docker中pod控制器怎么用

这篇文章给大家分享的是有关docker中pod控制器怎么用的内容。小编觉得挺实用的，因此分享给大家做个参考，一起跟随小编过来看看吧。

之前创建的pod，是通过资源配置清单定义的，如果手工把这样的pod删除后，不会自己重新创建，这样创建的pod叫自主式Pod。

在生产中，我们很少使用自主式pod。

下面我们学习另外一种pod，叫控制器管理的Pod，控制器会按照定义的策略严格控制pod的数量，一旦发现pod数量少了，会立即自动建立出来新的pod；一旦发现pod多了，也会自动杀死多余的Pod。

pod控制器：ReplicaSet控制器、Deployment控制器（必须掌握）、DaenibSet控制器、Job控制器

ReplicaSet控制器：替用户创建指定数量Pod的副本，并保证pod副本满足用户期望的数量；而且更新自动扩缩容机制。replicat主要由三个组件组成：1、用户期望的pod副本数量；2、标签选择器（控制管理pod副本）；3、pod资源模板（如果pod数量少于期望的，就根据pod模板来新建一定数量的pod）。

Deployment控制器：Deployment通过控制replicaset来控制Pod。Deployment支持滚动更新和回滚，声明式配置的功能。Deployment只关注群体，而不关注个体。

DaemonSet控制器：用于确保集群中的每一个节点只运行一个pod副本（画外音，如果没有DaemonSet，一个节点可以运行多个pod副本）。如果在集群中新加一个节点，那么这个新节点也会自动生成一个Pod副本。

Job控制器：对于那些只做一次，只要完成就正常退出，没完成才重构pod ，叫job控制器。

StatefulSet控制器：管理有状态应用，每一个pod副本都是被单独管理的。它拥有着自己独有的标识。

K8s在1.2+和1.7开始，支持TPR(third party resources 第三方资源)。在k8s 1.8+中，支持CDR(Custom Defined Reources，用户自定义资源)。

replicaset控制器

[root@master manifests]# kubectl explain replicaset[root@master manifests]# kubectl explain  rs (replicaset的简写)[root@master manifests]# kubectl explain rs.spec.template

[root@master manifests]# kubectl get deployNAME           DESIRED   CURRENT   UP-TO-DATE   AVAILABLE   AGEmyapp          2         2         2            0           10dmytomcat       3         3         3            3           10dnginx-deploy   1         1         1            1           13d[root@master manifests]# kubectl delete deploy myapp deployment.extensions "myapp" deleted[root@master manifests]# kubectl delete deploy nginx-deploydeployment.extensions "nginx-deploy" deleted

[root@master manifests]# cat rs-demo.yaml apiVersion: apps/v1kind: ReplicaSetmetadata:  name: myapp  namespace: defaultspec: #这是控制器的spec  replicas: 2 #几个副本  selector:   #查看帮助:,标签选择器。 kubectl explain rs.spec.selector    matchLabels:      app: myapp      release: canary  template:  # 查看帮助：模板 kubectl explain rs.spec.template    metadata: # kubectl explain rs.spec.template.metadata      name: myapp-pod      labels:  #必须符合上面定义的标签选择器selector里面的内容        app: myapp        release: canary        environment: qa    spec: #这是pod的spec      containers:      - name: myapp-container        image: ikubernetes/nginx:latest        ports:         - name: http          containerPort: 80

[root@master manifests]# kubectl create -f rs-demo.yaml replicaset.apps/myapp created

[root@master manifests]# kubectl get rsNAME                 DESIRED   CURRENT   READY     AGEmyapp                2         2         2         3m

看到上面的ready是2，表示两个replcatset控制器都在正常运行。

[root@master manifests]# kubectl get pods --show-labelsmyapp-6kncv                1/1       Running            0          15m       app=myapp,environment=qa,release=canarymyapp-rbqjz                1/1       Running            0          15m       app=myapp,environment=qa,release=canary         5mpod-demo                   0/2       CrashLoopBackOff   2552       9d        app=myapp,tier=frontend

