滚动更新是按照倒序方式进行，可以指定分区号，如指定分区号N，则表示更新序号大于等于N的Pod，默认分区为0，表示更新所有Pod

[root@maxiaoke local-k8s-yaml]# kubectl -n apps set image sts nginx-web nginx-web=linuxmaxiaoke/nginx:v1.0.1
[root@maxiaoke ~]# kubectl get pod -n apps -w  # 注意是倒序更新所有Pod
NAME          READY   STATUS    RESTARTS   AGE
nginx-web-0   1/1     Running   2          10h
nginx-web-1   1/1     Running   2          10h
nginx-web-1   1/1     Terminating   2          10h
nginx-web-1   0/1     Terminating   2          10h
nginx-web-1   0/1     Terminating   2          10h
nginx-web-1   0/1     Terminating   2          10h
nginx-web-1   0/1     Pending       0          0s
nginx-web-1   0/1     Pending       0          0s
nginx-web-1   0/1     ContainerCreating   0          0s
nginx-web-1   0/1     Running             0          22s
nginx-web-1   1/1     Running             0          27s
nginx-web-0   1/1     Terminating         2          10h
nginx-web-0   0/1     Terminating         2          10h
nginx-web-0   0/1     Terminating         2          10h
nginx-web-0   0/1     Terminating         2          10h
nginx-web-0   0/1     Pending             0          0s
nginx-web-0   0/1     Pending             0          0s
nginx-web-0   0/1     ContainerCreating   0          0s
nginx-web-0   0/1     ErrImagePull        0          29s
nginx-web-0   0/1     ImagePullBackOff    0          44s
nginx-web-0   0/1     Running             0          62s
nginx-web-0   1/1     Running             0          70s

[root@maxiaoke local-k8s-yaml]# kubectl -n apps patch sts nginx-web -p '{"spec":{"replicas":5}}' # 扩容到5个副本，方便演示
[root@maxiaoke local-k8s-yaml]# kubectl -n apps patch sts nginx-web -p '{"spec":{"updateStrategy":{"type":"RollingUpdate","rollingUpdate":{"partition":3}}}}' # 指定更新分区为3
[root@maxiaoke local-k8s-yaml]# kubectl -n apps set image sts nginx-web nginx-web=linuxmaxiaoke/nginx:v1.0.2 # 开始更新
[root@maxiaoke ~]# kubectl get pod -n apps -w  # 只更新序号4和3的Pod
NAME          READY   STATUS    RESTARTS   AGE
nginx-web-0   1/1     Running   0          6m31s
nginx-web-1   1/1     Running   0          7m12s
nginx-web-2   1/1     Running   0          3m38s
nginx-web-3   1/1     Running   0          3m33s
nginx-web-4   1/1     Running   0          3m23s
nginx-web-4   1/1     Terminating   0          3m25s
nginx-web-4   0/1     Terminating   0          3m26s
nginx-web-4   0/1     Terminating   0          3m32s
nginx-web-4   0/1     Terminating   0          3m32s
nginx-web-4   0/1     Pending       0          0s
nginx-web-4   0/1     Pending       0          0s
nginx-web-4   0/1     ContainerCreating   0          0s
nginx-web-4   0/1     Running             0          10s
nginx-web-4   1/1     Running             0          17s
nginx-web-3   1/1     Terminating         0          3m59s
nginx-web-3   0/1     Terminating         0          4m
nginx-web-3   0/1     Terminating         0          4m1s
nginx-web-3   0/1     Terminating         0          4m1s
nginx-web-3   0/1     Pending             0          0s
nginx-web-3   0/1     Pending             0          0s
nginx-web-3   0/1     ContainerCreating   0          0s
nginx-web-3   0/1     Running             0          22s
nginx-web-3   1/1     Running             0          25s

[root@maxiaoke local-k8s-yaml]# kubectl -n apps patch sts nginx-web -p '{"spec":{"updateStrategy":{"type":"RollingUpdate","rollingUpdate":{"partition":0}}}}' # 修改分区为0
[root@maxiaoke ~]# kubectl get pod -n apps -w   # 会更新剩下来的三个Pod
NAME          READY   STATUS    RESTARTS   AGE
nginx-web-0   1/1     Running   0          9m10s
nginx-web-1   1/1     Running   0          9m51s
nginx-web-2   1/1     Running   0          6m17s
nginx-web-3   1/1     Running   0          2m11s
nginx-web-4   1/1     Running   0          2m30s
nginx-web-2   1/1     Terminating   0          6m24s
nginx-web-2   0/1     Terminating   0          6m24s
nginx-web-2   0/1     Terminating   0          6m25s
nginx-web-2   0/1     Terminating   0          6m25s
nginx-web-2   0/1     Pending       0          0s
nginx-web-2   0/1     Pending       0          0s
nginx-web-2   0/1     ContainerCreating   0          0s
nginx-web-2   0/1     Running             0          1s
nginx-web-2   1/1     Running             0          9s
nginx-web-1   1/1     Terminating         0          10m
nginx-web-1   0/1     Terminating         0          10m
nginx-web-1   0/1     Terminating         0          10m
nginx-web-1   0/1     Terminating         0          10m
nginx-web-1   0/1     Pending             0          0s
nginx-web-1   0/1     Pending             0          0s
nginx-web-1   0/1     ContainerCreating   0          0s
nginx-web-1   0/1     Running             0          1s
nginx-web-1   1/1     Running             0          8s
nginx-web-0   1/1     Terminating         0          9m47s
nginx-web-0   0/1     Terminating         0          9m48s
nginx-web-0   0/1     Terminating         0          10m
nginx-web-0   0/1     Terminating         0          10m
nginx-web-0   0/1     Pending             0          0s
nginx-web-0   0/1     Pending             0          0s
nginx-web-0   0/1     ContainerCreating   0          0s
nginx-web-0   0/1     Running             0          1s
nginx-web-0   1/1     Running             0          9s