k8s 启动service样例，端口访问分析

更多kubernetes文章： k8s专栏目录

port targetPort nodePort关系见文章：

http://blog.csdn.net/liyingke112/article/details/76022267

1.准备镜像 编辑配置文件，这里使用的是httpd做测试，默认开80端口

[root@tensorflow1 serviceTest]# cat httpd.yaml

# -------------------  Deployment ------------------- #

kind: Deployment

apiVersion: apps/v1beta2

metadata:

  labels:

    k8s-app: httpd

  name: httpd

spec:

  replicas: 1

  selector:

    matchLabels:

      k8s-app: httpd

  template:

    metadata:

      labels:

        k8s-app: httpd

    spec:

      containers:

      - name: httpd

        image: httpd

---

# ------------------- Service ------------------- #

kind: Service

apiVersion: v1

metadata:

  labels:

    k8s-app: httpd

  name: httpd

spec:

  type: NodePort

  ports:

    - port: 8081

      targetPort: 80

      nodePort: 30001

  selector:

    k8s-app: httpd

2.启动

[root@tensorflow1 serviceTest]# kubectl create -f httpd.yaml

3.查看启动情况

[root@tensorflow1 serviceTest]# kubectl get all -o wide --all-namespaces

NAMESPACE     NAME                                     READY     STATUS    RESTARTS   AGE       IP              NODE

default       po/httpd-68f9d7648d-tv9xv                1/1       Running   0          26m       10.244.1.10     tensorflow2

NAMESPACE     NAME             TYPE        CLUSTER-IP       EXTERNAL-IP   PORT(S)          AGE       SELECTOR

default       svc/httpd        NodePort    10.100.205.181           8081:30001/TCP   35m       k8s-app=httpd

[root@tensorflow1 serviceTest]# kubectl describe svc/httpd

Name:                     httpd

Namespace:                default

Labels:                   k8s-app=httpd

Annotations:              kubectl.kubernetes.io/last-applied-configuration={"apiVersion":"v1","kind":"Service","metadata":{"annotations":{},"labels":{"k8s-app":"httpd"},"name":"httpd","namespace":"default"},"spec":{"ports":[{"...

Selector:                 k8s-app=httpd

Type:                     NodePort

IP:                       10.100.205.181

Port:                       8081/TCP

TargetPort:               80/TCP

NodePort:                   30001/TCP

Endpoints:                10.244.1.10:80

Session Affinity:         None

External Traffic Policy:  Cluster

Events:                   

4.访问

直接访问pod ip:TargetPort （即Endpoints） 10.244.1.10:80 ，生命周期短，一般不用

[root@tensorflow1 serviceTest]# curl "10.244.1.10:80"

It works!

访问service的clusterIP:port，集群内访问，集群外无法不能访问

[root@tensorflow1 serviceTest]# curl "10.100.205.181:8081"

It works!

访问service的MasterNode:nodePort，这里masterNode指的是任意一台k8s集群内物理机，在所有物理机上开端口，主要是为了给集群外机器访问的，如果不需要则不用配置。

[root@tensorflow1 serviceTest]# curl "192.168.1.139:30001"

It works!