K8s资源第二篇（Pod控制器）

Pod控制器：

Pod类型：

• 自主式Pod：由用户自己通过命令create，apply手动创建的Pod，用户可以自己删除。
• 被管控式Pod：使用run命令创建的Pod，由Pod控制器管控，用户删除Pod的话，Pod会被重建。

Pod控制器：

• ReplicationController：后续会被ReplicaSet替代。
• ReplicaSet：用作Pod的创建，删除更新，ReplicaSet能确保运行指定数量的Pod，通过label selector来确定pod数量是否满足用户指定的副本数量。
• Deployment：用来将Pod和ReplicaSet的实际状态改变为用户的期望状态，之处扩容，回滚，更新等功能；管理无状态应用最好的控制器，守护进程类。
• DaemonSet：用来确保每个节点上运行一个Pod副本，无状态服务，守护进程类。
• Job：用来执行一次运行任务，不需要持续运行。
• CronJob：用来周期性运行任务，不需要持续运行。
• StatefulSet：用来管理有状态应用，每一个应用都被单独管理，管理比较麻烦。

ReplicaSet：

 虽然ReplicaSet可以独立使用，但它主要被Deployment用作Pod机制的创建，删除和更新，当使用Deployment时，你不必担心创建Pod的ReplicaSet，因为Deployment可以实现管理ReplicaSet。

ReplicaSet资源清单的主要字段：

apiVersion: apps/v1      #版本
kind: ReplicaSet        #资源类型
metadata:               #元数据
spec:                   #期望状态
  minReadySecons:       #新创建Pod准备好的最小时间，单位秒。
  replicas:             #副本数，默认为1。
  selector:             #标签选择器。
  template:             #模板（必要字段）
    metadata:           #模板中的元数据
    spec:               #模板的期望状态
status:                 #当前实际状态。 

#新建一个ReplicaSet
[root@k8smaster ~]# cd /data/
[root@k8smaster data]# vim rs-demo.yaml
apiVersion: apps/v1
kind: ReplicaSet
metadata:
  name: myrs
  namespace: default
spec:
  replicas: 2
  selector:
    matchLabels:
      app: myrs
      release: canary
  template:
    metadata:
      name: myrs-pod
      labels:
        app: myrs
        release: canary
        environment: qa
    spec:
      containers:
      - name: myapp-container
        image: ikubernetes/myapp:v1
        ports:
        - name: http
          containerPort: 80
[root@k8smaster data]# kubectl apply -f rs-demo.yaml 
replicaset.apps/myrs created
[root@k8smaster data]# kubectl get rs
NAME                          DESIRED   CURRENT   READY   AGE
myapp-deployment-558f94fb55   3         3         3       40d
myrs                          2         2         2       80s
nginx-deployment-6f77f65499   1         1         1       39d
[root@k8smaster data]# kubectl get pods
NAME                                READY   STATUS             RESTARTS   AGE
memleak-pod                         0/1     CrashLoopBackOff   29         126m
myapp-deployment-558f94fb55-plk4v   1/1     Running            3          40d
myapp-deployment-558f94fb55-rd8f5   1/1     Running            3          40d
myapp-deployment-558f94fb55-zzmpg   1/1     Running            3          40d
mypod                               1/1     Running            2          6d2h
myrs-74ntr                          1/1     Running            0          103s
myrs-vmchf                          1/1     Running            0          103s
nginx-deployment-6f77f65499-8g24d   1/1     Running            3          39d
pod-demo                            2/2     Running            4          6d3h
readiness-exec                      1/1     Running            1          4d
[root@k8smaster data]# kubectl describe pod myrs-74ntr
Name:           myrs-74ntr
Namespace:      default
Priority:       0
Node:           k8snode2/192.168.43.176
Start Time:     Tue, 10 Dec 2019 17:44:27 +0800
Labels:         app=myrs
                environment=qa
                release=canary
Annotations:    
Status:         Running
IP:             10.244.2.107
IPs:            
Controlled By:  ReplicaSet/myrs
Containers:
  myapp-container:
    Container ID:   docker://d3c07f789f8167479a2326ba5cb03eec094b09a507f79ca3d5386a6302605d52
    Image:          ikubernetes/myapp:v1
    Image ID:       docker-pullable://ikubernetes/myapp@sha256:40ccda7b7e2d080bee7620b6d3f5e6697894befc409582902a67c963d30a6113
    Port:           80/TCP
    Host Port:      0/TCP
    State:          Running
      Started:      Tue, 10 Dec 2019 17:44:28 +0800
    Ready:          True
    Restart Count:  0
    Environment:    
    Mounts:
      /var/run/secrets/kubernetes.io/serviceaccount from default-token-kk2fq (ro)
Conditions:
  Type              Status
  Initialized       True 
  Ready             True 
  ContainersReady   True 
  PodScheduled      True 
Volumes:
  default-token-kk2fq:
    Type:        Secret (a volume populated by a Secret)
    SecretName:  default-token-kk2fq
    Optional:    false
QoS Class:       BestEffort
Node-Selectors:  
Tolerations:     node.kubernetes.io/not-ready:NoExecute for 300s
                node.kubernetes.io/unreachable:NoExecute for 300s
Events:
  Type    Reason     Age    From               Message
  ----    ------     ----   ----               -------
  Normal  Scheduled  2m32s  default-scheduler  Successfully assigned default/myrs-74ntr to k8snode2
  Normal  Pulled     2m30s  kubelet, k8snode2  Container image "ikubernetes/myapp:v1" already present on machine
  Normal  Created    2m30s  kubelet, k8snode2  Created container myapp-container
  Normal  Started    2m30s  kubelet, k8snode2  Started container myapp-container
[root@k8smaster data]# curl 10.244.2.107
Hello MyApp | Version: v1 | Pod Name

