《Kubernetes进阶实战》第五章《Pod控制器》

「爱情、让人受尽委屈。」 2022-03-26 04:37 259阅读 0赞

## Pod控制器 ##

**ReplicaSet：创建一定数量的pod，支持扩缩容  
主要有三个组件：1，用户期望的pod副本 2，标签选择器 3.如果pod不够怎么办，扩建  
Pod资源模板可以帮助用户新建  
Deployment可以比ReplicaSet更加强大，增加声明式配置和升级后的回滚，是目前最好的Pod控制器  
DaemonSet：系统级的Pod，只能在node上运行一个，每个集群精确运行一个  
Job：只能执行运行一次的，比如这个程序运行完了，这个容器就没有用了  
CronJob：周期性运行Job和CronJob都是不用长期运行的容器  
StatetufulSet：运行mysql，redis等有状态的应用  
有状态的运维任务时很困难的，比如mysql和redis集群，一般转换成脚本，有状态的应用托管到kubernetes上是很难的**

##  **演示ReplicaSet在更新中显现出的功能** ##

[root@master ~]# cd mainfests/
    [root@master mainfests]# vim rs-rep.yaml 
    [root@master mainfests]# cat rs-rep.yaml
    apiVersion: apps/v1
    kind: ReplicaSet
    metadata:
      name: myapp
      namespace: default
    spec:
      replicas: 2
      selector:
        matchLabels:
          app: myapp
          release: canary
      template:
        metadata:
          name: myapp-pod
          labels:
            app: myapp
            release: canary
            environment: qa
        spec:
          containers:
          - name: myapp-container
            image: ikubernetes/myapp:v1
            ports:
            - name: http
              containerPort: 80
    [root@master mainfests]# kubectl create -f rs-rep.yaml 
    replicaset.apps/myapp created
    [root@master mainfests]# kubectl get pod
    NAME                            READY   STATUS             RESTARTS   AGE
    client                          0/1     Error              0          23h
    liveness-exec-pod               0/1     CrashLoopBackOff   14         19h
    myapp-65899575cd-6p6qk          1/1     Running            1          22h
    myapp-cd4wf                     1/1     Running            0          5s
    myapp-mmjjx                     1/1     Running            0          5s
    nginx-deploy-84cbfc56b6-h5h7x   1/1     Running            1          23h
    [root@master mainfests]# kubectl get rs
    NAME                      DESIRED   CURRENT   READY   AGE
    myapp                     2         2         2       83s
    myapp-65899575cd          1         1         1       22h
    myapp-9b4987d5            0         0         0       22h
    nginx-deploy-84cbfc56b6   1         1         1       23h
    获取创建的Pod的详细信息
    [root@master mainfests]# kubectl describe pods myapp-cd4wf
    Name:               myapp-cd4wf
    Namespace:          default
    Priority:           0
    PriorityClassName:  <none>
    Node:               node01/10.0.0.101
    Start Time:         Fri, 22 Feb 2019 09:01:10 +0800
    Labels:             app=myapp
                        environment=qa
                        release=canary
    Annotations:        <none>
    Status:             Running
    IP:                 10.244.1.19
    Controlled By:      ReplicaSet/myapp
    Containers:
      myapp-container:
        Container ID:   docker://f9c36b45762164e23ba7d7d613054d93a4303ca8f5872e876b313cfa2daeeff6
        Image:          ikubernetes/myapp:v1
        Image ID:       docker-pullable://ikubernetes/myapp@sha256:9c3dc30b5219788b2b8a4b065f548b922a34479577befb54b03330999d30d513
        Port:           80/TCP
        Host Port:      0/TCP
        State:          Running
          Started:      Fri, 22 Feb 2019 09:01:11 +0800
        Ready:          True
        Restart Count:  0
        Environment:    <none>
        Mounts:
          /var/run/secrets/kubernetes.io/serviceaccount from default-token-h8l2m (ro)
    Conditions:
      Type              Status
      Initialized       True 
      Ready             True 
      ContainersReady   True 
      PodScheduled      True 
    Volumes:
      default-token-h8l2m:
        Type:        Secret (a volume populated by a Secret)
        SecretName:  default-token-h8l2m
        Optional:    false
    QoS Class:       BestEffort
    Node-Selectors:  <none>
    Tolerations:     node.kubernetes.io/not-ready:NoExecute for 300s
                     node.kubernetes.io/unreachable:NoExecute for 300s
    Events:
      Type    Reason     Age   From               Message
      ----    ------     ----  ----               -------
      Normal  Scheduled  114s  default-scheduler  Successfully assigned default/myapp-cd4wf to node01
      Normal  Pulled     113s  kubelet, node01    Container image "ikubernetes/myapp:v1" already present on machine
      Normal  Created    113s  kubelet, node01    Created container
      Normal  Started    113s  kubelet, node01    Started container
    
