k8s deployment控制器的介绍

1. deployment 控制器的介绍

• Deployment的功能：

  • 管理Pod和ReplicaSet

  • 具有上线部署、副本设定、滚动升级、回滚等功能

  • 提供声明式更新，例如只更新一个新的Image

• 应用场景：网站、API、微服务

2. deployment 使用流程

​ 项目生命周期

3. deployment部署

• 部署

• 示例yaml配置

  apiVersion: apps/v1
  kind: Deployment
  metadata:
    name: web
    namespace: default
  spec:
    replicas: 3 # Pod副本预期数量
    selector:
      matchLabels:
        app: web
    template:
      metadata:
        labels:
          app: web # Pod副本的标签
      spec:
        containers:
        - name: web
          image: nginx:1.16
  

4. 案例

4.1 编写deployment的web.yaml文件

[root@k8s-master deployment]# vim web.yaml
[root@k8s-master deployment]# cat web.yaml 
apiVersion: apps/v1
kind: Deployment
metadata:
  name: web
  namespace: default
spec:
  replicas: 3 # Pod副本预期数量
  selector:
    matchLabels:
      app: web
  template:
    metadata:
      labels:
        app: web # Pod副本的标签
    spec:
      containers:
      - name: web
        image: nginx:1.16

4.2 启动服务

[root@k8s-master deployment]# kubectl apply -f web.yaml 
deployment.apps/web created

4.3 查看服务

[root@k8s-master deployment]# kubectl get pods
NAME                   READY   STATUS    RESTARTS   AGE
web-548b65b8c6-4k8n7   1/1     Running   0          2m24s
web-548b65b8c6-7wvhj   1/1     Running   0          2m24s
web-548b65b8c6-vpmpg   1/1     Running   0          2m24s
[root@k8s-master deployment]# kubectl get pods -o wide
NAME                   READY   STATUS    RESTARTS   AGE     IP               NODE        NOMINATED NODE   READINESS GATES
web-548b65b8c6-4k8n7   1/1     Running   0          2m56s   10.244.36.96     k8s-node1   <none>           <none>
web-548b65b8c6-7wvhj   1/1     Running   0          2m56s   10.244.169.159   k8s-node2   <none>           <none>
web-548b65b8c6-vpmpg   1/1     Running   0          2m56s   10.244.36.95     k8s-node1   <none>           <none>

4.4 deployment端口暴露

[root@k8s-master deployment]# kubectl expose deployment web --port=80 --target-port=80 --type=NodePort
service/web exposed

4.5 查询服务是否端口暴露

[root@k8s-master deployment]# kubectl get service 
NAME         TYPE        CLUSTER-IP       EXTERNAL-IP   PORT(S)        AGE
kubernetes   ClusterIP   10.96.0.1        <none>        443/TCP        6d
probe-demo   ClusterIP   10.104.161.168   <none>        80/TCP         2d
web          NodePort    10.98.32.199     <none>        80:30082/TCP   14s

4.6 浏览器测试