上面就是replicatset控制器创建的两个pod。

[root@master manifests]# kubectl describe pods myapp-6kncv IP:                 10.244.2.44

[root@master manifests]# curl  10.244.2.44Hello MyApp | Version: v1 | Pod Name

编辑replicatset的配置文件（这个文件不是我们手工创建的，而是apiserver维护的）

[root@master manifests]# kubectl edit rs myapp

把里面的replicas改成5，保存后就立即生效。

[root@master manifests]#  kubectl get pods --show-labelsNAME                       READY     STATUS              RESTARTS   AGE       LABELSclient                     0/1       Error               0          11d       run=clientliveness-httpget-pod       1/1       Running             3          5d        myapp-6kncv                1/1       Running             0          31m       app=myapp,environment=qa,release=canarymyapp-c64mb                1/1       Running             0          3s        app=myapp,environment=qa,release=canarymyapp-fsrsg                1/1       Running             0          3s        app=myapp,environment=qa,release=canarymyapp-ljczj                0/1       ContainerCreating   0          3s        app=myapp,environment=qa,release=canarymyapp-rbqjz                1/1       Running             0          31m       app=myapp,environment=qa,release=canary

同样，也可以用命令kubectl edit rs myapp升级版本，改里面的image: ikubernetes/myapp:v2，这样就变成v2版本了。

[root@master manifests]# kubectl get rs -o wideNAME                 DESIRED   CURRENT   READY     AGE       CONTAINERS        IMAGES                 SELECTORmyapp                5         5         5         1h        myapp-container   ikubernetes/myapp:v2   app=myapp,release=canary

不过，只有pod重建后，比如增加删除Pod，才会更新成v2版本。

Deployment控制器

我们可以通过Deployment控制器来动态更新pod的版本。

我们先建立replicatset v2版本，然后一个一个的删除replicatset v1版本中的Pod，这样自动新创建的pod就会变成v2版本了。当pod全部变成v2版本后，replicatset v1并不会删除，这样一旦发现v2版本有问题，还可以回退到v1版本。

通常deployment默认保留10版本的replicatset。

[root@master manifests]# kubectl explain deploy[root@master manifests]# kubectl explain deploy.spec[root@master manifests]# kubectl explain deploy.spec.strategy （更新策略）[root@master ~]# kubectl delete rs myapp

[root@master manifests]# cat deploy-demo.yamlapiVersion: apps/v1kind: Deploymentmetadata:  name: myapp-deploy  namespace: defaultspec:  replicas: 2  selector: #标签选择器    matchLabels: #匹配的标签为      app: myapp      release: canary  template:    metadata:      labels:        app: myapp #和上面的myapp要匹配        release: canary    spec:      containers:      - name: myapp        image: ikubernetes/myapp:v1        ports:        - name: http          containerPort: 80

[root@master manifests]# kubectl apply -f deploy-demo.yaml deployment.apps/myapp-deploy created

apply表示是声明式更新和创建。

[root@master manifests]# kubectl get deployNAME           DESIRED   CURRENT   UP-TO-DATE   AVAILABLE   AGEmyapp-deploy   2         2         2            2           1m

[root@master ~]# kubectl get rsNAME                      DESIRED   CURRENT   READY     AGEmyapp-deploy-69b47bc96d   2         2         2         17m

上面的rs式deployment自动创建的。

[root@master ~]# kubectl get podsNAME                            READY     STATUS    RESTARTS   AGEmyapp-deploy-69b47bc96d-7jnwx   1/1       Running   0          19mmyapp-deploy-69b47bc96d-btskk   1/1       Running   0          19m

修改配置文件deploy-demo.yaml，把replicas数字改成3，然后再执行kubectl apply -f deploy-demo.yaml 即可使配置文件里面的内容生效。