    [root@master mainfests]# curl 10.244.1.19
    Hello MyApp | Version: v1 | <a href="hostname.html">Pod Name</a>
    [root@master mainfests]# curl 10.244.1.19/hostname.html
    myapp-cd4wf
    [root@master mainfests]# kubectl get pods
    NAME                            READY   STATUS    RESTARTS   AGE
    myapp-65899575cd-6p6qk          1/1     Running   1          22h
    myapp-cd4wf                     1/1     Running   0          3m8s
    myapp-mmjjx                     1/1     Running   0          3m8s
    nginx-deploy-84cbfc56b6-h5h7x   1/1     Running   1          23h
    删除一个Pod，他会自动创建一个
    [root@master mainfests]# kubectl delete pods myapp-cd4wf
    pod "myapp-cd4wf" deleted
    [root@master mainfests]# kubectl get pod
    NAME                            READY   STATUS             RESTARTS   AGE
    myapp-4tkhm                     1/1     Running            0          6s
    myapp-65899575cd-6p6qk          1/1     Running            1          22h
    myapp-mmjjx                     1/1     Running            0          3m27s
    nginx-deploy-84cbfc56b6-h5h7x   1/1     Running            1          23h
    [root@master mainfests]# kubectl get pods --show-labels
    NAME                            READY   STATUS             RESTARTS   AGE     LABELS
    myapp-4tkhm                     1/1     Running            0          72s     app=myapp,environment=qa,release=canary
    myapp-65899575cd-6p6qk          1/1     Running            1          22h     pod-template-hash=65899575cd,run=myapp
    myapp-mmjjx                     1/1     Running            0          4m33s   app=myapp,environment=qa,release=canary
    
    自动扩容：将myapp扩容到10个
    [root@master ~]# kubectl edit rs myapp
    spec:
      replicas: 10
    [root@master mainfests]# kubectl edit rs myapp
    replicaset.extensions/myapp edited
    监控pod创建
    [root@master mainfests]# kubectl get pods -w
    NAME                            READY   STATUS              RESTARTS   AGE
    myapp-4tkhm                     1/1     Running             0          4m22s
    myapp-65899575cd-6p6qk          1/1     Running             1          22h
    myapp-dh45q                     0/1     ContainerCreating   0          6s
    myapp-g6tgq                     0/1     ContainerCreating   0          6s
    myapp-k5xtm                     0/1     ContainerCreating   0          6s
    myapp-mmjjx                     1/1     Running             0          7m43s
    myapp-mpb79                     0/1     ContainerCreating   0          6s
    myapp-pbttb                     0/1     ContainerCreating   0          6s
    myapp-qnmnb                     0/1     ContainerCreating   0          6s
    myapp-r4ldv                     0/1     ContainerCreating   0          6s
    myapp-zmzhn                     0/1     ContainerCreating   0          6s
    nginx-deploy-84cbfc56b6-h5h7x   1/1     Running             1          23h
    myapp-g6tgq   1/1   Running   0     58s
    myapp-mpb79   1/1   Running   0     58s
    myapp-k5xtm   1/1   Running   0     58s
    myapp-dh45q   1/1   Running   0     58s
    myapp-qnmnb   1/1   Running   0     60s
    myapp-r4ldv   1/1   Running   0     60s
    myapp-zmzhn   1/1   Running   0     60s
    myapp-pbttb   1/1   Running   0     60s
    [root@master mainfests]# kubectl get pods
    NAME                            READY   STATUS    RESTARTS   AGE
    client                          0/1     Error     0          23h
    myapp-4tkhm                     1/1     Running   0          5m50s
    myapp-65899575cd-6p6qk          1/1     Running   1          22h
    myapp-dh45q                     1/1     Running   0          94s
    myapp-g6tgq                     1/1     Running   0          94s
    myapp-k5xtm                     1/1     Running   0          94s
    myapp-mmjjx                     1/1     Running   0          9m11s
    myapp-mpb79                     1/1     Running   0          94s
    myapp-pbttb                     1/1     Running   0          94s
    myapp-qnmnb                     1/1     Running   0          94s
    myapp-r4ldv                     1/1     Running   0          94s
    myapp-zmzhn                     1/1     Running   0          94s
    nginx-deploy-84cbfc56b6-h5h7x   1/1     Running   1          23h
    
