容器编排系统k8s之ReplicaSet和Deployment控制器

  前文我们了解了k8s上的Pod资源的生命周期、健康状态和就绪状态探测以及资源限制相关话题,回顾请参考https://www.cnblogs.com/qiuhom-1874/p/14143610.html;今天我们来了解下Pod控制器相关话题;

  在k8s上控制器就是k8s的“大脑”,在聊k8s开篇时,我们说过控制器主要负责创建,管理k8s上的资源,如果对应资源不吻合用户定义的资源状态,它就会尝试重启或重建的方式让其状态和用户定义的状态吻合;在k8s上控制器的类型有很多,比如pod控制,service控制器,endpoint控制器等等;不同类型的控制器有着不同的功能和作用;比如pod控制器就是针对pod资源进行管理的控制器;单说pod控制器,它也有很多类型,根据pod里容器跑的应用程序来分类,可以分为有状态应用和无状态应用控制,从应用程序是否运行为守护进程我们可以将控制器分为,守护进程和非守护进程控制器;其中无状态控制器中最常用的有ReplicaSet控制器和Deployment控制;有状态应用控制器常用的有StatefulSet;守护进程控制器最常用的有daemonSet控制器;非守护进程控制器有job控制器,对Job类型的控制器,如果要周期性执行的有Cronjob控制器;

  1、ReplicaSet控制器

  ReplicaSet控制器的主要作用是确保Pod对象副本数量在任何时刻都能精准满足用户期望的数量;这种控制器启动以后,它首先会查找集群中匹配其标签选择器的Pod资源对象,当活动pod数量与用户期望的pod数量不吻合时,如果多了就删除,少了就创建;它创建新pod是靠我们在配置清单中定义的pod模板来创建新pod;

  示例:定义创建ReplicaSet控制器

[root@master01 ~]# cat ReplicaSet-controller-demo.yaml
apiVersion: apps/v1
kind: ReplicaSet
metadata: 
  name: replicaset-demo
  namespace: default
spec:
  replicas: 3
  selector: 
    matchLabels:
      app: nginx-pod
  template:
    metadata:
      labels:
        app: nginx-pod
    spec:
      containers:
      - name: nginx
        image: nginx:1.14-alpine
        ports:
        - name: http
          containerPort: 80
[root@master01 ~]# 

  提示:定义ReplicaSet控制器,apiVersion字段的值为apps/v1,kind为ReplicaSet,这两个字段都是固定的;后面的metadata中主要定义名称和名称空间;spec中主要定义replicas、selector、template;其中replicas这个字段的值为一个整数,表示对应pod的副本数量;selector用于定义标签选择器;其值为一个对象,其中matchLabels字段表示精确匹配标签,这个字段的值为一个字典;除了精确匹配标签选择器这种方式,还有matchExpressions表示使用匹配表达式,其值为一个对象;简单说定义标签选择器,第一种是matchLabels,这种方式就是指定一个或多个标签,每个标签就是一个kvj键值对;后者matchExpressions是指定一个表达式,其值为一个对象,这个对象中主要定义key字段,这个字段定义key的名称;operator定义操作符,values定义值;key和operator字段的值类型都是字符串,其中operator的值有In, NotIn, Exists和DoesNotExist;values是一个字符串列表;其次就是定义pod模板,使用template字段定义,该字段的值为一个对象其中metadata字段用于定义模板的元素据信息,这个元数据信息必须定义标签属性;通常这个标签属性和选择器中的标签相同;spec字段用于定义pod模板的状态,最重要的是定义pod里容器的名字,镜像等等;

  应用资源配置清单

[root@master01 ~]# kubectl apply -f ReplicaSet-controller-demo.yaml
replicaset.apps/replicaset-demo created
[root@master01 ~]# kubectl get rs
NAME              DESIRED   CURRENT   READY   AGE
replicaset-demo   3         3         3       9s
[root@master01 ~]# kubectl get rs -o wide
NAME              DESIRED   CURRENT   READY   AGE   CONTAINERS   IMAGES              SELECTOR
replicaset-demo   3         3         3       17s   nginx        nginx:1.14-alpine   app=nginx-pod
[root@master01 ~]# 

  提示:rs就是ReplicaSet的简写;从上面的信息可以看到对应控制器已经创建;并且当前pod副本数量为3,用户期望的数量也为3,有3个准备就绪;

  查看pod

[root@master01 ~]# kubectl get pod -L app
NAME                    READY   STATUS    RESTARTS   AGE     APP
replicaset-demo-rsl7q   1/1     Running   0          2m57s   nginx-pod
replicaset-demo-twknl   1/1     Running   0          2m57s   nginx-pod
replicaset-demo-vzdbb   1/1     Running   0          2m57s   nginx-pod
[root@master01 ~]# 

  提示:可以看到当前default名称空间中创建了3个pod,其标签为nginx-pod;

  测试:更改其中一个pod的标签为ngx,看看对应控制器是否会新建一个标签为nginx-pod的pod呢?

[root@master01 ~]# kubectl get pod -L app                         
NAME                    READY   STATUS    RESTARTS   AGE     APP
replicaset-demo-rsl7q   1/1     Running   0          5m48s   nginx-pod
replicaset-demo-twknl   1/1     Running   0          5m48s   nginx-pod
replicaset-demo-vzdbb   1/1     Running   0          5m48s   nginx-pod
[root@master01 ~]# kubectl label pod/replicaset-demo-vzdbb app=ngx --overwrite
pod/replicaset-demo-vzdbb labeled
[root@master01 ~]# kubectl get pod -L app
NAME                    READY   STATUS    RESTARTS   AGE    APP
replicaset-demo-qv8tp   1/1     Running   0          4s     nginx-pod
replicaset-demo-rsl7q   1/1     Running   0          6m2s   nginx-pod
replicaset-demo-twknl   1/1     Running   0          6m2s   nginx-pod
replicaset-demo-vzdbb   1/1     Running   0          6m2s   ngx
[root@master01 ~]# 

  提示:可以看到当我们把其中一个pod的标签更改为app=ngx后,对应控制器又会根据pod模板创建一个新pod;

  测试:更改pod标签为app=nginx-pod,看看对应控制器是否会删除一个pod呢?