如果删除一个副本：

[root@k8smaster data]# kubectl delete pods myrs-74ntr
pod "myrs-74ntr" deleted
[root@k8smaster data]# kubectl get pods
NAME                                READY   STATUS             RESTARTS   AGE
memleak-pod                         0/1     CrashLoopBackOff   30         131m
myapp-deployment-558f94fb55-plk4v   1/1     Running            3          40d
myapp-deployment-558f94fb55-rd8f5   1/1     Running            3          40d
myapp-deployment-558f94fb55-zzmpg   1/1     Running            3          40d
mypod                               1/1     Running            2          6d2h
myrs-2xk7k                          1/1     Running            0          4s
myrs-vmchf                          1/1     Running            0          6m54s
nginx-deployment-6f77f65499-8g24d   1/1     Running            3          39d
pod-demo                            2/2     Running            4          6d3h
readiness-exec                      1/1     Running            1          4d1h
#发现依然有两个副本处于Running状态，且之前删除的myrs-74ntr变为了myrs-2xk7k，说明这个副本已经被ReplicaSet控制器重建了。

欺骗ReplicaSet：

#我们将一个Pod的label修改为和myrs的label一样，这时候ReplicaSet会根据label判断现在有3个副本，不符合我们所定义的“replicas: 2”，为了达到我们定义的期望状态，ReplicaSet会删除一个副本。
[root@k8smaster data]# kubectl get pods --show-labels
NAME                                READY   STATUS             RESTARTS   AGE     LABELS
memleak-pod                         0/1     CrashLoopBackOff   32         141m    
myapp-deployment-558f94fb55-plk4v   1/1     Running            3          40d     app=myapp-deployment,pod-template-hash=558f94fb55
myapp-deployment-558f94fb55-rd8f5   1/1     Running            3          40d         app=myapp-deployment,pod-template-hash=558f94fb55
myapp-deployment-558f94fb55-zzmpg   1/1     Running            3          40d     app=myapp-deployment,pod-template-hash=558f94fb55
mypod                               1/1     Running            2          6d3h    
myrs-2xk7k                          1/1     Running            0          9m53s   app=myrs,environment=qa,release=canary
myrs-vmchf                          1/1     Running            0          16m     app=myrs,environment=qa,release=canary
nginx-deployment-6f77f65499-8g24d   1/1     Running            3          39d     app=nginx-deployment,pod-template-hash=6f77f65499
pod-demo                            2/2     Running            4          6d3h    
readiness-exec                      1/1     Running            1          4d1h    test=readiness-exec
#修改pod-demo的label与myrs相同。
[root@k8smaster data]# kubectl label pods pod-demo -n default app=myrs
pod/pod-demo labeled
[root@k8smaster data]# kubectl label pods pod-demo -n default environment=qa
pod/pod-demo labeled
[root@k8smaster data]# kubectl label pods pod-demo -n default release=canary
pod/pod-demo labeled
#发现原先的myrs-2xk7k已经被删除。
[root@k8smaster data]# kubectl get pods --show-labels
NAME                                READY   STATUS             RESTARTS   AGE    LABELS
memleak-pod                         0/1     CrashLoopBackOff   32         142m   
myapp-deployment-558f94fb55-plk4v   1/1     Running            3          40d    app=myapp-deployment,pod-template-hash=558f94fb55
myapp-deployment-558f94fb55-rd8f5   1/1     Running            3          40d    app=myapp-deployment,pod-template-hash=558f94fb55
myapp-deployment-558f94fb55-zzmpg   1/1     Running            3          40d    app=myapp-deployment,pod-template-hash=558f94fb55
mypod                               1/1     Running            2          6d3h   
myrs-vmchf                          1/1     Running            0          18m    app=myrs,environment=qa,release=canary
nginx-deployment-6f77f65499-8g24d   1/1     Running            3          39d    app=nginx-deployment,pod-template-hash=6f77f65499
pod-demo                            2/2     Running            4          6d3h   app=myrs,environment=qa,release=canary
readiness-exec                      1/1     Running            1          4d1h   test=readiness-exec
#我们再删除pod-demo。
[root@k8smaster data]# kubectl delete pod pod-demo 
pod "pod-demo" deleted
#发现ReplicaSet又调整为了我们用户期望的状态。
[root@k8smaster data]# kubectl get pods --show-labels
NAME                                READY   STATUS             RESTARTS   AGE    LABELS
memleak-pod                         0/1     CrashLoopBackOff   34         151m   
myapp-deployment-558f94fb55-plk4v   1/1     Running            3          40d    app=myapp-deployment,pod-template-hash=558f94fb55
myapp-deployment-558f94fb55-rd8f5   1/1     Running            3          40d    app=myapp-deployment,pod-template-hash=558f94fb55
myapp-deployment-558f94fb55-zzmpg   1/1     Running            3          40d    app=myapp-deployment,pod-template-hash=558f94fb55
mypod                               1/1     Running            2          6d3h   
myrs-vmchf                          1/1     Running            0          27m    app=myrs,environment=qa,release=canary
myrs-vn9gl                          1/1     Running            0          51s    app=myrs,environment=qa,release=canary
nginx-deployment-6f77f65499-8g24d   1/1     Running            3          39d    app=nginx-deployment,pod-template-hash=6f77f65499
readiness-exec                      1/1     Running            1          4d1h   test=readiness-exec

