1. Headless Service
headless service 需要将 spec.clusterIP 设置成 None。
因为没有ClusterIP，kube-proxy 并不处理此类服务，因为没有load balancing或 proxy 代理设置，在访问服务的时候回返回后端的全部的Pods IP地址，主要用于开发者自己根据pods进行负载均衡器的开发(设置了selector) 或 StatefulSet.
2. Test Headless Service With selectors
$cat deployment.yamlapiVersion: extensions/v1beta1kind: Deploymentmetadata: ?name: nginx-deploymentspec: ?replicas: 2 # tells deployment to run 2 pods matching the template ?template: # create pods using pod definition in this template ???metadata: ?????# unlike pod-nginx.yaml, the name is not included in the meta data as a unique name is ?????# generated from the deployment name ?????labels: ???????app: nginx_test ???spec: ?????containers: ?????- name: nginx ???????image: nginx:1.7.9 ???????ports: ???????- containerPort: 80
$ cat headless_service.yamlkind: ServiceapiVersion: v1metadata: ?name: nginx-servicespec: ?selector: ???app: nginx_test ?ports: ???- protocol: TCP ?????port: 80 ?????targetPort: 80 ?clusterIP: None
通过dns访问，会返回后端pods的列表
登录到Cluster的内部pod
nslookup nginx-servicenslookup: can‘t resolve ‘(null)‘: Name does not resolveName: ?????nginx-serviceAddress 1: 10.10.23.36Address 2: 10.10.23.39
Kubernetes Headless Service
原文地址：https://www.cnblogs.com/vincenshen/p/9642156.html