[root@master01 ~]# kubectl get pod -L app
NAME                    READY   STATUS    RESTARTS   AGE     APP
replicaset-demo-qv8tp   1/1     Running   0          2m35s   nginx-pod
replicaset-demo-rsl7q   1/1     Running   0          8m33s   nginx-pod
replicaset-demo-twknl   1/1     Running   0          8m33s   nginx-pod
replicaset-demo-vzdbb   1/1     Running   0          8m33s   ngx
[root@master01 ~]# kubectl label pod/replicaset-demo-vzdbb app=nginx-pod --overwrite
pod/replicaset-demo-vzdbb labeled
[root@master01 ~]# kubectl get pod -L app
NAME                    READY   STATUS        RESTARTS   AGE     APP
replicaset-demo-qv8tp   0/1     Terminating   0          2m50s   nginx-pod
replicaset-demo-rsl7q   1/1     Running       0          8m48s   nginx-pod
replicaset-demo-twknl   1/1     Running       0          8m48s   nginx-pod
replicaset-demo-vzdbb   1/1     Running       0          8m48s   nginx-pod
[root@master01 ~]# kubectl get pod -L app
NAME                    READY   STATUS    RESTARTS   AGE     APP
replicaset-demo-rsl7q   1/1     Running   0          8m57s   nginx-pod
replicaset-demo-twknl   1/1     Running   0          8m57s   nginx-pod
replicaset-demo-vzdbb   1/1     Running   0          8m57s   nginx-pod
[root@master01 ~]# 

  提示:可以看到当集群中有多余用户期望数量的pod标签时,对应控制器会把多余的相同标签的pod删除;从上面的测试可以看到ReplicaSet控制器是依靠标签选择器来判断集群中pod的数量是否和用户定义的数量吻合,如果不吻合就尝试删除或新建,让对应pod数量精确满足用户期望pod数量;

   查看rs控制器的详细信息

[root@master01 ~]# kubectl describe rs replicaset-demo
Name:         replicaset-demo
Namespace:    default
Selector:     app=nginx-pod
Labels:       <none>
Annotations:  <none>
Replicas:     3 current / 3 desired
Pods Status:  3 Running / 0 Waiting / 0 Succeeded / 0 Failed
Pod Template:
  Labels:  app=nginx-pod
  Containers:
   nginx:
    Image:        nginx:1.14-alpine
    Port:         80/TCP
    Host Port:    0/TCP
    Environment:  <none>
    Mounts:       <none>
  Volumes:        <none>
Events:
  Type    Reason            Age   From                   Message
  ----    ------            ----  ----                   -------
  Normal  SuccessfulCreate  20m   replicaset-controller  Created pod: replicaset-demo-twknl
  Normal  SuccessfulCreate  20m   replicaset-controller  Created pod: replicaset-demo-vzdbb
  Normal  SuccessfulCreate  20m   replicaset-controller  Created pod: replicaset-demo-rsl7q
  Normal  SuccessfulCreate  15m   replicaset-controller  Created pod: replicaset-demo-qv8tp
  Normal  SuccessfulDelete  12m   replicaset-controller  Deleted pod: replicaset-demo-qv8tp
[root@master01 ~]# 

  扩展/缩减rs控制pod副本数量

[root@master01 ~]# kubectl scale rs replicaset-demo --replicas=6
replicaset.apps/replicaset-demo scaled
[root@master01 ~]# kubectl get rs
NAME              DESIRED   CURRENT   READY   AGE
replicaset-demo   6         6         6       32m
[root@master01 ~]# kubectl scale rs replicaset-demo --replicas=4
replicaset.apps/replicaset-demo scaled
[root@master01 ~]# kubectl get rs
NAME              DESIRED   CURRENT   READY   AGE
replicaset-demo   4         4         4       32m
[root@master01 ~]# kubectl get pod
NAME                    READY   STATUS        RESTARTS   AGE
replicaset-demo-5t9tt   0/1     Terminating   0          33s
replicaset-demo-j75hk   1/1     Running       0          33s
replicaset-demo-rsl7q   1/1     Running       0          33m
replicaset-demo-twknl   1/1     Running       0          33m
replicaset-demo-vvqfw   0/1     Terminating   0          33s
replicaset-demo-vzdbb   1/1     Running       0          33m
[root@master01 ~]# kubectl get pod
NAME                    READY   STATUS    RESTARTS   AGE
replicaset-demo-j75hk   1/1     Running   0          41s
replicaset-demo-rsl7q   1/1     Running   0          33m
replicaset-demo-twknl   1/1     Running   0          33m
replicaset-demo-vzdbb   1/1     Running   0          33m
[root@master01 ~]# 

  提示:scale也可以对控制器做扩展和缩减pod副本数量,除了以上使用命令的方式来变更对应pod副本数量;也可以直接在配置清单中修改replicas字段,然后使用apply命令执行配置清单进行修改;

  修改配置清单中的replicas字段的值来扩展pod副本数量

[root@master01 ~]# cat ReplicaSet-controller-demo.yaml
apiVersion: apps/v1
kind: ReplicaSet
metadata: 
  name: replicaset-demo
  namespace: default
spec:
  replicas: 7
  selector: 
    matchLabels:
      app: nginx-pod
  template:
    metadata:
      labels:
        app: nginx-pod
    spec:
      containers:
      - name: nginx
        image: nginx:1.14-alpine
        ports:
        - name: http
          containerPort: 80
[root@master01 ~]# kubectl apply -f ReplicaSet-controller-demo.yaml
replicaset.apps/replicaset-demo configured
[root@master01 ~]# kubectl get rs
NAME              DESIRED   CURRENT   READY   AGE
replicaset-demo   7         7         7       35m
[root@master01 ~]# kubectl get pod
NAME                    READY   STATUS    RESTARTS   AGE
replicaset-demo-j75hk   1/1     Running   0          3m33s
replicaset-demo-k2n9g   1/1     Running   0          9s
replicaset-demo-n7fmk   1/1     Running   0          9s
replicaset-demo-q4dc6   1/1     Running   0          9s
replicaset-demo-rsl7q   1/1     Running   0          36m
replicaset-demo-twknl   1/1     Running   0          36m
replicaset-demo-vzdbb   1/1     Running   0          36m
[root@master01 ~]# 

  更新pod版本

  方式1修改资源配置清单中pod模板的版本,然后在使用apply命令来执行配置清单

[root@master01 ~]# cat ReplicaSet-controller-demo.yaml
apiVersion: apps/v1
kind: ReplicaSet
metadata: 
  name: replicaset-demo
  namespace: default
spec:
  replicas: 7
  selector: 
    matchLabels:
      app: nginx-pod
  template:
    metadata:
      labels:
        app: nginx-pod
    spec:
      containers:
      - name: nginx
        image: nginx:1.16-alpine
        ports:
        - name: http
          containerPort: 80
[root@master01 ~]# kubectl apply -f ReplicaSet-controller-demo.yaml
replicaset.apps/replicaset-demo configured
[root@master01 ~]# kubectl get rs -o wide
NAME              DESIRED   CURRENT   READY   AGE   CONTAINERS   IMAGES              SELECTOR
replicaset-demo   7         7         7       55m   nginx        nginx:1.16-alpine   app=nginx-pod
[root@master01 ~]# 

  提示:从上面命令可以看到,它显示的镜像版本是1.16的版本;

  验证:查看对应pod,看看对应pod中容器镜像版本是否变成了1.16呢?