实时修改：

#实时扩展。
[root@k8smaster data]# kubectl edit rs myrs
修改为：
replicas: 5
保存退出
[root@k8smaster data]# kubectl edit rs myrs
replicaset.extensions/myrs edited
[root@k8smaster data]# kubectl get pods 
NAME                                READY   STATUS             RESTARTS   AGE
memleak-pod                         0/1     CrashLoopBackOff   36         160m
myapp-deployment-558f94fb55-plk4v   1/1     Running            3          40d
myapp-deployment-558f94fb55-rd8f5   1/1     Running            3          40d
myapp-deployment-558f94fb55-zzmpg   1/1     Running            3          40d
mypod                               1/1     Running            2          6d3h
myrs-dgblp                          1/1     Running            0          21s
myrs-fnznb                          1/1     Running            0          21s
myrs-vmchf                          1/1     Running            0          35m
myrs-vn9gl                          1/1     Running            0          9m36s
myrs-wcxkt                          1/1     Running            0          21s
nginx-deployment-6f77f65499-8g24d   1/1     Running            3          39d
readiness-exec                      1/1     Running            1          4d1h
#实时缩减
[root@k8smaster data]# kubectl edit rs myrs
修改为：
replicas: 2
保存退出
[root@k8smaster data]# kubectl edit rs myrs
replicaset.extensions/myrs edited
[root@k8smaster data]# kubectl get pods 
NAME                                READY   STATUS             RESTARTS   AGE
memleak-pod                         0/1     CrashLoopBackOff   36         161m
myapp-deployment-558f94fb55-plk4v   1/1     Running            3          40d
myapp-deployment-558f94fb55-rd8f5   1/1     Running            3          40d
myapp-deployment-558f94fb55-zzmpg   1/1     Running            3          40d
mypod                               1/1     Running            2          6d3h
myrs-dgblp                          1/1     Terminating        0          73s
myrs-fnznb                          1/1     Terminating        0          73s
myrs-vmchf                          1/1     Running            0          36m
myrs-vn9gl                          1/1     Running            0          10m
myrs-wcxkt                          1/1     Terminating        0          73s
nginx-deployment-6f77f65499-8g24d   1/1     Running            3          39d
readiness-exec                      1/1     Running            1          4d1h
#实时升级版本
[root@k8smaster data]# kubectl edit rs myrs
修改为：
- image: ikubernetes/myapp:v2
保存退出
[root@k8smaster data]# kubectl edit rs myrs
replicaset.extensions/myrs edited
[root@k8smaster data]# kubectl get rs -o wide
NAME                          DESIRED   CURRENT   READY   AGE   CONTAINERS        IMAGES                 SELECTOR
myapp-deployment-558f94fb55   3         3         3       40d   myapp             ikubernetes/myapp:v1   app=myapp-deployment,pod-template-hash=558f94fb55
myrs                          2         2         2       40m   myapp-container   ikubernetes/myapp:v2   app=myrs,release=canary
nginx-deployment-6f77f65499   1         1         1       39d   nginx             nginx                  app=nginx-deployment,pod-template-hash=6f77f65499
[root@k8smaster data]# kubectl get pods -o wide
NAME                                READY   STATUS             RESTARTS   AGE     IP             NODE       NOMINATED NODE   READINESS GATES
memleak-pod                         0/1     CrashLoopBackOff   42         3h27m   10.244.1.112   k8snode1              
myapp-deployment-558f94fb55-plk4v   1/1     Running            3          40d     10.244.2.103   k8snode2              
myapp-deployment-558f94fb55-rd8f5   1/1     Running            3          40d     10.244.2.104   k8snode2              
myapp-deployment-558f94fb55-zzmpg   1/1     Running            3          40d     10.244.1.110   k8snode1              
mypod                               1/1     Running            2          6d4h    10.244.2.105   k8snode2              
myrs-vmchf                          1/1     Running            0          83m     10.244.1.113   k8snode1              
myrs-vn9gl                          1/1     Running            0          56m     10.244.2.109   k8snode2              
nginx-deployment-6f77f65499-8g24d   1/1     Running            3          39d     10.244.1.109   k8snode1              
readiness-exec                      1/1     Running            1          4d2h    10.244.2.106   k8snode2              
#通过访问Pod发现，Pod并没有升级到V2版本。
[root@k8smaster data]# curl 10.244.1.113
Hello MyApp | Version: v1 | Pod Name
#删除这个Pod。
[root@k8smaster data]# kubectl delete pods myrs-vmchf
pod "myrs-vmchf" deleted
[root@k8smaster data]# kubectl get pods -o wide
NAME                                READY   STATUS             RESTARTS   AGE     IP             NODE       NOMINATED NODE   READINESS GATES
memleak-pod                         0/1     CrashLoopBackOff   42         3h29m   10.244.1.112   k8snode1              
myapp-deployment-558f94fb55-plk4v   1/1     Running            3          40d     10.244.2.103   k8snode2              
myapp-deployment-558f94fb55-rd8f5   1/1     Running            3          40d     10.244.2.104   k8snode2              
myapp-deployment-558f94fb55-zzmpg   1/1     Running            3          40d     10.244.1.110   k8snode1              
mypod                               1/1     Running            2          6d4h    10.244.2.105   k8snode2              
myrs-c9k2l                          1/1     Running            0          20s     10.244.1.114   k8snode1              
myrs-vn9gl                          1/1     Running            0          59m     10.244.2.109   k8snode2              
nginx-deployment-6f77f65499-8g24d   1/1     Running            3          39d     10.244.1.109   k8snode1              
readiness-exec                      1/1     Running            1          4d2h    10.244.2.106   k8snode2              
#访问重建的Pod，发现版本变成了V2，所以只有当Pod重建的时候才会应用模块中修改的内容。
[root@k8smaster data]# curl 10.244.1.114
Hello MyApp | Version: v2 | Pod Name

Deployment（控制更新节奏）：

功能：

• 扩容和缩容。
• 暂停和继续。
• 滚动升级和版本回滚。

Deployment配置清单主要字段：

apiVersion: apps/v1      #版本。
kind: Deployment        #类型。
metadata:               #元数据。
spec:                   #期望状态。
  minReadySeconds:      #新创建Pod准备好的最小时间，单位秒。
  replicas:             #副本数量，默认为1.
  selector:             #标签选择器。
  template:             #模板（必要字段）
    metadata:           #模板中的元数据。
    spec:               #模板期望状态。
  strategy:             #更新策略；用于将现有pod替换为新pod的部署策略。
    Recreate:           #重建更新。
    RollingUpdate:      #滚动更新。
      maxSurge:         #可以在所需数量的pod之上安排的最大pod数；例如：5、10%。
      maxUnavailable:   #更新期间可用的最大pod数。
  revisionHistoryLimit: #要保留以允许回滚的旧ReplicaSet的数量，默认10。
  paused:               #表示部署已暂停，部署控制器不处理部署。
  progressDeadlineSeconds:  #在执行此操作之前部署的最长时间被认为是失败的。
status:                 #实际状态

