【原文链接】

一、NodePort类型的Service简介

ClusterIP类型和Headless类型的Service都只能在集群环境内部访问，如果想开放给集群环境以外访问，那就需要使用NodePort类型，NodePort的工作原理其实就是将service的端口映射到Node的端口上，然后通过NodeIP:NodePort 来访问Service

二、环境准备

编写deployment.yaml文件，内容如下：

apiVersion: v1
kind: Namespace
metadata:
  name: dev

---

apiVersion: apps/v1
kind: Deployment
metadata:
  name: pc-deployment
  namespace: dev
spec:
  replicas: 3
  selector:
    matchLabels:
      app: nginx-pod
  template:
    metadata:
      labels:
        app: nginx-pod
    spec:
      containers:
      - name: nginx
        image: nginx:1.17.1
        ports:
        - containerPort: 80

然后使用如下命令创建资源

[root@master service]# kubectl apply -f deployment.yaml
namespace/dev created
deployment.apps/pc-deployment created
[root@master service]#

查看创建的资源如下：

[root@master service]# kubectl get deploy,pod -n dev -o wide
NAME                            READY   UP-TO-DATE   AVAILABLE   AGE   CONTAINERS   IMAGES         SELECTOR
deployment.apps/pc-deployment   3/3     3            3           17m   nginx        nginx:1.17.1   app=nginx-pod

NAME                                 READY   STATUS    RESTARTS   AGE   IP             NODE    NOMINATED NODE   READINESS GATES
pod/pc-deployment-5ffc5bf56c-mqwst   1/1     Running   0          17m   10.244.2.191   node2   <none>           <none>
pod/pc-deployment-5ffc5bf56c-qbznm   1/1     Running   0          17m   10.244.1.53    node1   <none>           <none>
pod/pc-deployment-5ffc5bf56c-zxnsx   1/1     Running   0          17m   10.244.2.190   node2   <none>           <none>
[root@master service]#

三、创建NodePort类型Service

编辑nodeport.yaml文件，内容如下：

apiVersion: v1
kind: Service
metadata:
  name: service-nodeport
  namespace: dev
spec:
  selector:
    app: nginx-pod
  type: NodePort
  ports:
  - port: 80
    nodePort: 30002
    targetPort: 80

使用如下命令创建服务

[root@master service]# kubectl apply -f nodeport.yaml
service/service-nodeport created
[root@master service]#

查看所创建的资源如下：

[root@master service]# kubectl get service,deployment,pod -n dev
NAME                       TYPE       CLUSTER-IP       EXTERNAL-IP   PORT(S)        AGE
service/service-nodeport   NodePort   10.107.215.143   <none>        80:30002/TCP   10m

NAME                            READY   UP-TO-DATE   AVAILABLE   AGE
deployment.apps/pc-deployment   3/3     3            3           23h

NAME                                 READY   STATUS    RESTARTS   AGE
pod/pc-deployment-5ffc5bf56c-mqwst   1/1     Running   0          23h
pod/pc-deployment-5ffc5bf56c-qbznm   1/1     Running   0          23h
pod/pc-deployment-5ffc5bf56c-zxnsx   1/1     Running   0          23h
[root@master service]#

此时可以在集群环境之外，通过节点ip：port访问服务，如这里节点ip为192.168.16.40，端口为30002，如下：