[root@master01 ~]# kubectl get pod
NAME                    READY   STATUS    RESTARTS   AGE
replicaset-demo-j75hk   1/1     Running   0          25m
replicaset-demo-k2n9g   1/1     Running   0          21m
replicaset-demo-n7fmk   1/1     Running   0          21m
replicaset-demo-q4dc6   1/1     Running   0          21m
replicaset-demo-rsl7q   1/1     Running   0          57m
replicaset-demo-twknl   1/1     Running   0          57m
replicaset-demo-vzdbb   1/1     Running   0          57m
[root@master01 ~]# 

  提示:从pod创建的时间来看,pod没有更新;

  测试:删除一个pod看看对应pod里容器镜像是否会更新呢?

[root@master01 ~]# kubectl get pod
NAME                    READY   STATUS    RESTARTS   AGE
replicaset-demo-j75hk   1/1     Running   0          25m
replicaset-demo-k2n9g   1/1     Running   0          21m
replicaset-demo-n7fmk   1/1     Running   0          21m
replicaset-demo-q4dc6   1/1     Running   0          21m
replicaset-demo-rsl7q   1/1     Running   0          57m
replicaset-demo-twknl   1/1     Running   0          57m
replicaset-demo-vzdbb   1/1     Running   0          57m
[root@master01 ~]# kubectl delete pod/replicaset-demo-vzdbb 
pod "replicaset-demo-vzdbb" deleted
[root@master01 ~]# kubectl get pod
NAME                    READY   STATUS              RESTARTS   AGE
replicaset-demo-9wqj9   0/1     ContainerCreating   0          10s
replicaset-demo-j75hk   1/1     Running             0          26m
replicaset-demo-k2n9g   1/1     Running             0          23m
replicaset-demo-n7fmk   1/1     Running             0          23m
replicaset-demo-q4dc6   1/1     Running             0          23m
replicaset-demo-rsl7q   1/1     Running             0          58m
replicaset-demo-twknl   1/1     Running             0          58m
[root@master01 ~]# kubectl describe pod/replicaset-demo-9wqj9 |grep Image
    Image:          nginx:1.16-alpine
    Image ID:       docker-pullable://nginx@sha256:5057451e461dda671da5e951019ddbff9d96a751fc7d548053523ca1f848c1ad
[root@master01 ~]# 

  提示:可以看到我们删除了一个pod,对应控制器又新建了一个pod,对应新建的pod镜像版本就成为了新版本的pod;从上面测试情况可以看到,对于rs控制器当pod模板中的镜像版本发生更改,如果k8s集群上对应pod数量和用户定义的数量吻合,此时rs控制器不会更新pod;只有新建后的pod才会拥有新版本;也就说如果我们要rs来对pod版本更新,就得删除原有老的pod后才会更新;

  方式2使用命令更新pod版本

[root@master01 ~]# kubectl set image rs replicaset-demo  nginx=nginx:1.18-alpine
replicaset.apps/replicaset-demo image updated
[root@master01 ~]# kubectl get rs -o wide
NAME              DESIRED   CURRENT   READY   AGE   CONTAINERS   IMAGES              SELECTOR
replicaset-demo   7         7         7       72m   nginx        nginx:1.18-alpine   app=nginx-pod
[root@master01 ~]# kubectl get pod
NAME                    READY   STATUS    RESTARTS   AGE
replicaset-demo-9wqj9   1/1     Running   0          13m
replicaset-demo-j75hk   1/1     Running   0          40m
replicaset-demo-k2n9g   1/1     Running   0          36m
replicaset-demo-n7fmk   1/1     Running   0          36m
replicaset-demo-q4dc6   1/1     Running   0          36m
replicaset-demo-rsl7q   1/1     Running   0          72m
replicaset-demo-twknl   1/1     Running   0          72m
[root@master01 ~]# 

  提示:对于rs控制器,不管用命令还是修改资源配置清单中pod模板中镜像版本,如果有和用户期望数量的pod,它是不会自动更新pod版本的;只有手动删除老版本pod,对应新版本pod才会被创建;

  2、deployment控制器

  对于deployment控制来说,它的定义方式和rs控制都差不多,但deploy控制器的功能要比rs强大,它可以实现滚动更新,用户手动定义更新策略;其实deploy控制器是在rs控制器的基础上来管理pod;也就说我们在创建deploy控制器时,它自动会创建一个rs控制器;其中使用deployment控制器创建的pod名称是由deploy控制器名称加上“-”pod模板hash名称加上“-”随机字符串;而对应rs控制器的名称恰好就是deploy控制器名称加“-”pod模板hash;即pod名称就为rs控制器名称加“-”随机字符串;

  示例:创建deployment控制器

[root@master01 ~]# cat deploy-demo.yaml
apiVersion: apps/v1
kind: Deployment
metadata: 
  name: deploy-demo
  namespace: default
spec:
  replicas: 3
  selector: 
    matchLabels:
      app: ngx-dep-pod
  template:
    metadata:
      labels:
        app: ngx-dep-pod
    spec:
      containers:
      - name: nginx
        image: nginx:1.14-alpine
        ports:
        - name: http
          containerPort: 80
[root@master01 ~]# 

  应用配置清单

[root@master01 ~]# kubectl apply -f deploy-demo.yaml
deployment.apps/deploy-demo created
[root@master01 ~]# kubectl get deploy -o wide
NAME          READY   UP-TO-DATE   AVAILABLE   AGE   CONTAINERS   IMAGES              SELECTOR
deploy-demo   3/3     3            3           10s   nginx        nginx:1.14-alpine   app=ngx-dep-pod
[root@master01 ~]# 

  验证:查看是否有rs控制器创建?

[root@master01 ~]# kubectl get rs
NAME                     DESIRED   CURRENT   READY   AGE
deploy-demo-6d795f958b   3         3         3       57s
replicaset-demo          7         7         7       84m
[root@master01 ~]# 

  提示:可以看到有一个deploy-demo-6d795f958b的rs控制器被创建;

  验证:查看pod,看看对应pod名称是否有rs控制器名称加“-”一串随机字符串?