[root@k8smaster data]# vim deploy-demo.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: myapp-dep
  namespace: default
spec:
  replicas: 2
  selector:
    matchLabels:
      app: myapp
      release: beta
  template:
    metadata:
      labels:
        app: myapp
        release: beta
    spec:
      containers:
      - name: myapp
        image: ikubernetes/myapp:v1
        ports:
        - name: http
          containerPort: 80
[root@k8smaster data]# kubectl apply -f deploy-demo.yaml 
deployment.apps/myapp-dep created
[root@k8smaster data]# kubectl get pods
NAME                                READY   STATUS             RESTARTS   AGE
memleak-pod                         0/1     CrashLoopBackOff   71         22h
myapp-dep-678d8f65bc-bg5tk          1/1     Running            0          2m15s
myapp-dep-678d8f65bc-n7dhn          1/1     Running            0          2m15s
myapp-deployment-558f94fb55-plk4v   1/1     Running            4          40d
myapp-deployment-558f94fb55-rd8f5   1/1     Running            4          40d
myapp-deployment-558f94fb55-zzmpg   1/1     Running            4          40d
mypod                               1/1     Running            3          6d23h
myrs-c9k2l                          1/1     Running            1          19h
myrs-vn9gl                          1/1     Running            1          20h
nginx-deployment-6f77f65499-8g24d   1/1     Running            4          40d
readiness-exec                      1/1     Running            2          4d21h
[root@k8smaster data]# kubectl get deploy
NAME               READY   UP-TO-DATE   AVAILABLE   AGE
myapp-dep          2/2     2            2           2m55s
myapp-deployment   3/3     3            3           40d
nginx-deployment   1/1     1            1           40d
[root@k8smaster data]# kubectl get rs
NAME                          DESIRED   CURRENT   READY   AGE
myapp-dep-678d8f65bc          2         2         2       3m19s
myapp-deployment-558f94fb55   3         3         3       40d
myrs                          2         2         2       20h
nginx-deployment-6f77f65499   1         1         1       40d
[root@k8smaster data]# kubectl describe deploy myapp-dep
Name:                   myapp-dep
Namespace:              default
CreationTimestamp:      Wed, 11 Dec 2019 14:23:44 +0800
Labels:                 
Annotations:            deployment.kubernetes.io/revision: 1
                        kubectl.kubernetes.io/last-applied-configuration:
                        {"apiVersion":"apps/v1","kind":"Deployment","metadata":{"annotations":{},"name":"myapp-dep","namespace":"default"},"spec":{"replicas":2,"s...
Selector:               app=myapp,release=beta
Replicas:               2 desired | 2 updated | 2 total | 2 available | 0 unavailable
StrategyType:           RollingUpdate
MinReadySeconds:        0
RollingUpdateStrategy:  25% max unavailable, 25% max surge
Pod Template:
    Labels:  app=myapp
            release=beta
Containers:
    myapp:
    Image:        ikubernetes/myapp:v1
    Port:         80/TCP
    Host Port:    0/TCP
    Environment:  
    Mounts:       
  Volumes:        
Conditions:
  Type           Status  Reason
  ----           ------  ------
  Available      True    MinimumReplicasAvailable
  Progressing    True    NewReplicaSetAvailable
OldReplicaSets:  
NewReplicaSet:   myapp-dep-678d8f65bc (2/2 replicas created)
Events:
  Type    Reason             Age   From                   Message
  ----    ------             ----  ----                   -------
  Normal  ScalingReplicaSet  6m    deployment-controller  Scaled up replica set myapp-dep-678d8f65bc to 2

滚动更新：

#监控pod状态。
[root@k8smaster data]# kubectl get pods -l app=myapp -w
#去修改配置文件。
[root@k8smaster ~]# cd /data/
[root@k8smaster data]# vim deploy-demo.yaml 
修改为：
image: ikubernetes/myapp:v2
#应用。
[root@k8smaster data]# kubectl apply -f deploy-demo.yaml 
deployment.apps/myapp-dep configured
#查看监控
[root@k8smaster data]# kubectl get pods -l app=myapp -w
NAME                         READY   STATUS    RESTARTS   AGE
myapp-dep-678d8f65bc-bg5tk   1/1     Running   0          10m
myapp-dep-678d8f65bc-n7dhn   1/1     Running   0          10m
myapp-dep-6c458b4c54-kmq46   0/1     Pending   0          0s
myapp-dep-6c458b4c54-kmq46   0/1     Pending   0          0s
myapp-dep-6c458b4c54-kmq46   0/1     ContainerCreating   0          0s
myapp-dep-6c458b4c54-kmq46   1/1     Running             0          3s
myapp-dep-678d8f65bc-bg5tk   1/1     Terminating         0          11m
myapp-dep-6c458b4c54-sdmmv   0/1     Pending             0          0s
myapp-dep-6c458b4c54-sdmmv   0/1     Pending             0          0s
myapp-dep-6c458b4c54-sdmmv   0/1     ContainerCreating   0          0s
myapp-dep-678d8f65bc-bg5tk   0/1     Terminating         0          11m
myapp-dep-6c458b4c54-sdmmv   1/1     Running             0          1s
myapp-dep-678d8f65bc-n7dhn   1/1     Terminating         0          11m
myapp-dep-678d8f65bc-n7dhn   0/1     Terminating         0          11m
myapp-dep-678d8f65bc-bg5tk   0/1     Terminating         0          11m
myapp-dep-678d8f65bc-bg5tk   0/1     Terminating         0          11m
myapp-dep-678d8f65bc-n7dhn   0/1     Terminating         0          11m
myapp-dep-678d8f65bc-n7dhn   0/1     Terminating         0          11m