[root@master ~]# kubectl describe deploy myapp-deploy

[root@master ~]# kubectl get pods -l app=myapp -w

-l使标签过滤

-w是动态监控

[root@master ~]# kubectl get rs -o wideNAME                      DESIRED   CURRENT   READY     AGE       CONTAINERS   IMAGES                 SELECTORmyapp-deploy-69b47bc96d   2         2         2         1h        myapp        ikubernetes/myapp:v1   app=myapp,pod-template-hash=2560367528,release=canary

看滚动更新的历史：

[root@master ~]# kubectl rollout history deployment myapp-deploydeployments "myapp-deploy"REVISION  CHANGE-CAUSE1         

下面我们把deployment改成5个：我们可以使用vim deploy-demo.yaml方法，把里面的replicas改成5。当然，还可以使用另外一种方法，就patch方法，举例如下。

[root@master manifests]# kubectl patch deployment myapp-deploy -p '{"spec":{"replicas":5}}'deployment.extensions/myapp-deploy patched

[root@master manifests]#  kubectl get deployNAME           DESIRED   CURRENT   UP-TO-DATE   AVAILABLE   AGEmyapp-deploy   5         5         5            5           2h

[root@master manifests]#  kubectl get podsNAME                            READY     STATUS    RESTARTS   AGEmyapp-deploy-69b47bc96d-7jnwx   1/1       Running   0          2hmyapp-deploy-69b47bc96d-8gn7v   1/1       Running   0          59smyapp-deploy-69b47bc96d-btskk   1/1       Running   0          2hmyapp-deploy-69b47bc96d-p5hpd   1/1       Running   0          59smyapp-deploy-69b47bc96d-zjv4p   1/1       Running   0          59smytomcat-5f8c6fdcb-9krxn        1/1       Running   0          8h

下面修改策略：

[root@master manifests]# kubectl patch deployment myapp-deploy -p '{"spec":{"strategy":{"rollingUpdate":{"maxSurge":1,"maxUnavaliable":0}}}}'deployment.extensions/myapp-deploy patched

strategy：表示策略

maxSurge：表示最多几个控制器存在

maxUnavaliable：表示最多有几个控制器不可用

[root@master manifests]# kubectl describe deployment myapp-deployRollingUpdateStrategy: 0 max unavailable, 1 max surge

下面我们用set image命令，将镜像myapp升级为v3版本，并且将myapp-deploy控制器标记为暂停。被pause命令暂停的资源不会被控制器协调使用，可以使"kubectl rollout resume"命令恢复已暂停资源。

[root@master manifests]# kubectl set image deployment myapp-deploy myapp=ikubernetes/myapp:v3 &&kubectl rollout pause deployment myapp-deploy

[root@master ~]# kubectl get pods -l app=myapp -w

停止暂停：

[root@master ~]# kubectl rollout resume deployment myapp-deploydeployment.extensions/myapp-deploy resumed

看到继续更新了（即删一个更新一个，删一个更新一个）：

[root@master manifests]# kubectl rollout status deployment myapp-deployWaiting for deployment "myapp-deploy" rollout to finish: 2 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-deploy" rollout to finish: 2 out of 5 new replicas have been updated...Waiting for deployment "myapp-deploy" rollout to finish: 3 out of 5 new replicas have been updated...Waiting for deployment "myapp-deploy" rollout to finish: 3 out of 5 new replicas have been updated...Waiting for deployment "myapp-deploy" rollout to finish: 4 out of 5 new replicas have been updated...Waiting for deployment "myapp-deploy" rollout to finish: 4 out of 5 new replicas have been updated...Waiting for deployment "myapp-deploy" rollout to finish: 4 out of 5 new replicas have been updated...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...deployment "myapp-deploy" successfully rolled out

[root@master manifests]# kubectl get rs -o wideNAME                      DESIRED   CURRENT   READY     AGE       CONTAINERS   IMAGES                 SELECTORmyapp-deploy-69b47bc96d   0         0         0         6h        myapp        ikubernetes/myapp:v1   app=myapp,pod-template-hash=2560367528,release=canarymyapp-deploy-6bdcd6755d   5         5         5         3h        myapp        ikubernetes/myapp:v3   app=myapp,pod-template-hash=2687823118,release=canarymytomcat-5f8c6fdcb        3         3         3         12h       mytomcat     tomcat                 pod-template-hash=194729876,run=mytomcat