[root@master01 ~]# kubectl  get pod
NAME                           READY   STATUS    RESTARTS   AGE
deploy-demo-6d795f958b-bppjr   1/1     Running   0          2m16s
deploy-demo-6d795f958b-mxwkn   1/1     Running   0          2m16s
deploy-demo-6d795f958b-sh76g   1/1     Running   0          2m16s
replicaset-demo-9wqj9          1/1     Running   0          26m
replicaset-demo-j75hk          1/1     Running   0          52m
replicaset-demo-k2n9g          1/1     Running   0          49m
replicaset-demo-n7fmk          1/1     Running   0          49m
replicaset-demo-q4dc6          1/1     Running   0          49m
replicaset-demo-rsl7q          1/1     Running   0          85m
replicaset-demo-twknl          1/1     Running   0          85m
[root@master01 ~]# 

  提示:可以看到有3个pod的名称是deploy-demo-6d795f958b-加随机字符串;

  更新pod版本

[root@master01 ~]# cat deploy-demo.yaml
apiVersion: apps/v1
kind: Deployment
metadata: 
  name: deploy-demo
  namespace: default
spec:
  replicas: 3
  selector: 
    matchLabels:
      app: ngx-dep-pod
  template:
    metadata:
      labels:
        app: ngx-dep-pod
    spec:
      containers:
      - name: nginx
        image: nginx:1.16-alpine
        ports:
        - name: http
          containerPort: 80
[root@master01 ~]# kubectl apply -f deploy-demo.yaml
deployment.apps/deploy-demo configured
[root@master01 ~]# kubectl get deploy -o wide
NAME          READY   UP-TO-DATE   AVAILABLE   AGE     CONTAINERS   IMAGES              SELECTOR
deploy-demo   3/3     3            3           5m45s   nginx        nginx:1.16-alpine   app=ngx-dep-pod
[root@master01 ~]# kubectl get pod
NAME                          READY   STATUS    RESTARTS   AGE
deploy-demo-95cc58f4d-45l5c   1/1     Running   0          43s
deploy-demo-95cc58f4d-6bmb6   1/1     Running   0          45s
deploy-demo-95cc58f4d-7d5r5   1/1     Running   0          29s
replicaset-demo-9wqj9         1/1     Running   0          30m
replicaset-demo-j75hk         1/1     Running   0          56m
replicaset-demo-k2n9g         1/1     Running   0          53m
replicaset-demo-n7fmk         1/1     Running   0          53m
replicaset-demo-q4dc6         1/1     Running   0          53m
replicaset-demo-rsl7q         1/1     Running   0          89m
replicaset-demo-twknl         1/1     Running   0          89m
[root@master01 ~]# 

  提示:可以看到deploy控制器只要更改了pod模板中镜像版本,对应pod会自动更新;

  使用命令更新pod版本

[root@master01 ~]# kubectl set image deploy deploy-demo nginx=nginx:1.18-alpine
deployment.apps/deploy-demo image updated
[root@master01 ~]# kubectl get deploy
NAME          READY   UP-TO-DATE   AVAILABLE   AGE
deploy-demo   3/3     1            3           9m5s
[root@master01 ~]# kubectl get deploy -o wide
NAME          READY   UP-TO-DATE   AVAILABLE   AGE     CONTAINERS   IMAGES              SELECTOR
deploy-demo   3/3     1            3           9m11s   nginx        nginx:1.18-alpine   app=ngx-dep-pod
[root@master01 ~]# kubectl get deploy -o wide
NAME          READY   UP-TO-DATE   AVAILABLE   AGE     CONTAINERS   IMAGES              SELECTOR
deploy-demo   3/3     3            3           9m38s   nginx        nginx:1.18-alpine   app=ngx-dep-pod
[root@master01 ~]# kubectl get pod
NAME                          READY   STATUS    RESTARTS   AGE
deploy-demo-567b54cd6-6h97c   1/1     Running   0          28s
deploy-demo-567b54cd6-j74t4   1/1     Running   0          27s
deploy-demo-567b54cd6-wcccx   1/1     Running   0          49s
replicaset-demo-9wqj9         1/1     Running   0          34m
replicaset-demo-j75hk         1/1     Running   0          60m
replicaset-demo-k2n9g         1/1     Running   0          56m
replicaset-demo-n7fmk         1/1     Running   0          56m
replicaset-demo-q4dc6         1/1     Running   0          56m
replicaset-demo-rsl7q         1/1     Running   0          92m
replicaset-demo-twknl         1/1     Running   0          92m
[root@master01 ~]# 

  提示:可以看到deploy控制器,只要修改了pod模板中镜像的版本,对应pod就会随之滚动更新到我们指定的版本;

  查看rs历史版本

[root@master01 ~]# kubectl get rs -o wide
NAME                     DESIRED   CURRENT   READY   AGE     CONTAINERS   IMAGES              SELECTOR
deploy-demo-567b54cd6    3         3         3       3m50s   nginx        nginx:1.18-alpine   app=ngx-dep-pod,pod-template-hash=567b54cd6
deploy-demo-6d795f958b   0         0         0       12m     nginx        nginx:1.14-alpine   app=ngx-dep-pod,pod-template-hash=6d795f958b
deploy-demo-95cc58f4d    0         0         0       7m27s   nginx        nginx:1.16-alpine   app=ngx-dep-pod,pod-template-hash=95cc58f4d
replicaset-demo          7         7         7       95m     nginx        nginx:1.18-alpine   app=nginx-pod
[root@master01 ~]# 

  提示:deploy控制器的更新pod版本操作,它会记录rs的所有历史版本;因为只要pod模板的hash值发生变化,对应的rs就会重新被创建一遍,不同于rs控制器,历史版本的rs上没有pod运行,只有当前版本的rs上才会运行pod;

  查看更新历史记录

[root@master01 ~]# kubectl rollout history deploy/deploy-demo
deployment.apps/deploy-demo 
REVISION  CHANGE-CAUSE
1         <none>
2         <none>
3         <none>

[root@master01 ~]# 

  提示:这里可以看到有3个版本,没有记录对应的原因;这是因为我们在更新pod版本是没有记录;要想记录器更新原因,可以在对应名后面加--record选项即可;

  示例:记录更新操作命令到更新历史记录

[root@master01 ~]# kubectl set image deploy deploy-demo nginx=nginx:1.14-alpine --record 
deployment.apps/deploy-demo image updated
[root@master01 ~]# kubectl rollout history deploy/deploy-demo
deployment.apps/deploy-demo 
REVISION  CHANGE-CAUSE
2         <none>
3         <none>
4         kubectl set image deploy deploy-demo nginx=nginx:1.14-alpine --record=true

[root@master01 ~]# kubectl apply -f deploy-demo-nginx-1.16.yaml --record
deployment.apps/deploy-demo configured
[root@master01 ~]# kubectl rollout history deploy/deploy-demo
deployment.apps/deploy-demo 
REVISION  CHANGE-CAUSE
3         <none>
4         kubectl set image deploy deploy-demo nginx=nginx:1.14-alpine --record=true
5         kubectl apply --filename=deploy-demo-nginx-1.16.yaml --record=true

[root@master01 ~]# 

  提示:可以看到更新操作时加上--record选项后,再次查看更新历史记录,就能显示对应的更新命令;