#查看rs，发现多了一个v2版本的rs模板
[root@k8smaster data]# kubectl get rs -o wide
NAME                          DESIRED   CURRENT   READY   AGE    CONTAINERS        IMAGES                 SELECTOR
myapp-dep-678d8f65bc          0         0         0       13m    myapp             ikubernetes/myapp:v1   app=myapp,pod-template-hash=678d8f65bc,release=beta
myapp-dep-6c458b4c54          2         2         2       2m9s   myapp             ikubernetes/myapp:v2   app=myapp,pod-template-hash=6c458b4c54,release=beta
myapp-deployment-558f94fb55   3         3         3       40d    myapp             ikubernetes/myapp:v1   app=myapp-deployment,pod-template-hash=558f94fb55
myrs                          2         2         2       20h    myapp-container   ikubernetes/myapp:v2   app=myrs,release=canary
nginx-deployment-6f77f65499   1         1         1       40d    nginx             nginx                  app=nginx-deployment,pod-template-hash=6f77f65499
#查看滚动历史。
[root@k8smaster data]# kubectl rollout history deployment myapp-dep
deployment.extensions/myapp-dep 
REVISION  CHANGE-CAUSE
1         
2         

通过patch方式来更新myapp-dep：

#修改replicas为5。
[root@k8smaster data]# kubectl patch deployment myapp-dep -p '{"spec":{"replicas":5}}'
deployment.extensions/myapp-dep patched
[root@k8smaster data]# kubectl get pods
NAME                                READY   STATUS             RESTARTS   AGE
memleak-pod                         0/1     CrashLoopBackOff   74         23h
myapp-dep-6c458b4c54-g4sd6          1/1     Running            0          3s
myapp-dep-6c458b4c54-kmq46          1/1     Running            0          9m12s
myapp-dep-6c458b4c54-mfq76          1/1     Running            0          3s
myapp-dep-6c458b4c54-sdmmv          1/1     Running            0          9m9s
myapp-dep-6c458b4c54-z7sj6          1/1     Running            0          3s
myapp-deployment-558f94fb55-plk4v   1/1     Running            4          40d
myapp-deployment-558f94fb55-rd8f5   1/1     Running            4          40d
myapp-deployment-558f94fb55-zzmpg   1/1     Running            4          40d
mypod                               1/1     Running            3          6d23h
myrs-c9k2l                          1/1     Running            1          19h
myrs-vn9gl                          1/1     Running            1          20h
nginx-deployment-6f77f65499-8g24d   1/1     Running            4          40d
readiness-exec                      1/1     Running            2          4d21h

#修改更新策略：maxSurge为1，maxUnavailable为0。
[root@k8smaster data]# kubectl patch deployment myapp-dep -p '{"spec":{"strategy":{"rollingUpdate":{"maxSurge":1,"maxUnavailable":0}}}}'
deployment.extensions/myapp-dep patched
[root@k8smaster data]# kubectl describe deployment myapp-dep
Name:                   myapp-dep
Namespace:              default
CreationTimestamp:      Wed, 11 Dec 2019 14:23:44 +0800
Labels:                 app=myapp
                        release=beta
Annotations:            deployment.kubernetes.io/revision: 2
                        kubectl.kubernetes.io/last-applied-configuration:
                        {"apiVersion":"apps/v1","kind":"Deployment","metadata":{"annotations":{},"name":"myapp-dep","namespace":"default"},"spec":{"replicas":2,"s...
Selector:               app=myapp,release=beta
Replicas:               5 desired | 5 updated | 5 total | 5 available | 0 unavailable
StrategyType:           RollingUpdate
MinReadySeconds:        0
RollingUpdateStrategy:  0 max unavailable, 1 max surge
Pod Template:
    Labels:  app=myapp
            release=beta
Containers:
  myapp:
    Image:        ikubernetes/myapp:v2
    Port:         80/TCP
    Host Port:    0/TCP
    Environment:  
    Mounts:       
Volumes:        
Conditions:
  Type           Status  Reason
  ----           ------  ------
  Progressing    True    NewReplicaSetAvailable
  Available      True    MinimumReplicasAvailable
  OldReplicaSets:  
  NewReplicaSet:   myapp-dep-6c458b4c54 (5/5 replicas created)
Events:
  Type    Reason             Age    From                   Message
  ----    ------             ----   ----                   -------
  Normal  ScalingReplicaSet  26m    deployment-controller  Scaled up replica set myapp-dep-678d8f65bc to 2
  Normal  ScalingReplicaSet  14m    deployment-controller  Scaled up replica set myapp-dep-6c458b4c54 to 1
  Normal  ScalingReplicaSet  14m    deployment-controller  Scaled down replica set myapp-dep-678d8f65bc to 1
  Normal  ScalingReplicaSet  14m    deployment-controller  Scaled up replica set myapp-dep-6c458b4c54 to 2
  Normal  ScalingReplicaSet  14m    deployment-controller  Scaled down replica set myapp-dep-678d8f65bc to 0
  Normal  ScalingReplicaSet  5m38s  deployment-controller  Scaled up replica set myapp-dep-6c458b4c54 to 5

#监控Pod状态。
[root@k8smaster data]# kubectl get pods -l app=myapp -w
NAME                         READY   STATUS    RESTARTS   AGE
myapp-dep-6c458b4c54-g4sd6   1/1     Running   0          10m
myapp-dep-6c458b4c54-kmq46   1/1     Running   0          19m
myapp-dep-6c458b4c54-mfq76   1/1     Running   0          10m
myapp-dep-6c458b4c54-sdmmv   1/1     Running   0          19m
myapp-dep-6c458b4c54-z7sj6   1/1     Running   0          10m

#对镜像版本进行更新，并且暂停更新。
[root@k8smaster data]# kubectl set image deployment myapp-dep myapp=ikubernetes/myapp:v3  && kubectl rollout pause deployment myapp-dep
deployment.extensions/myapp-dep image updated
deployment.extensions/myapp-dep paused
[root@k8smaster data]# kubectl get pods -l app=myapp -w
NAME                         READY   STATUS    RESTARTS   AGE
myapp-dep-6c458b4c54-g4sd6   1/1     Running   0          10m
myapp-dep-6c458b4c54-kmq46   1/1     Running   0          19m
myapp-dep-6c458b4c54-mfq76   1/1     Running   0          10m
myapp-dep-6c458b4c54-sdmmv   1/1     Running   0          19m
myapp-dep-6c458b4c54-z7sj6   1/1     Running   0          10m
myapp-dep-6c8cbfb497-zmk69   0/1     Pending   0          0s
myapp-dep-6c8cbfb497-zmk69   0/1     Pending   0          0s
myapp-dep-6c8cbfb497-zmk69   0/1     ContainerCreating   0          0s
myapp-dep-6c8cbfb497-zmk69   1/1     Running             0          3s

#监控deployment控制器
[root@k8smaster data]# kubectl rollout status deployment myapp-dep
Waiting for deployment "myapp-dep" rollout to finish: 1 out of 5 new replicas have been updated...

