

• 建立一個deployment對象來生成對應的replica set 並完成 pod副本的建立過程
• 檢查deployment的狀態來看部署動做是否完成（pod副本的數量是否達到預期的值）
• 更新deployment以建立新的pod（好比鏡像升級）
• 若是當前deployment不穩定，則回滾至一個早先的deployment版本

建立deployment

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

查看正在建立或者正在更新的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

查看生成的各個pod的歸屬關係

$ 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的狀態

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

更新deployment

 

當deployment 裏面的pod模版更改了

                         label更新了

                         容器鏡像改變了，那麼會觸發deployment從新發布，若是deployment進行擴展，那麼不會觸發deployment

 

能夠直接寫命令進行更改

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

也能夠進行編輯進行更改

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

查看發佈的狀態

$ 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

若是發佈成功

$ 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，咱們只需更新deployment裏面的templement

當咱們更新deployment時候，當有合適的pod產生的時候，k8s纔會刪除老的pod，當老的pod被刪除足夠多時，纔會繼續產生新的pod

 

 

deployment 回滾

查看deployment詳細信息

$ kubectl describe deployment

查看deployment的發佈歷史

$ kubectl rollout history deployment/nginx-deployment

能夠回滾至任一個以前的版本

$ 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

擴展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

暫停或者回復一個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的狀態

deployment爲processing狀態的狀況爲：

1.deployment正在建立rs

2.deployment正在擴展或者刪除rs

 

deploymen爲何會失敗

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