    将myapp版本升级到v2
    [root@master mainfests]# kubectl edit rs myapp
    spec:
      replicas: 10
      selector:
        matchLabels:
          app: myapp
          release: canary
      template:
        metadata:
          creationTimestamp: null
          labels:
            app: myapp
            environment: qa
            release: canary
          name: myapp-pod
        spec:
          containers:
          - image: ikubernetes/myapp:v2
    [root@master mainfests]# kubectl get rs -o wide
    NAME                      DESIRED   CURRENT   READY   AGE   CONTAINERS        IMAGES                 SELECTOR
    myapp                     10        10        10      11m   myapp-container   
    [root@master mainfests]# kubectl get pods -o wide
    NAME                            READY   STATUS    RESTARTS   AGE     IP            NODE     NOMINATED NODE   READINESS GATES
    client                          0/1     Error     0          23h     <none>        node02   <none>           <none>
    myapp-4tkhm                     1/1     Running   0          8m21s   10.244.1.20   node01   <none>           <none>
    myapp-65899575cd-6p6qk          1/1     Running   1          22h     10.244.1.16   node01   <none>           <none>
    myapp-dh45q                     1/1     Running   0          4m5s    10.244.2.21   node02   <none>           <none>
    myapp-g6tgq                     1/1     Running   0          4m5s    10.244.2.23   node02   <none>           <none>
    myapp-k5xtm                     1/1     Running   0          4m5s    10.244.2.20   node02   <none>           <none>
    myapp-mmjjx                     1/1     Running   0          11m     10.244.2.19   node02   <none>           <none>
    myapp-mpb79                     1/1     Running   0          4m5s    10.244.2.22   node02   <none>           <none>
    myapp-pbttb                     1/1     Running   0          4m5s    10.244.1.23   node01   <none>           <none>
    myapp-qnmnb                     1/1     Running   0          4m5s    10.244.1.22   node01   <none>           <none>
    myapp-r4ldv                     1/1     Running   0          4m5s    10.244.1.24   node01   <none>           <none>
    myapp-zmzhn                     1/1     Running   0          4m5s    10.244.1.21   node01   <none>           <none>
    nginx-deploy-84cbfc56b6-h5h7x   1/1     Running   1          23h     10.244.2.15   node02   <none>           <none>
    
    这里myapp的镜像已经是v2版了，但是我们访问还是v1
    [root@master mainfests]# curl  10.244.1.22/hostname.html
    myapp-qnmnb
    [root@master mainfests]# curl  10.244.1.22
    Hello MyApp | Version: v1 | <a href="hostname.html">Pod Name</a>
    [root@master mainfests]# kubectl delete pods myapp-qnmnb
    pod "myapp-qnmnb" deleted
    [root@master mainfests]# kubectl get pods -o wide
    NAME                            READY   STATUS    RESTARTS   AGE     IP            NODE     NOMINATED NODE   READINESS GATES
    client                          0/1     Error     0          23h     <none>        node02   <none>           <none>
    myapp-27x5t                     1/1     Running   0          24s     10.244.1.25   node01   <none>           <none>
    myapp-4tkhm                     1/1     Running   0          10m     10.244.1.20   node01   <none>           <none>
    myapp-65899575cd-6p6qk          1/1     Running   1          22h     10.244.1.16   node01   <none>           <none>
    myapp-dh45q                     1/1     Running   0          5m50s   10.244.2.21   node02   <none>           <none>
    myapp-g6tgq                     1/1     Running   0          5m50s   10.244.2.23   node02   <none>           <none>
    myapp-k5xtm                     1/1     Running   0          5m50s   10.244.2.20   node02   <none>           <none>
    myapp-mmjjx                     1/1     Running   0          13m     10.244.2.19   node02   <none>           <none>
    myapp-mpb79                     1/1     Running   0          5m50s   10.244.2.22   node02   <none>           <none>
    myapp-pbttb                     1/1     Running   0          5m50s   10.244.1.23   node01   <none>           <none>
    myapp-r4ldv                     1/1     Running   0          5m50s   10.244.1.24   node01   <none>           <none>
    myapp-zmzhn                     1/1     Running   0          5m50s   10.244.1.21   node01   <none>           <none>
    nginx-deploy-84cbfc56b6-h5h7x   1/1     Running   1          23h     10.244.2.15   node02   <none>           <none>
    