  回滚到上一个版本

[root@master01 ~]# kubectl get deploy -o wide
NAME          READY   UP-TO-DATE   AVAILABLE   AGE   CONTAINERS   IMAGES              SELECTOR
deploy-demo   3/3     3            3           33m   nginx        nginx:1.16-alpine   app=ngx-dep-pod
[root@master01 ~]# kubectl get rs -o wide    
NAME                     DESIRED   CURRENT   READY   AGE    CONTAINERS   IMAGES              SELECTOR
deploy-demo-567b54cd6    0         0         0       24m    nginx        nginx:1.18-alpine   app=ngx-dep-pod,pod-template-hash=567b54cd6
deploy-demo-6d795f958b   0         0         0       33m    nginx        nginx:1.14-alpine   app=ngx-dep-pod,pod-template-hash=6d795f958b
deploy-demo-95cc58f4d    3         3         3       28m    nginx        nginx:1.16-alpine   app=ngx-dep-pod,pod-template-hash=95cc58f4d
replicaset-demo          7         7         7       116m   nginx        nginx:1.18-alpine   app=nginx-pod
[root@master01 ~]# kubectl rollout history deploy/deploy-demo
deployment.apps/deploy-demo 
REVISION  CHANGE-CAUSE
3         <none>
4         kubectl set image deploy deploy-demo nginx=nginx:1.14-alpine --record=true
5         kubectl apply --filename=deploy-demo-nginx-1.16.yaml --record=true

[root@master01 ~]# kubectl rollout undo deploy/deploy-demo
deployment.apps/deploy-demo rolled back
[root@master01 ~]# kubectl rollout history deploy/deploy-demo
deployment.apps/deploy-demo 
REVISION  CHANGE-CAUSE
3         <none>
5         kubectl apply --filename=deploy-demo-nginx-1.16.yaml --record=true
6         kubectl set image deploy deploy-demo nginx=nginx:1.14-alpine --record=true

[root@master01 ~]# kubectl get deploy -o wide
NAME          READY   UP-TO-DATE   AVAILABLE   AGE   CONTAINERS   IMAGES              SELECTOR
deploy-demo   3/3     3            3           34m   nginx        nginx:1.14-alpine   app=ngx-dep-pod
[root@master01 ~]# kubectl get rs -o wide
NAME                     DESIRED   CURRENT   READY   AGE    CONTAINERS   IMAGES              SELECTOR
deploy-demo-567b54cd6    0         0         0       26m    nginx        nginx:1.18-alpine   app=ngx-dep-pod,pod-template-hash=567b54cd6
deploy-demo-6d795f958b   3         3         3       35m    nginx        nginx:1.14-alpine   app=ngx-dep-pod,pod-template-hash=6d795f958b
deploy-demo-95cc58f4d    0         0         0       29m    nginx        nginx:1.16-alpine   app=ngx-dep-pod,pod-template-hash=95cc58f4d
replicaset-demo          7         7         7       118m   nginx        nginx:1.18-alpine   app=nginx-pod
[root@master01 ~]# 

  提示:可以看到执行了kubectl rollout undo deploy/deploy-demo命令后,对应版本从1.16就回滚到1.14的版本了;对应更新历史记录也把1.14版本更新为当前最新记录;

  回滚到指定历史记录版本

[root@master01 ~]# kubectl rollout history deploy/deploy-demo
deployment.apps/deploy-demo 
REVISION  CHANGE-CAUSE
3         <none>
5         kubectl apply --filename=deploy-demo-nginx-1.16.yaml --record=true
6         kubectl set image deploy deploy-demo nginx=nginx:1.14-alpine --record=true

[root@master01 ~]# kubectl rollout undo deploy/deploy-demo --to-revision=3
deployment.apps/deploy-demo rolled back
[root@master01 ~]# kubectl rollout history deploy/deploy-demo             
deployment.apps/deploy-demo 
REVISION  CHANGE-CAUSE
5         kubectl apply --filename=deploy-demo-nginx-1.16.yaml --record=true
6         kubectl set image deploy deploy-demo nginx=nginx:1.14-alpine --record=true
7         <none>

[root@master01 ~]# kubectl get deploy -o wide
NAME          READY   UP-TO-DATE   AVAILABLE   AGE   CONTAINERS   IMAGES              SELECTOR
deploy-demo   3/3     3            3           42m   nginx        nginx:1.18-alpine   app=ngx-dep-pod
[root@master01 ~]# kubectl get rs -o wide
NAME                     DESIRED   CURRENT   READY   AGE    CONTAINERS   IMAGES              SELECTOR
deploy-demo-567b54cd6    3         3         3       33m    nginx        nginx:1.18-alpine   app=ngx-dep-pod,pod-template-hash=567b54cd6
deploy-demo-6d795f958b   0         0         0       42m    nginx        nginx:1.14-alpine   app=ngx-dep-pod,pod-template-hash=6d795f958b
deploy-demo-95cc58f4d    0         0         0       36m    nginx        nginx:1.16-alpine   app=ngx-dep-pod,pod-template-hash=95cc58f4d
replicaset-demo          7         7         7       125m   nginx        nginx:1.18-alpine   app=nginx-pod
[root@master01 ~]# 

  提示:指定要回滚到某个历史记录的版本,可以使用--to-revision选项来指定历史记录的编号;

  查看deploy控制器的详细信息

[root@master01 ~]# kubectl describe deploy deploy-demo
Name:                   deploy-demo
Namespace:              default
CreationTimestamp:      Thu, 17 Dec 2020 23:40:11 +0800
Labels:                 <none>
Annotations:            deployment.kubernetes.io/revision: 7
Selector:               app=ngx-dep-pod
Replicas:               3 desired | 3 updated | 3 total | 3 available | 0 unavailable
StrategyType:           RollingUpdate
MinReadySeconds:        0
RollingUpdateStrategy:  25% max unavailable, 25% max surge
Pod Template:
  Labels:  app=ngx-dep-pod
  Containers:
   nginx:
    Image:        nginx:1.18-alpine
    Port:         80/TCP
    Host Port:    0/TCP
    Environment:  <none>
    Mounts:       <none>
  Volumes:        <none>
Conditions:
  Type           Status  Reason
  ----           ------  ------
  Available      True    MinimumReplicasAvailable
  Progressing    True    NewReplicaSetAvailable
OldReplicaSets:  <none>
NewReplicaSet:   deploy-demo-567b54cd6 (3/3 replicas created)
Events:
  Type    Reason             Age                 From                   Message
  ----    ------             ----                ----                   -------
  Normal  ScalingReplicaSet  58m                 deployment-controller  Scaled down replica set deploy-demo-6d795f958b to 1
  Normal  ScalingReplicaSet  58m                 deployment-controller  Scaled up replica set deploy-demo-95cc58f4d to 3
  Normal  ScalingReplicaSet  58m                 deployment-controller  Scaled down replica set deploy-demo-6d795f958b to 0
  Normal  ScalingReplicaSet  55m                 deployment-controller  Scaled up replica set deploy-demo-567b54cd6 to 1
  Normal  ScalingReplicaSet  54m                 deployment-controller  Scaled down replica set deploy-demo-95cc58f4d to 2
  Normal  ScalingReplicaSet  38m                 deployment-controller  Scaled up replica set deploy-demo-6d795f958b to 1
  Normal  ScalingReplicaSet  38m                 deployment-controller  Scaled down replica set deploy-demo-567b54cd6 to 2
  Normal  ScalingReplicaSet  38m                 deployment-controller  Scaled up replica set deploy-demo-6d795f958b to 2
  Normal  ScalingReplicaSet  37m                 deployment-controller  Scaled down replica set deploy-demo-567b54cd6 to 1
  Normal  ScalingReplicaSet  37m                 deployment-controller  Scaled down replica set deploy-demo-567b54cd6 to 0
  Normal  ScalingReplicaSet  33m (x2 over 58m)   deployment-controller  Scaled up replica set deploy-demo-95cc58f4d to 1
  Normal  ScalingReplicaSet  33m (x2 over 58m)   deployment-controller  Scaled up replica set deploy-demo-95cc58f4d to 2
  Normal  ScalingReplicaSet  33m (x2 over 58m)   deployment-controller  Scaled down replica set deploy-demo-6d795f958b to 2
  Normal  ScalingReplicaSet  29m (x3 over 64m)   deployment-controller  Scaled up replica set deploy-demo-6d795f958b to 3
  Normal  ScalingReplicaSet  22m (x14 over 54m)  deployment-controller  (combined from similar events): Scaled down replica set deploy-demo-6d795f958b to 2
[root@master01 ~]# 

