deployment和service定义如下：
代码语言：javascript复制# cat service-via-node-port.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
name: hostnames
spec:
selector:
matchLabels:
app: hostnames
replicas: 3
template:
metadata:
labels:
app: hostnames
spec:
containers:
- name: hostnames
image: k8s.gcr.io/serve_hostname
ports:
- containerPort: 9376
protocol: TCP
---
apiVersion: v1
kind: Service
metadata:
name: hostnames
spec:
type: NodePort
selector:
app: hostnames
ports:
- name: default
protocol: TCP
port: 9376
nodePort: 30000这里部署的hostnames应用主要功能是当访问它的9376端口时，会返回它自己的主机名，创建相应的deployment和service：
代码语言：javascript复制# k apply -f service-via-node-port.yaml
deployment.apps/hostnames created
service/hostnames created
# k get deploy hostnames
NAME READY UP-TO-DATE AVAILABLE AGE
hostnames 3/3 3 3 11s
# k get po
NAME READY STATUS RESTARTS AGE
hostnames-85bc9c579-bz98x 1/1 Running 0 17s
hostnames-85bc9c579-djjqm 1/1 Running 0 17s
hostnames-85bc9c579-k2kzt 1/1 Running 0 17s查询service和相应的endpoints，并通过任意节点的ip和指定的node port（30000）访问pod:
代码语言：javascript复制# k get svc hostnames
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
hostnames NodePort 10.0.92.250 <none> 9376:30000/TCP 40s
# k get ep hostnames
NAME ENDPOINTS AGE
hostnames 10.1.161.13:9376,10.1.166.150:9376,10.1.166.188:9376 47s
# k get no
NAME STATUS ROLES AGE VERSION
172.16.217.225 Ready etcd,master,proxy 51d v1.13.5 icp-ee
172.16.244.153 Ready management,worker 51d v1.13.5 icp-ee
172.16.244.158 Ready worker 51d v1.13.5 icp-ee
# curl 172.16.217.225:30000
hostnames-85bc9c579-djjqm
# curl 172.16.244.153:30000
hostnames-85bc9c579-djjqm
# curl 172.16.244.158:30000
hostnames-85bc9c579-djjqm
# curl 172.16.244.158:30000
hostnames-85bc9c579-k2kzt
# curl 172.16.244.153:30000
hostnames-85bc9c579-bz98x使用node port模式的service时，可以通过集群任意节点ip访问部署的hostnames，并且查看service的endpoints，可以看到其后端代理的pod的ip，当某个pod出现问题时，kubernetes会将其从service的endpoints中移除，确保应用能正常的被访问，以上就是node port模式的service。
LEo at 00:12