#取消暂停
[root@k8smaster ~]# kubectl rollout resume deployment myapp-dep
deployment.extensions/myapp-dep resumed

#查看Pod状态
[root@k8smaster data]# kubectl get pods -l app=myapp -w
NAME                         READY   STATUS    RESTARTS   AGE
myapp-dep-6c458b4c54-g4sd6   1/1     Running   0          10m
myapp-dep-6c458b4c54-kmq46   1/1     Running   0          19m
myapp-dep-6c458b4c54-mfq76   1/1     Running   0          10m
myapp-dep-6c458b4c54-sdmmv   1/1     Running   0          19m
myapp-dep-6c458b4c54-z7sj6   1/1     Running   0          10m
myapp-dep-6c8cbfb497-zmk69   0/1     Pending   0          0s
myapp-dep-6c8cbfb497-zmk69   0/1     Pending   0          0s
myapp-dep-6c8cbfb497-zmk69   0/1     ContainerCreating   0          0s
myapp-dep-6c8cbfb497-zmk69   1/1     Running             0          3s
myapp-dep-6c458b4c54-g4sd6   1/1     Terminating         0          15m
myapp-dep-6c8cbfb497-89nwn   0/1     Pending             0          0s
myapp-dep-6c8cbfb497-89nwn   0/1     Pending             0          0s
myapp-dep-6c8cbfb497-89nwn   0/1     ContainerCreating   0          0s
myapp-dep-6c458b4c54-g4sd6   0/1     Terminating         0          15m
myapp-dep-6c8cbfb497-89nwn   1/1     Running             0          3s
myapp-dep-6c458b4c54-mfq76   1/1     Terminating         0          15m
myapp-dep-6c8cbfb497-sbdpb   0/1     Pending             0          0s
myapp-dep-6c8cbfb497-sbdpb   0/1     Pending             0          0s
myapp-dep-6c8cbfb497-sbdpb   0/1     ContainerCreating   0          0s
myapp-dep-6c458b4c54-mfq76   0/1     Terminating         0          15m
myapp-dep-6c8cbfb497-sbdpb   1/1     Running             0          1s
myapp-dep-6c458b4c54-z7sj6   1/1     Terminating         0          15m
myapp-dep-6c8cbfb497-6zhcr   0/1     Pending             0          0s
myapp-dep-6c8cbfb497-6zhcr   0/1     Pending             0          0s
myapp-dep-6c458b4c54-g4sd6   0/1     Terminating         0          15m
myapp-dep-6c458b4c54-g4sd6   0/1     Terminating         0          15m
myapp-dep-6c8cbfb497-6zhcr   0/1     ContainerCreating   0          0s
myapp-dep-6c8cbfb497-6zhcr   1/1     Running             0          1s
myapp-dep-6c458b4c54-sdmmv   1/1     Terminating         0          24m
myapp-dep-6c8cbfb497-wh6v8   0/1     Pending             0          0s
myapp-dep-6c8cbfb497-wh6v8   0/1     Pending             0          0s
myapp-dep-6c458b4c54-z7sj6   0/1     Terminating         0          15m
myapp-dep-6c8cbfb497-wh6v8   0/1     ContainerCreating   0          1s
myapp-dep-6c458b4c54-sdmmv   0/1     Terminating         0          24m
myapp-dep-6c8cbfb497-wh6v8   1/1     Running             0          2s
myapp-dep-6c458b4c54-kmq46   1/1     Terminating         0          24m
myapp-dep-6c458b4c54-kmq46   0/1     Terminating         0          24m
myapp-dep-6c458b4c54-z7sj6   0/1     Terminating         0          15m
myapp-dep-6c458b4c54-z7sj6   0/1     Terminating         0          15m
myapp-dep-6c458b4c54-sdmmv   0/1     Terminating         0          24m
myapp-dep-6c458b4c54-sdmmv   0/1     Terminating         0          24m
myapp-dep-6c458b4c54-kmq46   0/1     Terminating         0          24m
myapp-dep-6c458b4c54-kmq46   0/1     Terminating         0          24m
myapp-dep-6c458b4c54-mfq76   0/1     Terminating         0          15m
myapp-dep-6c458b4c54-mfq76   0/1     Terminating         0          15m

#监控Deployment控制器：
[root@k8smaster data]# kubectl rollout status deployment myapp-dep
Waiting for deployment "myapp-dep" rollout to finish: 1 out of 5 new replicas have been updated...
Waiting for deployment spec update to be observed...
Waiting for deployment spec update to be observed...
Waiting for deployment "myapp-dep" rollout to finish: 1 out of 5 new replicas have been updated...
Waiting for deployment "myapp-dep" rollout to finish: 1 out of 5 new replicas have been updated...
Waiting for deployment "myapp-dep" rollout to finish: 2 out of 5 new replicas have been updated...
Waiting for deployment "myapp-dep" rollout to finish: 2 out of 5 new replicas have been updated...
Waiting for deployment "myapp-dep" rollout to finish: 2 out of 5 new replicas have been updated...
Waiting for deployment "myapp-dep" rollout to finish: 3 out of 5 new replicas have been updated...
Waiting for deployment "myapp-dep" rollout to finish: 3 out of 5 new replicas have been updated...
Waiting for deployment "myapp-dep" rollout to finish: 3 out of 5 new replicas have been updated...
Waiting for deployment "myapp-dep" rollout to finish: 4 out of 5 new replicas have been updated...
Waiting for deployment "myapp-dep" rollout to finish: 4 out of 5 new replicas have been updated...
Waiting for deployment "myapp-dep" rollout to finish: 4 out of 5 new replicas have been updated...
Waiting for deployment "myapp-dep" rollout to finish: 1 old replicas are pending termination...
Waiting for deployment "myapp-dep" rollout to finish: 1 old replicas are pending termination...
deployment "myapp-dep" successfully rolled out