    [root@master mainfests]# curl 10.244.1.25
    Hello MyApp | Version: v2 | <a href="hostname.html">Pod Name</a>
    [root@master mainfests]#

**注：也就是我们只有在删除容器时候在创建的时候才是v2版本，如果不删除还是v1版本，这样适合做蓝绿发布，可以做滚动式更新，也可控制更新节奏**

**注：上述更新镜像和扩容都可以在原配置文件进行修改**

**注：上述配置文件可以用****kubectl explain** **ReplicaSet**

[root@master mainfests]# kubectl explain ReplicaSet
    KIND:     ReplicaSet
    VERSION:  extensions/v1beta1
    
    DESCRIPTION:
         DEPRECATED - This group version of ReplicaSet is deprecated by
         apps/v1beta2/ReplicaSet. See the release notes for more information.
         ReplicaSet ensures that a specified number of pod replicas are running at
         any given time.
    
    FIELDS:
       apiVersion	<string>
         APIVersion defines the versioned schema of this representation of an
         object. Servers should convert recognized schemas to the latest internal
         value, and may reject unrecognized values. More info:
         https://git.k8s.io/community/contributors/devel/api-conventions.md#resources
    
       kind	<string>
         Kind is a string value representing the REST resource this object
         represents. Servers may infer this from the endpoint the client submits
         requests to. Cannot be updated. In CamelCase. More info:
         https://git.k8s.io/community/contributors/devel/api-conventions.md#types-kinds
    
       metadata	<Object>
         If the Labels of a ReplicaSet are empty, they are defaulted to be the same
         as the Pod(s) that the ReplicaSet manages. Standard object's metadata. More
         info:
         https://git.k8s.io/community/contributors/devel/api-conventions.md#metadata
    
       spec	<Object>
         Spec defines the specification of the desired behavior of the ReplicaSet.
         More info:
         https://git.k8s.io/community/contributors/devel/api-conventions.md#spec-and-status
    
       status	<Object>
         Status is the most recently observed status of the ReplicaSet. This data
         may be out of date by some window of time. Populated by the system.
         Read-only. More info:
         https://git.k8s.io/community/contributors/devel/api-conventions.md#spec-and-status

##  **演示Deployment在更新中显现出的强大功能** ##

[root@master mainfests]# vim rs-demo.yaml 
    [root@master mainfests]# cat rs-demo.yaml 
    apiVersion: apps/v1
    kind: Deployment
    metadata:
      name: myapp-deploy
      namespace: default
    spec:
      replicas: 2
      selector:
        matchLabels:
          app: myapp
          release: canary
      template:
        metadata:
          name: myapp-pod
          labels:
            app: myapp
            release: canary
        spec:
          containers:
          - name: myapp
            image: ikubernetes/myapp:v1
            ports:
            - name: http
              containerPort: 80
    [root@master mainfests]# kubectl apply -f rs-demo.yaml 
    deployment.apps/myapp-deploy created
    [root@master mainfests]# kubectl get pods
    NAME                            READY   STATUS    RESTARTS   AGE
    myapp-65899575cd-6p6qk          1/1     Running   1          22h
    myapp-deploy-848fb7b5b6-9tvns   1/1     Running   0          43s
    myapp-deploy-848fb7b5b6-mx2bp   1/1     Running   0          43s
    nginx-deploy-84cbfc56b6-h5h7x   1/1     Running   1          23h
    [root@master mainfests]# kubectl get deploy
    NAME           READY   UP-TO-DATE   AVAILABLE   AGE
    myapp          1/1     1            1           23h
    myapp-deploy   2/2     2            2           61s
    nginx-deploy   1/1     1            1           24h
    [root@master mainfests]# kubectl get rs
    NAME                      DESIRED   CURRENT   READY   AGE
    myapp-65899575cd          1         1         1       23h
    myapp-deploy-848fb7b5b6   2         2         2       70s
    nginx-deploy-84cbfc56b6   1         1         1       24h
    
