deployment

run 创建的是deployment， deployment简写可以写deploy。

deployment是pod的控制器，用来管理容器的。

查看kubectl run的帮助

kubectl run --help

创建一个指定多个参数的deployment

这里run后面的nginx-deploy是本次创建的deploy的名称。

–image=指定的是镜像名和版本，

nginx是镜像名，冒号:后面的是镜像版本。

–port是指定容器的打开端口。

–replicas=2 代表启动并保持2个pod。

下面的kubectl get 的状态里， Running表示pod已经在运行了。 ContainerCreating表示pod正在创建，一般是pod所分配到的node上还没有下载好镜像，正在下载镜像，等待一会在get查看就好了。

[root@k8s1 ~]# kubectl run nginx-deploy --image=nginx:1.14-alpine --port=80 --replicas=2
deployment.apps/nginx-deploy created
[root@k8s1 ~]#
[root@k8s1 ~]# kubectl get deployment
NAME           DESIRED   CURRENT   UP-TO-DATE   AVAILABLE   AGE
nginx-deploy   2         2         2            1           6s
[root@k8s1 ~]#
[root@k8s1 ~]# kubectl get pod
NAME                          READY     STATUS              RESTARTS   AGE
nginx-deploy-5b595999-cqwkd   0/1       ContainerCreating   0          9s
nginx-deploy-5b595999-f4m8x   1/1       Running             0          9s
[root@k8s1 ~]#
[root@k8s1 ~]# kubectl get pod -o wide
NAME                          READY     STATUS              RESTARTS   AGE       IP            NODE               NOMINATED NODE
nginx-deploy-5b595999-cqwkd   0/1       ContainerCreating   0          20s       <none>        k8s2.shenmin.com   <none>
nginx-deploy-5b595999-f4m8x   1/1       Running             0          20s       10.244.2.10   k8s3.shenmin.com   <none>

root@k8s1 ~]# kubectl get pod -o wide
NAME                          READY     STATUS    RESTARTS   AGE       IP            NODE               NOMINATED NODE
nginx-deploy-5b595999-cqwkd   1/1       Running   0          3m        10.244.1.9    k8s2.shenmin.com   <none>
nginx-deploy-5b595999-f4m8x   1/1       Running   0          3m        10.244.2.10   k8s3.shenmin.com   <none>

删除一个pod，验证其保持pod数量的功能

这里可以看到有两个pod，我们删除其中一个，然后再get查看，发现原有的那个pod已经被删除了，通过pod名称可以判断。然后又重新启动了一个pod。

[root@k8s1 ~]# kubectl get pod -o wide
NAME                          READY     STATUS    RESTARTS   AGE       IP            NODE               NOMINATED NODE
nginx-deploy-5b595999-cqwkd   1/1       Running   0          3m        10.244.1.9    k8s2.shenmin.com   <none>
nginx-deploy-5b595999-f4m8x   1/1       Running   0          3m        10.244.2.10   k8s3.shenmin.com   <none>
[root@k8s1 ~]#
[root@k8s1 ~]# kubectl delete pod nginx-deploy-5b595999-cqwkd
pod "nginx-deploy-5b595999-cqwkd" deleted

[root@k8s1 ~]#
[root@k8s1 ~]# kubectl get pod -o wide
NAME                          READY     STATUS    RESTARTS   AGE       IP            NODE               NOMINATED NODE
nginx-deploy-5b595999-94z9p   1/1       Running   0          14s       10.244.1.10   k8s2.shenmin.com   <none>
nginx-deploy-5b595999-f4m8x   1/1       Running   0          5m        10.244.2.10   k8s3.shenmin.com   <none>

通过yaml文件创建一个deployment

[alvin@k8s1 ~]$ vim registry.yaml
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name: registry
spec:
  replicas: 1
  template:
    metadata:
      labels:
        run: registry
    spec:
      containers:
      - name: registry
        resources:
          limits:
            cpu: 2
            memory: 200Mi
          requests:
            cpu: 0.5
            memory: 100Mi
        image: registry:2
        ports:
        - containerPort: 5000
          protocol: TCP
          name: registry-port
        volumeMounts:
        - name: registry-nfs-data
          mountPath: /var/lib/registry
          readOnly: false
        - name: registry-nfs-config
          mountPath:  /etc/docker/registry
          readOnly: true
      volumes:
      - name: registry-nfs-data
        nfs:
          server: 192.168.127.54
          path: '/registry/data'
      - name: registry-nfs-config
        nfs:
          server: 192.168.127.54
          path: '/registry/config'

$ kubectl create -f registry.yaml