kubernetes port nodePort targetPort 理解

prollerweg

port
　　The port that the service is exposed on the service’s cluster ip (virsual ip). Port is the service port which is accessed by others with cluster ip.
　　即，这里的port表示：service暴露在cluster ip上的端口，<cluster ip>:port 是提供给集群内部客户访问service的入口。
nodePort
　　On top of having a cluster-internal IP, expose the service on a port on each node of the cluster (the same port on each node). You'll be able to contact the service on any<nodeIP>:nodePortaddress. So nodePort is alse the service port which can be accessed by the node ip by others with external ip.
　　首先，nodePort是kubernetes提供给集群外部客户访问service入口的一种方式（另一种方式是LoadBalancer），所以，<nodeIP>:nodePort 是提供给集群外部客户访问service的入口。
targetPort
　　The port on the pod that the service should proxy traffic to.
　　targetPort很好理解，targetPort是pod上的端口，从port和nodePort上到来的数据最终经过kube-proxy流入到后端pod的targetPort上进入容器。
　　转： http://blog.csdn.net/xinghun_4/article/details/50492041