    如果想更新的话，直接编辑deploy-demo.yaml文件即可
    
    [root@master mainfests]# !vim
    vim rs-demo.yaml   
    #  replicas: 4
    [root@master mainfests]# kubectl apply -f rs-demo.yaml 
    deployment.apps/myapp-deploy configured
    [root@master mainfests]# kubectl get rs
    NAME                      DESIRED   CURRENT   READY   AGE
    myapp-65899575cd          1         1         1       23h
    myapp-deploy-848fb7b5b6   4         4         4       4m28s
    nginx-deploy-84cbfc56b6   1         1         1       24h
    [root@master mainfests]# kubectl get pods
    NAME                            READY   STATUS    RESTARTS   AGE
    myapp-65899575cd-6p6qk          1/1     Running   1          23h
    myapp-deploy-848fb7b5b6-9tvns   1/1     Running   0          4m34s
    myapp-deploy-848fb7b5b6-l8cfj   1/1     Running   0          13s
    myapp-deploy-848fb7b5b6-mx2bp   1/1     Running   0          4m34s
    myapp-deploy-848fb7b5b6-qpfxp   1/1     Running   0          13s
    nginx-deploy-84cbfc56b6-h5h7x   1/1     Running   1          23h
    
    
    运行的容器更新版本：
    [root@master mainfests]# vim rs-demo.yaml 
    image: ikubernetes/myapp:v2
    [root@master mainfests]# kubectl apply -f rs-demo.yaml 
    deployment.apps/myapp-deploy configured
    [root@master mainfests]# kubectl get rs
    NAME                      DESIRED   CURRENT   READY   AGE
    myapp-65899575cd          1         1         1       23h
    myapp-9b4987d5            0         0         0       23h
    myapp-deploy-848fb7b5b6   0         0         0       6m19s
    myapp-deploy-fc7fc68b9    4         4         4       6s
    nginx-deploy-84cbfc56b6   1         1         1       24h
    
    
    查看历史的滚动记录
    [root@master mainfests]# kubectl rollout history deployment myapp-deploy
    deployment.extensions/myapp-deploy 
    REVISION  CHANGE-CAUSE
    0         <none>
    1         <none>
    2         <none>
    
    如果想返回上面的一个版本：
    [root@master mainfests]# kubectl rollout undo deployment myapp-deploy
    deployment.extensions/myapp-deploy rolled back
    [root@master mainfests]# kubectl get rs -o wide
    NAME                      DESIRED   CURRENT   READY   AGE     CONTAINERS        IMAGES                 SELECTOR
    myapp                     0         0         0       41m     myapp-container   ikubernetes/myapp:v2   app=myapp,release=canary
    myapp-65899575cd          1         1         1       23h     myapp             ikubernetes/myapp:v2   pod-template-hash=65899575cd,run=myapp
    myapp-9b4987d5            0         0         0       23h     myapp             ikubernetes/myapp:v1   pod-template-hash=9b4987d5,run=myapp
    myapp-deploy-848fb7b5b6   4         4         4       8m18s   myapp             ikubernetes/myapp:v1   app=myapp,pod-template-hash=848fb7b5b6,release=canary
    myapp-deploy-fc7fc68b9    0         0         0       2m5s    myapp             ikubernetes/myapp:v2   app=myapp,pod-template-hash=fc7fc68b9,release=canary
    nginx-deploy-84cbfc56b6   1         1         1       24h     nginx-deploy      nginx:1.14-alpine      pod-template-hash=84cbfc56b6,run=nginx-deplo
    [root@master mainfests]# kubectl rollout history deployment myapp-deploy
    deployment.extensions/myapp-deploy 
    REVISION  CHANGE-CAUSE
    0         <none>
    2         <none>
    3         <none>