  提示:查看deploy控制器的详细信息,可以看到对应pod模板,回滚的过程,以及默认更新策略等等信息;

  自定义滚动更新策略

[root@master01 ~]# cat deploy-demo-nginx-1.14.yaml
apiVersion: apps/v1
kind: Deployment
metadata: 
  name: deploy-demo
  namespace: default
spec:
  replicas: 3
  selector: 
    matchLabels:
      app: ngx-dep-pod
  template:
    metadata:
      labels:
        app: ngx-dep-pod
    spec:
      containers:
      - name: nginx
        image: nginx:1.14-alpine
        ports:
        - name: http
          containerPort: 80
  strategy:
    type: RollingUpdate
    rollingUpdate:
      maxSurge: 2
      maxUnavailable: 1
  minReadySeconds: 5
[root@master01 ~]# 

  提示:定义滚动更新策略需要使用strategy这个字段,这个字段的值是一个对象,其中type是指定更新策略,其策略有两种,第一种是Recreate,这种策略更新方式是新建一个新版pod,然后再删除一个旧版pod以这种方式滚动更新;第二种是RollingUpdate,这种策略是用于我们手动指定的策略;其中maxSurge表示最大允许超出用户期望的pod数量(即更新时允许新建超出用户期望的pod数量),maxUnavailable表示最大允许少于用于期望的pod数量(即更新时可以一次删除几个旧版pod);最后minReadySeconds字段不是定义更新策略的,它是spec中的一个字段,用于限定pod最小就绪时长;以上更新策略表示,使用RollingUpdate类型策略,并指定最大新建pod超出用户期望pod数量为2个,最大允许少于用户期望pod数量为1个;pod最小就绪时间为5秒;

  应用配置清单

[root@master01 ~]# kubectl apply -f deploy-demo-nginx-1.14.yaml
deployment.apps/deploy-demo configured
[root@master01 ~]# kubectl describe deploy/deploy-demo
Name:                   deploy-demo
Namespace:              default
CreationTimestamp:      Thu, 17 Dec 2020 23:40:11 +0800
Labels:                 <none>
Annotations:            deployment.kubernetes.io/revision: 8
Selector:               app=ngx-dep-pod
Replicas:               3 desired | 3 updated | 3 total | 3 available | 0 unavailable
StrategyType:           RollingUpdate
MinReadySeconds:        5
RollingUpdateStrategy:  1 max unavailable, 2 max surge
Pod Template:
  Labels:  app=ngx-dep-pod
  Containers:
   nginx:
    Image:        nginx:1.14-alpine
    Port:         80/TCP
    Host Port:    0/TCP
    Environment:  <none>
    Mounts:       <none>
  Volumes:        <none>
Conditions:
  Type           Status  Reason
  ----           ------  ------
  Available      True    MinimumReplicasAvailable
  Progressing    True    NewReplicaSetAvailable
OldReplicaSets:  <none>
NewReplicaSet:   deploy-demo-6d795f958b (3/3 replicas created)
Events:
  Type    Reason             Age                 From                   Message
  ----    ------             ----                ----                   -------
  Normal  ScalingReplicaSet  47m                 deployment-controller  Scaled up replica set deploy-demo-6d795f958b to 1
  Normal  ScalingReplicaSet  47m                 deployment-controller  Scaled down replica set deploy-demo-567b54cd6 to 1
  Normal  ScalingReplicaSet  42m (x2 over 68m)   deployment-controller  Scaled up replica set deploy-demo-95cc58f4d to 1
  Normal  ScalingReplicaSet  42m (x2 over 68m)   deployment-controller  Scaled up replica set deploy-demo-95cc58f4d to 2
  Normal  ScalingReplicaSet  42m (x2 over 68m)   deployment-controller  Scaled down replica set deploy-demo-6d795f958b to 2
  Normal  ScalingReplicaSet  31m (x14 over 64m)  deployment-controller  (combined from similar events): Scaled down replica set deploy-demo-6d795f958b to 2
  Normal  ScalingReplicaSet  41s (x4 over 73m)   deployment-controller  Scaled up replica set deploy-demo-6d795f958b to 3
  Normal  ScalingReplicaSet  41s (x2 over 47m)   deployment-controller  Scaled down replica set deploy-demo-567b54cd6 to 2
  Normal  ScalingReplicaSet  41s (x2 over 47m)   deployment-controller  Scaled up replica set deploy-demo-6d795f958b to 2
  Normal  ScalingReplicaSet  34s (x2 over 47m)   deployment-controller  Scaled down replica set deploy-demo-567b54cd6 to 0
[root@master01 ~]# 

  提示:可以看到对应deploy控制器的更新策略已经更改为我们定义的策略;为了能够看出更新的效果,我们这里先手动把pod数量调整为10个;

