ref :
http://microservices.io/patterns/apigateway.html
https://www.nginx.com/blog/building-microservices-using-an-api-gateway
https://cloud.spring.io/spring-cloud-netflix/single/spring-cloud-netflix.html#_router_and_filter_zuul
Building Microservices with Spring Cloud - Intelligent Routing
原文：http://www.cnblogs.com/shouwangzhe-/p/7806865.html