**注： apply声明式创建，也可以创建，也可以更新**

**kubernetes应用中的灵活更新**

先启动一个监控窗口：
    kubectl get pods -l app=myapp -w
     
    再启动一个执行更新的窗口：
    [root@master test]# kubectl set image deployment myapp-deploy myapp=ikubernetes/myapp:v3 && kubectl rollout pause deployment myapp-deploy
     
    deployment.extensions/myapp-deploy image updated
    deployment.extensions/myapp-deploy paused
     
    监控端：显示现在镜像，创建容器 
     
    也可以使用这个命令来查看更新：
    [root@master ~]# kubectl rollout status deployment myapp-deploy
    Waiting for deployment "myapp-deploy" rollout to finish: 2 out of 4 new replicas have been updated...
     
    系统没有继续更新：执行下面的继续更新
    [root@master mainfests]# kubectl rollout resume deployment myapp-deploy
    deployment.extensions/myapp-deploy resumed
    
     
    [root@master ~]# kubectl rollout status deployment myapp-deploy
    Waiting for deployment "myapp-deploy" rollout to finish: 2 out of 4 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-deploy" rollout to finish: 2 out of 4 new replicas have been updated...
    Waiting for deployment "myapp-deploy" rollout to finish: 3 old replicas are pending termination...
    Waiting for deployment "myapp-deploy" rollout to finish: 1 old replicas are pending termination...
    Waiting for deployment "myapp-deploy" rollout to finish: 1 old replicas are pending termination...
    Waiting for deployment "myapp-deploy" rollout to finish: 1 old replicas are pending termination...
    Waiting for deployment "myapp-deploy" rollout to finish: 3 of 4 updated replicas are available...
    deployment "myapp-deploy" successfully rolled out
    
    查看历史版本：
    [root@master mainfests]# kubectl get rs -o wide
    NAME                      DESIRED   CURRENT   READY   AGE   CONTAINERS        IMAGES                 SELECTOR
    myapp-65899575cd          1         1         1       23h   myapp             ikubernetes/myapp:v2   pod-template-hash=65899575cd,run=myapp
    myapp-9b4987d5            0         0         0       23h   myapp             ikubernetes/myapp:v1   pod-template-hash=9b4987d5,run=myapp
    myapp-deploy-65df9c8bf6   4         4         4       18m   myapp             ikubernetes/myapp:v3   app=myapp,pod-template-hash=65df9c8bf6,release=canary
    myapp-deploy-848fb7b5b6   0         0         0       32m   myapp             ikubernetes/myapp:v1   app=myapp,pod-template-hash=848fb7b5b6,release=canary
    myapp-deploy-fc7fc68b9    0         0         0       25m   myapp             ikubernetes/myapp:v2   app=myapp,pod-template-hash=fc7fc68b9,release=canary
    nginx-deploy-84cbfc56b6   1         1         1       24h   nginx-deploy      nginx:1.14-alpine      pod-template-hash=84cbfc56b6,run=nginx-deploy
    
    
    通过上面发现，系统的版本都更新到了v3版，原来的版本已经暂停了
    日志上显示，下载镜像，删除一个，创建一个，可以控制节奏
    
    回滚历史版本：
    
    [root@master mainfests]# kubectl rollout history deployment myapp-deploy
    deployment.extensions/myapp-deploy 
    REVISION  CHANGE-CAUSE
    0         <none>
    2         <none>
    3         <none>
    4         <none>
    