上面可以看到myapp有v1和v3两个版本。

[root@master manifests]# kubectl rollout history deployment myapp-deploydeployments "myapp-deploy"REVISION  CHANGE-CAUSE1         2         

上面可以看到有两个历史更新记录。

下面我们把v3回退到上一个版本（不指定就是上一个版本）。

[root@master manifests]# kubectl  rollout undo deployment myapp-deploy --to-revision=1deployment.extensions/myapp-deploy

可以看到第一版还原成第3版了：

[root@master manifests]# kubectl rollout history deployment myapp-deploydeployments "myapp-deploy"REVISION  CHANGE-CAUSE2         3         

可以看到正在工作的是v1版，即回退到了v1版。

[root@master manifests]# kubectl get rs -o wideNAME                      DESIRED   CURRENT   READY     AGE       CONTAINERS   IMAGES                 SELECTORmyapp-deploy-69b47bc96d   5         5         5         6h        myapp        ikubernetes/myapp:v1   app=myapp,pod-template-hash=2560367528,release=canarymyapp-deploy-6bdcd6755d   0         0         0         3h        myapp        ikubernetes/myapp:v3   app=myapp,pod-template-hash=2687823118,release=canary

DaemonSet控制器

通过 https://hub.docker.com/r/ikubernetes/filebeat/tags/可以看到filebeat的版本有哪些：

[root@node1 manifests]# docker pull ikubernetes/filebeat:5.6.5-alpine[root@node2 manifests]# docker pull ikubernetes/filebeat:5.6.5-alpine

node1和node2上都下载filebeat镜像。

[root@node1 ~]# docker image inspect ikubernetes/filebeat:5.6.5-alpine

[root@master manifests]# kubectl explain pods.spec.containers.env

[root@master manifests]# cat ds-demo.yaml apiVersion: apps/v1kind: DaemonSetmetadata:  name: myapp-ds  namespace: defaultspec:  selector: #标签选择器    matchLabels: #匹配的标签为      app: filebeat      release: stable  template:    metadata:      labels:        app: filebeat #和上面的myapp要匹配        release: stable    spec:      containers:      - name: myapp        image: ikubernetes/myapp:v1        env:        - name: REDIS_HOST          value: redis.default.svc.cluster.local #随便取的名字          name: REDIS_LOG_LEVEL          value: info

[root@master manifests]# kubectl apply -f ds-demo.yaml daemonset.apps/myapp-ds created

看到myapp-ds已经运行起来了，并且是两个myapp-ds，这是因为我们有两个Node节点。另外master节点上是不会运行myapp-ds控制器的，因为master有污点（除非你设置允许有污点，才可以在master上允许myapp-ds）

[root@master manifests]# kubectl get podsNAME                            READY     STATUS    RESTARTS   AGEmyapp-ds-5tmdd                  1/1       Running   0          1mmyapp-ds-dkmjj                  1/1       Running   0          1m

[root@master ~]# kubectl logs  myapp-ds-dkmjj

[root@master manifests]# kubectl delete -f ds-demo.yaml

[root@master manifests]# cat ds-demo.yaml apiVersion: apps/v1kind: Deploymentmetadata:  name: redis  namespace: defaultspec:  replicas: 1  selector:    matchLabels:      app: redis      role: logstor #日志存储角色  template:    metadata:      labels:        app: redis        role: logstor    spec: #这个是容器的spec      containers:      - name: redis        image: redis:4.0-alpine        ports:        - name: redis          containerPort: 6379#用减号隔离资源定义清单---apiVersion: apps/v1kind: DaemonSetmetadata:  name: filebeat-ds  namespace: defaultspec:  selector: #标签选择器    matchLabels: #匹配的标签为      app: filebeat      release: stable  template:    metadata:      labels:        app: filebeat #和上面的myapp要匹配        release: stable    spec:      containers:      - name: filebeat        image: ikubernetes/filebeat:5.6.6-alpine        env:        - name: REDIS_HOST #这是环境变量名,value是它的值          value: redis.default.svc.cluster.local #随便取的名字        - name: REDIS_LOG_LEVEL          value: info

