微服务 之 统一网关

本文的示例代码参考gateway-app / gateway-zuul / gateway-springcloud

简介

• 功能

路由

过滤 => 权限、监控、限流、日志

• 价值

复用 => 限流、日志

安全 => 权限、监控

应用

spring init -b=2.2.10.RELEASE -j=1.8 -l=kotlin -d=web --build=gradle gateway-app && cd gateway-app

vim src/main/kotlin/com/example/gatewayapp/BooksController.kt

package com.example.gatewayapp

import org.springframework.web.bind.annotation.GetMapping
import org.springframework.web.bind.annotation.PathVariable
import org.springframework.web.bind.annotation.RequestHeader
import org.springframework.web.bind.annotation.RestController

@RestController
class BooksController {
    @GetMapping("/{id}")
    fun findById(@PathVariable id: Long,
                 @RequestHeader(name = "Proxy", required = false) proxy: String?): String {
        return  (proxy ?: "") + "|books => " + id;
    }
}

vim ./src/main/resources/application.properties

server.port=5001

./gradlew bootrun

curl localhost:8090/2
# |books => 2

curl localhost:5001/2 -H "Proxy: local"
# local|books => 2

Netflix Zuul

spring init -b=2.2.10.RELEASE -j=1.8 -l=kotlin -d=web,cloud-zuul --build=gradle gateway-zuul && cd gateway-zuul

vim src/main/kotlin/com/example/gatewayzuul/DemoApplication.kt

package com.example.gatewayzuul

import org.springframework.boot.autoconfigure.SpringBootApplication
import org.springframework.boot.runApplication
import org.springframework.cloud.netflix.zuul.EnableZuulProxy

@EnableZuulProxy
@SpringBootApplication
class DemoApplication

fun main(args: Array<String>) {
    runApplication<DemoApplication>(*args)
}

vim src/main/resources/application.properties

server.port=6001
spring.application.name=gateway-zuul
zuul.routes.books.path: /books/**
zuul.routes.books.url: http://localhost:5001/

vim src/main/kotlin/com/example/gatewayzuul/SimpleFilter.kt

package com.example.gatewayzuul;

import com.netflix.zuul.ZuulFilter;
import com.netflix.zuul.context.RequestContext;
import com.netflix.zuul.exception.ZuulException;
import org.springframework.stereotype.Component;

@Component
public class SimpleFilter extends ZuulFilter {

    @Override
    public String filterType() {
        return "pre";
    }

    @Override
    public int filterOrder() {
        return 0;
    }

    @Override
    public boolean shouldFilter() {
        return true;
    }

    @Override
    public Object run() throws ZuulException {
        RequestContext ctx = RequestContext.getCurrentContext();
        ctx.addZuulRequestHeader("Proxy", "SimpleFilter");
        return null;
    }
}

./gradlew bootrun

curl localhost:5001/2
# |books => 2

curl localhost:6001/books/2
# gateway-zuul|books => 2

Spring Cloud Gateway

spring init -b=2.2.10.RELEASE -j=1.8 -l=kotlin -d=cloud-gateway --build=gradle gateway-springcloud && cd gateway-springcloud

rm src/main/resources/application.properties

vim src/main/resources/application.yml

server:
  port: 7001
spring:
  application:
    name: gateway-springcloud
  cloud:
    gateway:
      routes:
        - id: books_route
          uri: http://localhost:5001/
          predicates:
            - Path=/books/**
          filters:
            - StripPrefix=1

./gradlew bootrun

curl localhost:5001/2
# |books => 2

curl localhost:7001/books/2 -H "Proxy: gateway-springcloud"
# gateway-springcloud|books => 2

参考

• Routing and Filtering

• Spring REST with a Zuul Proxy

• Spring Cloud Gateway 入门

• 微服务网关实战——Spring Cloud Gateway