    [root@master mainfests]# kubectl rollout undo deployment myapp-deploy --to-revision=2
    deployment.extensions/myapp-deploy rolled back
    [root@master mainfests]# kubectl get rs -o wide
    NAME                      DESIRED   CURRENT   READY   AGE   CONTAINERS        IMAGES                 SELECTOR
    myapp                     0         0         0       66m   myapp-container   ikubernetes/myapp:v2   app=myapp,release=canary
    myapp-65899575cd          1         1         1       23h   myapp             ikubernetes/myapp:v2   pod-template-hash=65899575cd,run=myapp
    myapp-9b4987d5            0         0         0       23h   myapp             ikubernetes/myapp:v1   pod-template-hash=9b4987d5,run=myapp
    myapp-deploy-65df9c8bf6   0         0         0       19m   myapp             ikubernetes/myapp:v3   app=myapp,pod-template-hash=65df9c8bf6,release=canary
    myapp-deploy-848fb7b5b6   0         0         0       33m   myapp             ikubernetes/myapp:v1   app=myapp,pod-template-hash=848fb7b5b6,release=canary
    myapp-deploy-fc7fc68b9    4         4         4       27m   myapp             ikubernetes/myapp:v2   app=myapp,pod-template-hash=fc7fc68b9,release=canary
    nginx-deploy-84cbfc56b6   1         1         1       24h   nginx-deploy      nginx:1.14-alpine      pod-template-hash=84cbfc56b6,run=nginx-deploy
    [root@master mainfests]# 
    [root@master mainfests]# kubectl rollout history deployment myapp-deploy
    deployment.extensions/myapp-deploy 
    REVISION  CHANGE-CAUSE
    0         <none>
    3         <none>
    4         <none>
    5         <none>

**注：上述其实实质是金丝雀发布**

## 部署redis项目 ##

[root@master mainfests]# vim redis_1.yaml
    [root@master mainfests]# cat redis_1.yaml 
    apiVersion: apps/v1
    kind: Deployment
    metadata:
      name: redis
      namespace: default
    spec:
      replicas: 1
      selector:
        matchLabels:
          app: redis
          role: logstor
      template:
        metadata:
          labels:
            app: redis
            role: logstor
        spec:
          containers:
          - name: redis
            image: redis:4.0-alpine
            ports:
            - name: redis
              containerPort: 6379
    
    ---
    apiVersion: apps/v1
    kind: DaemonSet
    metadata:
      name: filb-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@master mainfests]# kubectl create -f redis_1.yaml 
    deployment.apps/redis created
    daemonset.apps/filb-ds created
    [root@master mainfests]# kubectl get pods -w
    NAME                            READY   STATUS              RESTARTS   AGE
    client                          0/1     Error               0          24h
    filb-ds-qffsb                   0/1     ContainerCreating   0          49s
    filb-ds-r4kjg                   0/1     ContainerCreating   0          49s
    myapp-65899575cd-6p6qk          1/1     Running             1          23h
    myapp-deploy-fc7fc68b9-2gs52    1/1     Running             0          24m
    myapp-deploy-fc7fc68b9-6pbws    1/1     Running             0          24m
    myapp-deploy-fc7fc68b9-bjgk4    1/1     Running             0          24m
    myapp-deploy-fc7fc68b9-g22fs    1/1     Running             0          24m
    nginx-deploy-84cbfc56b6-h5h7x   1/1     Running             1          24h
    redis-85b846ff9c-rrvm5          0/1     ContainerCreating   0          49s
    redis-85b846ff9c-rrvm5   1/1   Running   0     2m52s
    filb-ds-r4kjg   1/1   Running   0     3m31s
    
    [root@master mainfests]# kubectl expose deployment redis --port=6379
    service/redis exposed
    [root@master mainfests]# kubectl get svc
    NAME         TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)        AGE
    kubernetes   ClusterIP   10.96.0.1       <none>        443/TCP        3d23h
    myapp        NodePort    10.108.224.2    <none>        80:31318/TCP   24h
    nginx        ClusterIP   10.107.43.244   <none>        80/TCP         24h
    redis        ClusterIP   10.99.139.119   <none>        6379/TCP       35s
    [root@master mainfests]# kubectl get pods
    NAME                            READY   STATUS    RESTARTS   AGE
    filb-ds-qffsb                   1/1     Running   0          14m
    filb-ds-r4kjg                   1/1     Running   0          14m
    myapp-65899575cd-6p6qk          1/1     Running   1          24h
    myapp-deploy-fc7fc68b9-2gs52    1/1     Running   0          38m
    myapp-deploy-fc7fc68b9-6pbws    1/1     Running   0          38m
    myapp-deploy-fc7fc68b9-bjgk4    1/1     Running   0          38m
    myapp-deploy-fc7fc68b9-g22fs    1/1     Running   0          38m
    nginx-deploy-84cbfc56b6-h5h7x   1/1     Running   1          24h
    redis-85b846ff9c-rrvm5          1/1     Running   0          14m
    [root@master mainfests]# kubectl exec -it redis-85b846ff9c-rrvm5 -- /bin/sh
    /data # netstat -tnl
    Active Internet connections (only servers)
    Proto Recv-Q Send-Q Local Address           Foreign Address         State       
    tcp        0      0 0.0.0.0:6379            0.0.0.0:*               LISTEN      
    tcp        0      0 :::6379                 :::*                    LISTEN      
    /data #  nslookup redis.default.svc.cluster.local
    nslookup: can't resolve '(null)': Name does not resolve
    