#查看rs，发现多了一个v3版本的rs模板
[root@k8smaster ~]# kubectl get rs -o wide
NAME                          DESIRED   CURRENT   READY   AGE     CONTAINERS        IMAGES                 SELECTOR
myapp-dep-678d8f65bc          0         0         0       40m     myapp             ikubernetes/myapp:v1   app=myapp,pod-template-hash=678d8f65bc,release=beta
myapp-dep-6c458b4c54          0         0         0       29m     myapp             ikubernetes/myapp:v2   app=myapp,pod-template-hash=6c458b4c54,release=beta
myapp-dep-6c8cbfb497          5         5         5       8m28s   myapp             ikubernetes/myapp:v3   app=myapp,pod-template-hash=6c8cbfb497,release=beta
myapp-deployment-558f94fb55   3         3         3       40d     myapp             ikubernetes/myapp:v1   app=myapp-deployment,pod-template-hash=558f94fb55
myrs                          2         2         2       21h     myapp-container   ikubernetes/myapp:v2   app=myrs,release=canary
nginx-deployment-6f77f65499   1         1         1       40d     nginx             nginx                  app=nginx-deployment,pod-template-hash=6f77f65499

回滚：

#查看历史版本信息。
[root@k8smaster ~]# kubectl rollout history deployment myapp-dep
deployment.extensions/myapp-dep 
REVISION  CHANGE-CAUSE
1         
2         
3         

#指定需要回滚到的版本。
[root@k8smaster ~]# kubectl rollout undo deployment myapp-dep --to-revision=1
deployment.extensions/myapp-dep rolled back

#发现5个副本又都跑在了V1版本的RS模板上。
[root@k8smaster ~]# kubectl get rs -o wide
NAME                          DESIRED   CURRENT   READY   AGE   CONTAINERS        IMAGES                 SELECTOR
myapp-dep-678d8f65bc          5         5         5       47m   myapp             ikubernetes/myapp:v1   app=myapp,pod-template-hash=678d8f65bc,release=beta
myapp-dep-6c458b4c54          0         0         0       36m   myapp             ikubernetes/myapp:v2   app=myapp,pod-template-hash=6c458b4c54,release=beta
myapp-dep-6c8cbfb497          0         0         0       15m   myapp             ikubernetes/myapp:v3   app=myapp,pod-template-hash=6c8cbfb497,release=beta
myapp-deployment-558f94fb55   3         3         3       40d   myapp             ikubernetes/myapp:v1   app=myapp-deployment,pod-template-hash=558f94fb55
myrs                          2         2         2       21h   myapp-container   ikubernetes/myapp:v2   app=myrs,release=canary
nginx-deployment-6f77f65499   1         1         1       40d   nginx             nginx                  app=nginx-deployment,pod-template-hash=6f77f65499

DaemontSet：

DaemonSet用来保证每个节点上都运行一个容器副本，常用来部署一些集群日志，监控或者其他系统管理应用。

应用范围：

• 日志收集。
• 系统监控。
• 系统程序。

DaemontSet配置清单主要字段：

apiVersion: apps/v1         #版本。
kind: DaemontSet            #类型。
metadata:                   #元数据。
spec:                       #期望状态。
  minReadySeconds:          #新创建Pod准备好的最小时间，单位秒。
  selector:                 #标签选择器。
  template:                 #模板（必要字段）
    metadata:               #模板的元数据。
    spec:                   #模板的期望状态。
  revisionHistoryLimit:     #要保留以允许回滚的旧ReplicaSet的数量，默认10。
  updateStrategy:           #用新pod替换现有DaemonSet pod的更新策略。
status:                     #实际状态。

#创建一个DaemonSet
[root@k8smaster data]# vim ds-demo.yaml 
apiVersion: apps/v1
kind: DaemonSet
metadata:
  name: filebeat-ds
  namespace: default
spec:
  selector:
    matchLabels:
      app: filebeat
      release: stable
  template:
    metadata:
      labels:
        app: filebeat
        release: stable
    spec:
      containers:
      - name: filebeat
        image: ikubernetes/filebeat:5.6.5-alpine
        env:
        - name: REDIS_HOST
          value: redis.default.svc.cluster.local
        - name: REDIS_LOG_LEVEL
          value: info
[root@k8smaster data]# kubectl apply -f ds-demo.yaml 
daemonset.apps/filebeat-ds created
[root@k8smaster data]# kubectl get pods
NAME                                READY   STATUS             RESTARTS   AGE
filebeat-ds-2jtgt                   1/1     Running            0          3m52s
filebeat-ds-bpbcd                   1/1     Running            0          3m52s
memleak-pod                         0/1     CrashLoopBackOff   102        45h
myrs-c9k2l                          1/1     Running            2          42h
myrs-vn9gl                          1/1     Running            2          43h
nginx-deployment-6f77f65499-8g24d   1/1     Running            5          41d
readiness-exec                      1/1     Running            3          5d20h
[root@k8smaster data]# kubectl exec -it filebeat-ds-2jtgt -- /bin/sh
/ # ps aux
PID   USER     TIME   COMMAND
    1 root       0:00 /usr/local/bin/filebeat -e -c /etc/filebeat/filebeat.yml
    12 root       0:00 /bin/sh
    17 root       0:00 ps aux