[root@master manifests]# kubectl create -f ds-demo.yaml deployment.apps/redis createddaemonset.apps/filebeat-ds created

[root@master manifests]# kubectl expose deployment redis --port=6379 ##这是在用expose方式创建service，其实还有一种方式是根据清单创建serviceservice/redis exposed

[root@master manifests]# kubectl get svc  #service的简称NAME         TYPE        CLUSTER-IP       EXTERNAL-IP   PORT(S)        AGEredis        ClusterIP   10.106.138.181           6379/TCP       48s

[root@master manifests]# kubectl get podsNAME                            READY     STATUS    RESTARTS   AGEfilebeat-ds-hgbhr               1/1       Running   0          9hfilebeat-ds-xc7v7               1/1       Running   0          9hredis-5b5d6fbbbd-khws2          1/1       Running   0          33m

[root@master manifests]# kubectl exec -it redis-5b5d6fbbbd-khws2 -- /bin/sh/data # netstat -tnlActive 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  #看到DNS可以解析出来ipnslookup: can't resolve '(null)': Name does not resolveName:      redis.default.svc.cluster.localAddress 1: 10.106.138.181 redis.default.svc.cluster.local /data # redis-cli -h redis.default.svc.cluster.localredis.default.svc.cluster.local:6379> keys *(empty list or set)redis.default.svc.cluster.local:6379>

[root@master manifests]# kubectl exec -it filebeat-ds-pnk8b -- /bin/sh/ # ps auxPID   USER     TIME   COMMAND    1 root       0:00 /usr/local/bin/filebeat -e -c /etc/filebeat/filebeat.yml   15 root       0:00 /bin/sh   22 root       0:00 ps aux  / # cat  /etc/filebeat/filebeat.ymlfilebeat.registry_file: /var/log/containers/filebeat_registryfilebeat.idle_timeout: 5sfilebeat.spool_size: 2048logging.level: infofilebeat.prospectors:- input_type: log  paths:    - "/var/log/containers/*.log"    - "/var/log/docker/containers/*.log"    - "/var/log/startupscript.log"    - "/var/log/kubelet.log"    - "/var/log/kube-proxy.log"    - "/var/log/kube-apiserver.log"    - "/var/log/kube-controller-manager.log"    - "/var/log/kube-scheduler.log"    - "/var/log/rescheduler.log"    - "/var/log/glbc.log"    - "/var/log/cluster-autoscaler.log"  symlinks: true  json.message_key: log  json.keys_under_root: true  json.add_error_key: true  multiline.pattern: '^\s'  multiline.match: after  document_type: kube-logs  tail_files: true  fields_under_root: trueoutput.redis:  hosts: ${REDIS_HOST:?No Redis host configured. Use env var REDIS_HOST to set host.}  key: "filebeat"    / # printenvREDIS_HOST=redis.default.svc.cluster.local/ # nslookup redis.default.svc.cluster.localnslookup: can't resolve '(null)': Name does not resolveName:      redis.default.svc.cluster.localAddress 1: 10.106.138.181 redis.default.svc.cluster.local

daemon-set也支持滚动更新。

[root@master manifests]# kubectl set image daemonsets filebeat-ds filebeat=ikubernetes/filebeat:5.5.7-alpine

说明： daemonsets filebeat-ds表示daemonsets名字叫filebeat-ds；

filebeat=ikubernetes/filebeat:5.5.7-alpine表示filebeat容器=ikubernetes/filebeat:5.5.7-alpine

感谢各位的阅读！关于"docker中pod控制器怎么用"这篇文章就分享到这里了，希望以上内容可以对大家有一定的帮助，让大家可以学到更多知识，如果觉得文章不错，可以把它分享出去让更多的人看到吧！