k8s使用Deployment实现应用系统不间断的自动更新

1、两个应用系统的版本，从V1升级到V2,已经打包在两个DOCKER镜像里面并上传到私有仓库

deployment如下：

[[email protected] upsystem]# cat war.yml 
apiVersion: apps/v1
kind: Deployment
metadata:
  name: tomcatwars
spec:
  selector:
    matchLabels:
      app: tomcatwar 
  replicas: 2
  template:
    metadata:
      labels:
        app: tomcatwar
    spec:
      imagePullSecrets:
      - name: registry-key
      containers:
      - name: tomcatwar
        image: re.bcdgptv.com.cn/war:v1
        ports: 
        - containerPort: 8080

 

service如下：

[[email protected] upsystem]# cat warservice.yml 
kind: Service
apiVersion: v1
metadata: 
  name: warservice
  labels:
    app: tomcatwar
spec:
  type: NodePort
  ports:
    - port: 8080
      protocol: TCP
      nodePort: 8899
  selector:
    app: tomcatwar
 

2、构建deployment，再发布服务

[[email protected] upsystem]# kubectl create -f war.yml

 

[[email protected] upsystem]# kubectl create -f warservice.yml 
service "warservice" created
[[email protected] upsystem]# kubectl get all
NAME                              READY     STATUS    RESTARTS   AGE
pod/tomcatwars-5d779647bb-9l5vd   1/1       Running   0          37m
pod/tomcatwars-5d779647bb-dqf5d   0/1       Evicted   0          37m
pod/tomcatwars-5d779647bb-pdg8l   1/1       Running   5          32m

NAME                 TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)         AGE
service/kubernetes   ClusterIP   10.254.0.1      <none>        443/TCP         43d
service/warservice   NodePort    10.254.101.86   <none>        8080:8899/TCP   1m

NAME                         DESIRED   CURRENT   UP-TO-DATE   AVAILABLE   AGE
deployment.apps/tomcatwars   2         2         2            2           37m

NAME                                    DESIRED   CURRENT   READY     AGE
replicaset.apps/tomcatwars-5d779647bb   2         2         2         37m

此时访问应用：

 

3、发布新的镜像包

将配置文件的V1改成V2,已经将V2上传到私有仓库

[[email protected] upsystem]# cat war.yml 
apiVersion: apps/v1
kind: Deployment
metadata:
  name: tomcatwars
spec:
  selector:
    matchLabels:
      app: tomcatwar 
  replicas: 2
  template:
    metadata:
      labels:
        app: tomcatwar
    spec:
      imagePullSecrets:
      - name: registry-key
      containers:
      - name: tomcatwar
        image: re.bcdgptv.com.cn/war:v2
        ports: 
        - containerPort: 8080

 

应用配置文件

[[email protected] upsystem]# kubectl apply -f war.yml 
Warning: kubectl apply should be used on resource created by either kubectl create --save-config or kubectl apply
deployment.apps "tomcatwars" configured

[[email protected] upsystem]# kubectl get all
NAME                              READY     STATUS         RESTARTS   AGE
pod/tomcatwars-5d779647bb-9l5vd   1/1       Running        0          1h
pod/tomcatwars-5d779647bb-dqf5d   0/1       Evicted        0          1h
pod/tomcatwars-5d779647bb-pdg8l   1/1       Running        5          1h
pod/tomcatwars-795c6cf95f-v7kdx   0/1       ErrImagePull   0          2m
pod/tomcatwars-795c6cf95f-z5cpl   0/1       Evicted        0          9m

NAME                 TYPE        CLUSTER-IP       EXTERNAL-IP   PORT(S)         AGE
service/kubernetes   ClusterIP   10.254.0.1       <none>        443/TCP         43d
service/warservice   NodePort    10.254.159.193   <none>        8080:8899/TCP   23m

NAME                         DESIRED   CURRENT   UP-TO-DATE   AVAILABLE   AGE
deployment.apps/tomcatwars   2         3         1            2           1h

NAME                                    DESIRED   CURRENT   READY     AGE
replicaset.apps/tomcatwars-5d779647bb   2         2         2         1h
replicaset.apps/tomcatwars-795c6cf95f   1         1         0         9m
[[email protected] upsystem]# kubectl get all
NAME                              READY     STATUS    RESTARTS   AGE
pod/tomcatwars-5d779647bb-dqf5d   0/1       Evicted   0          1h
pod/tomcatwars-795c6cf95f-6kn9w   1/1       Running   0          7m
pod/tomcatwars-795c6cf95f-v7kdx   1/1       Running   0          13m
pod/tomcatwars-795c6cf95f-z5cpl   0/1       Evicted   0          20m

NAME                 TYPE        CLUSTER-IP       EXTERNAL-IP   PORT(S)         AGE
service/kubernetes   ClusterIP   10.254.0.1       <none>        443/TCP         43d
service/warservice   NodePort    10.254.159.193   <none>        8080:8899/TCP   34m

NAME                         DESIRED   CURRENT   UP-TO-DATE   AVAILABLE   AGE
deployment.apps/tomcatwars   2         2         2            2           1h

NAME                                    DESIRED   CURRENT   READY     AGE
replicaset.apps/tomcatwars-5d779647bb   0         0         0         1h
replicaset.apps/tomcatwars-795c6cf95f   2         2         2         20m

 

等POD更新完成以后，应用发布完成，更新过程中，应用访问不中断