DaemonSet动态版本升级：

[root@k8smaster data]# kubectl set image daemonsets filebeat-ds filebeat=ikubernetes/filebeat:5.6.6-alpine
daemonset.extensions/filebeat-ds image updated
[root@k8smaster data]# kubectl get ds -o wide
NAME          DESIRED   CURRENT   READY   UP-TO-DATE   AVAILABLE   NODE SELECTOR   AGE     CONTAINERS   IMAGES                              SELECTOR
filebeat-ds   2         2         1       1            1                     7m38s   filebeat     ikubernetes/filebeat:5.6.6-alpine   app=filebeat,release=stable

Job：

 Job控制器用来运行一次性任务，容器中的进程再正常运行结束后不会对其进行重启操作，而是将Pod处于“Completed”状态。

 Job控制器的对象有两种分别是但工作列队的串行Job和多工作列队的并行Job。

#创建一个Job
[root@k8smaster data]# vim job-demo.yaml
apiVersion: batch/v1
kind: Job
metadata:
  name: myjob
spec:
  template:
    metadata:
      name: myapp-Job
    spec:
      containers:
      - name: hello
        image: busybox
        command: ["echo","hello Job"]
      restartPolicy: Never
[root@k8smaster data]# kubectl apply -f job-demo.yaml 
job.batch/myjob created
[root@k8smaster data]# kubectl get job
NAME    COMPLETIONS   DURATION   AGE
myjob   1/1           7s         12s

#创建一个并行Job
[root@k8smaster data]# kubectl delete -f job-demo.yaml 
job.batch "myjob" deleted
[root@k8smaster data]# vim job-demo.yaml 
apiVersion: batch/v1
kind: Job
metadata:
  name: myjob
spec:
  parallelism: 2  #一次完成两个。
  completions: 5  #一共完成六个。
  template:
    metadata:
      name: myapp-Job
    spec:
      containers:
      - name: hello
        image: busybox
        command: ["echo","hello Job"]
      restartPolicy: Never
[root@k8smaster data]# kubectl apply -f job-demo.yaml 
job.batch/myjob created
[root@k8smaster data]# kubectl get jobs
NAME    COMPLETIONS   DURATION   AGE
myjob   2/5           3s         3s
[root@k8smaster data]# kubectl get jobs
NAME    COMPLETIONS   DURATION   AGE
myjob   5/5           4s         9s

• 将parallelism字段属性值设置为1，并设置任务数字段” completions”属性值，便能够让pod控制器以串行方式运行多任务。
• 如果设置parallelism属性值大于等于2，且completions的属性值为1，则为并行任务，completions的属性值大于等于2则为串行多任务。
• activeDeadlineSeconds：用于为其指定最大活动时间的长度，超出将被终止。
• 将作业标记为失败状态之前的重试次数，默认为6。

CronJob：

CronJob控制器用来管理Job控制器资源的运行实际，CronJob控制器可以周期性的执行一些任务。类似于Linux的Crontab。

CronJob控制器主要字段：

• jobTemplate：用于为CronJob控制器生成job对象（必选）。
• schedule：用于为cron格式的作业调度运行的时间的（必选）。
• concurrencyPolicy：并发执行策略，定义前一次作业运行未完成是是否以及如何运行后一次作业，值有Allow和Forbid。
• failedJobHistoryLimit：用来为失败的任务执行保留历史记录数。
• successfulJobHistoryLimit：用来为成功的任务执行保留的历史记录数。
• startingDeadlineSeconds：因各种原因缺乏执行作业的时间点所导致的启动作业错误的超长时间，会被记录在错误历史记录。
• suspend：是否挂起后续的任务执行，默认为false。

#定义一个CronJob。
[root@k8smaster data]# kubectl delete -f job-demo.yaml 
job.batch   "myjob" deleted
[root@k8smaster data]# cp job-demo.yaml  conrjob-demo.yaml
[root@k8smaster data]# vim conrjob-demo.yaml 
apiVersion: batch/v2alpha1
kind: CronJob
metadata:
  name: hello
spec:
  schedule: "*/1 * * * *"
  jobTemplate:
    spec:
      template:
        spec:
          containers:
          - name: hello
            image: busybox
            command: ["echo","hello job"]
          restartPolicy: OnFailure
[root@k8smaster data]# vim /etc/kubernetes/manifests/kube-apiserver.yaml 
在第14行添加：
    - --runtime-config=batch/v2alpha1=true
[root@k8smaster data]# systemctl restart kubelet.service 
[root@k8smaster data]# kubectl api-versions
admissionregistration.k8s.io/v1beta1
apiextensions.k8s.io/v1beta1
apiregistration.k8s.io/v1
apiregistration.k8s.io/v1beta1
apps/v1
apps/v1beta1
apps/v1beta2
authentication.k8s.io/v1
authentication.k8s.io/v1beta1
authorization.k8s.io/v1
authorization.k8s.io/v1beta1
autoscaling/v1
autoscaling/v2beta1
autoscaling/v2beta2
batch/v1
batch/v1beta1
batch/v2alpha1     #找到了batch/v2alpha1，说明添加成功。
certificates.k8s.io/v1beta1
coordination.k8s.io/v1
coordination.k8s.io/v1beta1
events.k8s.io/v1beta1
extensions/v1beta1
networking.k8s.io/v1
networking.k8s.io/v1beta1
node.k8s.io/v1beta1
policy/v1beta1
rbac.authorization.k8s.io/v1
rbac.authorization.k8s.io/v1beta1
scheduling.k8s.io/v1
scheduling.k8s.io/v1beta1
storage.k8s.io/v1
storage.k8s.io/v1beta1
v1
[root@k8smaster data]# kubectl apply -f conrjob-demo.yaml
cronjob.batch/hello created
[root@k8smaster data]# kubectl get cronjobs.batch
NAME    SCHEDULE      SUSPEND   ACTIVE   LAST SCHEDULE   AGE
hello   */1 * * * *   False     1        7s              2m36s
[root@k8smaster ~]# kubectl get job
NAME               COMPLETIONS   DURATION   AGE
hello-1576131060   1/1           108s       3m3s
hello-1576131120   1/1           27s        2m3s
hello-1576131180   1/1           2s         63s
hello-1576131240   1/1           2s         2s
[root@k8smaster data]# kubectl logs hello-1576131240