  扩展pod副本数量

[root@master01 ~]# kubectl scale deploy/deploy-demo --replicas=10
deployment.apps/deploy-demo scaled
[root@master01 ~]# kubectl get pods
NAME                           READY   STATUS    RESTARTS   AGE
deploy-demo-6d795f958b-5bdfw   1/1     Running   0          3m33s
deploy-demo-6d795f958b-5zr7r   1/1     Running   0          8s
deploy-demo-6d795f958b-9mc7k   1/1     Running   0          8s
deploy-demo-6d795f958b-czwdp   1/1     Running   0          3m33s
deploy-demo-6d795f958b-jfrnc   1/1     Running   0          8s
deploy-demo-6d795f958b-jw9n8   1/1     Running   0          3m33s
deploy-demo-6d795f958b-mbrlw   1/1     Running   0          8s
deploy-demo-6d795f958b-ph99t   1/1     Running   0          8s
deploy-demo-6d795f958b-wzscg   1/1     Running   0          8s
deploy-demo-6d795f958b-z5mnf   1/1     Running   0          8s
replicaset-demo-9wqj9          1/1     Running   0          100m
replicaset-demo-j75hk          1/1     Running   0          126m
replicaset-demo-k2n9g          1/1     Running   0          123m
replicaset-demo-n7fmk          1/1     Running   0          123m
replicaset-demo-q4dc6          1/1     Running   0          123m
replicaset-demo-rsl7q          1/1     Running   0          159m
replicaset-demo-twknl          1/1     Running   0          159m
[root@master01 ~]# 

  查看更新过程

[root@master01 ~]# kubectl get pod -w
NAME                           READY   STATUS    RESTARTS   AGE
deploy-demo-6d795f958b-5bdfw   1/1     Running   0          5m18s
deploy-demo-6d795f958b-5zr7r   1/1     Running   0          113s
deploy-demo-6d795f958b-9mc7k   1/1     Running   0          113s
deploy-demo-6d795f958b-czwdp   1/1     Running   0          5m18s
deploy-demo-6d795f958b-jfrnc   1/1     Running   0          113s
deploy-demo-6d795f958b-jw9n8   1/1     Running   0          5m18s
deploy-demo-6d795f958b-mbrlw   1/1     Running   0          113s
deploy-demo-6d795f958b-ph99t   1/1     Running   0          113s
deploy-demo-6d795f958b-wzscg   1/1     Running   0          113s
deploy-demo-6d795f958b-z5mnf   1/1     Running   0          113s
replicaset-demo-9wqj9          1/1     Running   0          102m
replicaset-demo-j75hk          1/1     Running   0          128m
replicaset-demo-k2n9g          1/1     Running   0          125m
replicaset-demo-n7fmk          1/1     Running   0          125m
replicaset-demo-q4dc6          1/1     Running   0          125m
replicaset-demo-rsl7q          1/1     Running   0          161m
replicaset-demo-twknl          1/1     Running   0          161m
deploy-demo-578d6b6f94-qhc9j   0/1     Pending   0          0s
deploy-demo-578d6b6f94-qhc9j   0/1     Pending   0          0s
deploy-demo-578d6b6f94-95srs   0/1     Pending   0          0s
deploy-demo-6d795f958b-mbrlw   1/1     Terminating   0          4m16s
deploy-demo-578d6b6f94-95srs   0/1     Pending       0          0s
deploy-demo-578d6b6f94-qhc9j   0/1     ContainerCreating   0          0s
deploy-demo-578d6b6f94-95srs   0/1     ContainerCreating   0          0s
deploy-demo-578d6b6f94-bht84   0/1     Pending             0          0s
deploy-demo-578d6b6f94-bht84   0/1     Pending             0          0s
deploy-demo-578d6b6f94-bht84   0/1     ContainerCreating   0          0s
deploy-demo-6d795f958b-mbrlw   0/1     Terminating         0          4m17s
deploy-demo-6d795f958b-mbrlw   0/1     Terminating         0          4m24s
deploy-demo-6d795f958b-mbrlw   0/1     Terminating         0          4m24s
deploy-demo-578d6b6f94-qhc9j   1/1     Running             0          15s
deploy-demo-578d6b6f94-95srs   1/1     Running             0          16s
deploy-demo-578d6b6f94-bht84   1/1     Running             0          18s
deploy-demo-6d795f958b-ph99t   1/1     Terminating         0          4m38s
deploy-demo-6d795f958b-jfrnc   1/1     Terminating         0          4m38s
deploy-demo-578d6b6f94-lg6vk   0/1     Pending             0          0s
deploy-demo-578d6b6f94-g9c8x   0/1     Pending             0          0s
deploy-demo-578d6b6f94-lg6vk   0/1     Pending             0          0s
deploy-demo-578d6b6f94-g9c8x   0/1     Pending             0          0s
deploy-demo-578d6b6f94-lg6vk   0/1     ContainerCreating   0          0s
deploy-demo-578d6b6f94-g9c8x   0/1     ContainerCreating   0          0s
deploy-demo-6d795f958b-ph99t   0/1     Terminating         0          4m38s
deploy-demo-6d795f958b-jfrnc   0/1     Terminating         0          4m38s
deploy-demo-6d795f958b-5zr7r   1/1     Terminating         0          4m43s
deploy-demo-578d6b6f94-4rpx9   0/1     Pending             0          0s
deploy-demo-578d6b6f94-4rpx9   0/1     Pending             0          0s
deploy-demo-578d6b6f94-4rpx9   0/1     ContainerCreating   0          0s
deploy-demo-6d795f958b-5zr7r   0/1     Terminating         0          4m43s
deploy-demo-6d795f958b-ph99t   0/1     Terminating         0          4m44s
deploy-demo-6d795f958b-ph99t   0/1     Terminating         0          4m44s
deploy-demo-6d795f958b-jfrnc   0/1     Terminating         0          4m44s
deploy-demo-6d795f958b-jfrnc   0/1     Terminating         0          4m44s
deploy-demo-578d6b6f94-g9c8x   1/1     Running             0          12s
deploy-demo-6d795f958b-5zr7r   0/1     Terminating         0          4m51s
deploy-demo-6d795f958b-5zr7r   0/1     Terminating         0          4m51s
deploy-demo-578d6b6f94-lg6vk   1/1     Running             0          15s
deploy-demo-6d795f958b-9mc7k   1/1     Terminating         0          4m56s
deploy-demo-578d6b6f94-4lbwg   0/1     Pending             0          0s
deploy-demo-578d6b6f94-4lbwg   0/1     Pending             0          0s
deploy-demo-578d6b6f94-4lbwg   0/1     ContainerCreating   0          0s
deploy-demo-578d6b6f94-4rpx9   1/1     Running             0          13s
deploy-demo-6d795f958b-9mc7k   0/1     Terminating         0          4m57s
deploy-demo-578d6b6f94-4lbwg   1/1     Running             0          2s
deploy-demo-6d795f958b-wzscg   1/1     Terminating         0          4m58s
deploy-demo-578d6b6f94-fhkk9   0/1     Pending             0          0s
deploy-demo-578d6b6f94-fhkk9   0/1     Pending             0          0s
deploy-demo-578d6b6f94-fhkk9   0/1     ContainerCreating   0          0s
deploy-demo-6d795f958b-wzscg   0/1     Terminating         0          4m59s
deploy-demo-578d6b6f94-fhkk9   1/1     Running             0          2s
deploy-demo-6d795f958b-z5mnf   1/1     Terminating         0          5m2s
deploy-demo-578d6b6f94-sfpz4   0/1     Pending             0          1s
deploy-demo-578d6b6f94-sfpz4   0/1     Pending             0          1s
deploy-demo-6d795f958b-czwdp   1/1     Terminating         0          8m28s
deploy-demo-578d6b6f94-sfpz4   0/1     ContainerCreating   0          1s
deploy-demo-578d6b6f94-5bs6z   0/1     Pending             0          0s
deploy-demo-578d6b6f94-5bs6z   0/1     Pending             0          0s
deploy-demo-578d6b6f94-5bs6z   0/1     ContainerCreating   0          0s
deploy-demo-6d795f958b-czwdp   0/1     Terminating         0          8m28s
deploy-demo-6d795f958b-z5mnf   0/1     Terminating         0          5m4s
deploy-demo-578d6b6f94-sfpz4   1/1     Running             0          2s
deploy-demo-6d795f958b-5bdfw   1/1     Terminating         0          8m29s
deploy-demo-6d795f958b-9mc7k   0/1     Terminating         0          5m4s
deploy-demo-6d795f958b-9mc7k   0/1     Terminating         0          5m4s
deploy-demo-578d6b6f94-5bs6z   1/1     Running             0          1s
deploy-demo-6d795f958b-5bdfw   0/1     Terminating         0          8m30s
deploy-demo-6d795f958b-czwdp   0/1     Terminating         0          8m36s
deploy-demo-6d795f958b-czwdp   0/1     Terminating         0          8m36s
deploy-demo-6d795f958b-5bdfw   0/1     Terminating         0          8m36s
deploy-demo-6d795f958b-5bdfw   0/1     Terminating         0          8m36s
deploy-demo-6d795f958b-wzscg   0/1     Terminating         0          5m11s
deploy-demo-6d795f958b-wzscg   0/1     Terminating         0          5m11s
deploy-demo-6d795f958b-jw9n8   1/1     Terminating         0          8m38s
deploy-demo-6d795f958b-jw9n8   0/1     Terminating         0          8m38s
deploy-demo-6d795f958b-z5mnf   0/1     Terminating         0          5m14s
deploy-demo-6d795f958b-z5mnf   0/1     Terminating         0          5m14s
deploy-demo-6d795f958b-jw9n8   0/1     Terminating         0          8m46s
deploy-demo-6d795f958b-jw9n8   0/1     Terminating         0          8m46s

