kubernetes in a variety of port doubts

Series catalog

When scheduling kubernetes, Deployment of Pod item has containerPort, Service documents in the port, targetPort, nodePort, these pod concept sometimes can make people feel very confused, here by way of example to brief the meaning of the various port

apiVersion: extensions/v1beta1
kind: Deployment
metadata:
name: tomcat-deployment
spec:
replicas: 3
template:
metadata:
labels:
app: tomcat
tier: frontend
spec:
containers:
    name: tomcat
    image: docker.cinyi.com:443/tomcat
    ports:
    containerPort: 80   #这里containerPort是容器内部的port

apiVersion: v1
kind: Service
metadata:
name: tomcat-server
spec:
type: NodePort
ports:
    port: 11111  #service暴露在cluster ip上的端口，通过<cluster ip>:port访问服务,通过此端口集群内的服务可以相互访问
    targetPort: 8080  #Pod的外部访问端口，port和nodePort的数据通过这个端口进入到Pod内部，Pod里面的containers的端口映射到这个端口，提供服务
    nodePort: 30001 #Node节点的端口，<nodeIP>:nodePort 是提供给集群外部客户访问service的入口
selector:
tier: frontend