    Name:      redis.default.svc.cluster.local
    Address 1: 10.99.139.119 redis.default.svc.cluster.local
    /data # redis-cli -h redis.default.svc.cluster.local
    redis.default.svc.cluster.local:6379> KEYS *
    (empty list or set)
    [root@master mainfests]# kubectl exec -it filb-ds-qffsb -- /bin/sh
    / # ps aux
    PID   USER     TIME   COMMAND
        1 root       0:00 /usr/local/bin/filebeat -e -c /etc/filebeat/filebeat.yml
       11 root       0:00 /bin/sh
       16 root       0:00 ps aux
    / # printenv
    KUBERNETES_PORT=tcp://10.96.0.1:443
    KUBERNETES_SERVICE_PORT=443
    HOSTNAME=filb-ds-qffsb
    SHLVL=1
    HOME=/root
    NGINX_PORT_80_TCP=tcp://10.107.43.244:80
    MYAPP_SERVICE_HOST=10.108.224.2
    MYAPP_PORT=tcp://10.108.224.2:80
    MYAPP_SERVICE_PORT=80
    TERM=xterm
    KUBERNETES_PORT_443_TCP_ADDR=10.96.0.1
    MYAPP_PORT_80_TCP_ADDR=10.108.224.2
    NGINX_SERVICE_HOST=10.107.43.244
    PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
    KUBERNETES_PORT_443_TCP_PORT=443
    REDIS_LOG_LEVEL=info
    KUBERNETES_PORT_443_TCP_PROTO=tcp
    MYAPP_PORT_80_TCP_PORT=80
    MYAPP_PORT_80_TCP_PROTO=tcp
    NGINX_SERVICE_PORT=80
    NGINX_PORT=tcp://10.107.43.244:80
    KUBERNETES_SERVICE_PORT_HTTPS=443
    KUBERNETES_PORT_443_TCP=tcp://10.96.0.1:443
    PWD=/
    MYAPP_PORT_80_TCP=tcp://10.108.224.2:80
    KUBERNETES_SERVICE_HOST=10.96.0.1
    REDIS_HOST=redis.default.svc.cluster.local
    NGINX_PORT_80_TCP_ADDR=10.107.43.244
    FILEBEAT_VERSION=5.6.5
    NGINX_PORT_80_TCP_PORT=80
    NGINX_PORT_80_TCP_PROTO=tcp
    / # nslookup redis.default.svc.cluster.local
    nslookup: can't resolve '(null)': Name does not resolve
    
    nslookup: can't resolve 'redis.default.svc.cluster.local': Name does not resolve
    / # exit
    command terminated with exit code 1
    [root@master mainfests]#  kubectl get pods -l app=filebeat -o wide
    NAME            READY   STATUS    RESTARTS   AGE   IP            NODE     NOMINATED NODE   READINESS GATES
    filb-ds-qffsb   1/1     Running   0          12m   10.244.1.37   node01   <none>           <none>
    filb-ds-r4kjg   1/1     Running   0          12m   10.244.2.34   node02   <none>           <none>
    [root@master mainfests]# kubectl get ds
    NAME      DESIRED   CURRENT   READY   UP-TO-DATE   AVAILABLE   NODE SELECTOR   AGE
    filb-ds   2         2         2       2            2           <none>          13m