  提示:使用-w选项可以一直跟踪查看pod变化过程;从上面的监控信息可以看到,在更新时,首先是将三个pod标记为pending状态,然后先删除一个pod,然后再创建两个pod;然后又创建一个,再删除3个,一次进行;不管怎么删除和新建,对应新旧pod的数量最少要有9个,最大不超过12个;

  使用暂停更新实现金丝雀发布

[root@master01 ~]# kubectl set image deploy/deploy-demo nginx=nginx:1.14-alpine && kubectl rollout pause deploy/deploy-demo 
deployment.apps/deploy-demo image updated
deployment.apps/deploy-demo paused
[root@master01 ~]# 

  提示:以上命令会根据我们定义的更新策略,先删除一个pod,然后再创建3个新版pod,然后更新操作就暂停了;此时对应pod只更新了1个,然后新建了2个新pod,总共就有12个pod;

  查看pod情况

[root@master01 ~]# kubectl get pod
NAME                           READY   STATUS    RESTARTS   AGE
deploy-demo-6d795f958b-df77k   1/1     Running   0          87s
deploy-demo-6d795f958b-tll8b   1/1     Running   0          87s
deploy-demo-6d795f958b-zbhwp   1/1     Running   0          87s
deploy-demo-fb957b9b-44l6g     1/1     Running   0          3m21s
deploy-demo-fb957b9b-7q6wh     1/1     Running   0          3m38s
deploy-demo-fb957b9b-d45rg     1/1     Running   0          3m27s
deploy-demo-fb957b9b-j7p2j     1/1     Running   0          3m38s
deploy-demo-fb957b9b-mkpz6     1/1     Running   0          3m38s
deploy-demo-fb957b9b-qctnv     1/1     Running   0          3m21s
deploy-demo-fb957b9b-rvrtf     1/1     Running   0          3m27s
deploy-demo-fb957b9b-wf254     1/1     Running   0          3m12s
deploy-demo-fb957b9b-xclhz     1/1     Running   0          3m22s
replicaset-demo-9wqj9          1/1     Running   0          135m
replicaset-demo-j75hk          1/1     Running   0          161m
replicaset-demo-k2n9g          1/1     Running   0          158m
replicaset-demo-n7fmk          1/1     Running   0          158m
replicaset-demo-q4dc6          1/1     Running   0          158m
replicaset-demo-rsl7q          1/1     Running   0          3h14m
replicaset-demo-twknl          1/1     Running   0          3h14m
[root@master01 ~]# kubectl get pod|grep "^deploy.*" |wc -l
12
[root@master01 ~]# 

  提示:之所以多两个是因为我们在更新策略中定义允许最大超出用户期望2个pod;

  恢复更新

[root@master01 ~]# kubectl rollout resume deploy/deploy-demo && kubectl rollout status deploy/deploy-demo
deployment.apps/deploy-demo resumed
Waiting for deployment "deploy-demo" rollout to finish: 3 out of 10 new replicas have been updated...
Waiting for deployment "deploy-demo" rollout to finish: 6 out of 10 new replicas have been updated...
Waiting for deployment "deploy-demo" rollout to finish: 6 out of 10 new replicas have been updated...
Waiting for deployment "deploy-demo" rollout to finish: 6 out of 10 new replicas have been updated...
Waiting for deployment "deploy-demo" rollout to finish: 6 out of 10 new replicas have been updated...
Waiting for deployment "deploy-demo" rollout to finish: 6 out of 10 new replicas have been updated...
Waiting for deployment "deploy-demo" rollout to finish: 6 out of 10 new replicas have been updated...
Waiting for deployment "deploy-demo" rollout to finish: 9 out of 10 new replicas have been updated...
Waiting for deployment "deploy-demo" rollout to finish: 9 out of 10 new replicas have been updated...
Waiting for deployment "deploy-demo" rollout to finish: 9 out of 10 new replicas have been updated...
Waiting for deployment "deploy-demo" rollout to finish: 9 out of 10 new replicas have been updated...
Waiting for deployment "deploy-demo" rollout to finish: 9 out of 10 new replicas have been updated...
Waiting for deployment "deploy-demo" rollout to finish: 9 out of 10 new replicas have been updated...
Waiting for deployment "deploy-demo" rollout to finish: 9 of 10 updated replicas are available...
Waiting for deployment "deploy-demo" rollout to finish: 9 of 10 updated replicas are available...
deployment "deploy-demo" successfully rolled out
[root@master01 ~]# 

  提示:resume表示恢复刚才暂停的更新操作;status是用来查看对应更新过程;

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