一步一步学SpringCloud--getway配置详解

灰太狼 2022-03-19 15:51 755阅读 0赞

### SpringCloud Gateway配置详解 ###

*  前言
 *  一、引入pom依赖
 *  二、配置文件
 *   *  1、路由配置
     *  2、跨域配置
 *  三、重要的filter
 *   *  1、StripPrefix
     *  2、Hystrix熔断
     *  3、自定义gateway filter
     *  4、自定义限流gateway filter

# 前言 #

在[上一篇文章][Link 1]中简单的介绍了SpringCloud Gateway，同时也对比了一下springcloud的gateway和Netflix的zuul，相信大家也有了一定的认识。此篇文章主要介绍一下gateway是如何配置的。同其他

# 一、引入pom依赖 #

<dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-gateway</artifactId>
    </dependency>

# 二、配置文件 #

## 1、路由配置 ##

spring:
      application:
        name: gateway
      profiles: 
        active: dev
      cloud:
        gateway:
          discovery:
            locator:
              enabled: true
              lower-case-service-id: true
          routes:
          - id: foo # foo服务
            uri: lb://integral-foo
            predicates:
            - Path=/foo-web/**
            filters:
            - StripPrefix=1
    
    server:
      port: 1001
    
    eureka:
      instance:
        instance-id: ${ spring.application.name}:${ random.int}
        prefer-ip-address: true
      client:
        service-url:
          defaultZone: http://localhost:8761/eureka

*  routes：具体的路由信息，是一个数组
    
     *  id：这个路由的唯一id，不定义的话默认为一个uuid
     *  uri：http请求为lb://前缀+服务id；ws请求为lb:ws://前缀+服务id，表示将请求负载到哪个服务上
     *  predicates：表示这个路由的请求匹配规则，只有符合这个规则的请求才会走这个路由。每个规则为并且的关系。
     *  filters：请求转发前的filter
     *  order：这个路由的执行order

## 2、跨域配置 ##

spring:
      application:
        name: gateway
      profiles:
        active: dev
      cloud:
        gateway:
          globalcors:
            corsConfigurations:
               '[/**]':
                  maxAge: 1800
                  allowedOrigins: "*"
                  allowCredentials: true
                  allowedMethods:
                  - GET
                  - POST
                  - PUT
                  - DELETE

*  allowedOrigins：允许的请求
 *  allowCredentials：允许凭证
 *  allowedMethods：允许的方法请求方式

关于跨域的配置SpringCloud Gateway[官网][Link 2]上写的已经很详细了。但是有一点没有提到，前后端交互的时候OPTIONS请求没有跨过去，yml文件里面只能配置get，post，put，delete等等这些请求，配置了OPTIONS不起作用。那么就需要我们再添加一个配置类来专门处理OPTIONS请求。

/** * @author 刘子腾 * @DESCRIPTION 网关跨域 * @create 2019/3/12 */
    @Configuration
    public class CorsConfig { 
        private static final String ALL = "*";
        private static final String MAX_AGE = "18000";
        @Bean
        public WebFilter corsFilter() { 
            return (ServerWebExchange ctx, WebFilterChain chain) -> { 
                ServerHttpRequest request = ctx.getRequest();
                if (!CorsUtils.isCorsRequest(request)) { 
                    return chain.filter(ctx);
                }
                HttpHeaders requestHeaders = request.getHeaders();
                ServerHttpResponse response = ctx.getResponse();
                HttpMethod requestMethod = requestHeaders.getAccessControlRequestMethod();
                HttpHeaders headers = response.getHeaders();
                headers.add(HttpHeaders.ACCESS_CONTROL_ALLOW_ORIGIN, requestHeaders.getOrigin());
                headers.addAll(HttpHeaders.ACCESS_CONTROL_ALLOW_HEADERS, requestHeaders.getAccessControlRequestHeaders());
                if (requestMethod != null) { 
                    headers.add(HttpHeaders.ACCESS_CONTROL_ALLOW_METHODS, requestMethod.name());
                }
                headers.add(HttpHeaders.ACCESS_CONTROL_ALLOW_CREDENTIALS, "true");
                headers.add(HttpHeaders.ACCESS_CONTROL_EXPOSE_HEADERS, ALL);
                headers.add(HttpHeaders.ACCESS_CONTROL_MAX_AGE, MAX_AGE);
                if (request.getMethod() == HttpMethod.OPTIONS) { 
                    response.setStatusCode( HttpStatus.OK);
                    return Mono.empty();
                }
                return chain.filter(ctx);
            };
        }
    }

# 三、重要的filter #

## 1、StripPrefix ##

spring:
      cloud:
        gateway:
          routes:
          - id: nameRoot
            uri: lb://nameservice
            predicates:
            - Path=/name/**
            filters:
            - StripPrefix=1

/name/bar/foo的请求会被转发为http://nameserviceip:nameserviceport/bar/foo

## 2、Hystrix熔断 ##

1）引入pom依赖

<dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-netflix-hystrix</artifactId>
    </dependency>

2）配置文件

spring:
      cloud:
        gateway:
          default-filters:
          routes:
          #------------------------------------------------------------------------
          - id: i5xforyou-biz-auth
            uri: lb://i5xforyou-biz-auth
            predicates:
            - Path= ${ server.servlet.context-path}/auth/**
            filters:
            - StripPrefix= 1
            - name: Hystrix
              args:
                name: authHystrixCommand
                fallbackUri: forward:/hystrixTimeout
    
    
    #设置断路由的超时时间，毫秒
    
    hystrix.command.default.execution.isolation.thread.timeoutInMilliseconds= 30000

name表示HystrixCommand代码的名称，fallbackUri表示触发断路由后的跳转请求url

## 3、自定义gateway filter ##

自定义一个用来检验jwt是否合法的gateway filter为例进行说明。

1）定义一个JwtCheckGatewayFilterFactory类实现GatewayFilterFactory接口。  
类名一定要为filterName + GatewayFilterFactory，如这里定义为JwtCheckGatewayFilterFactory的话，它的filterName就是JwtCheck

2）实现gateway filter的业务逻辑

@Component
    public class JwtCheckGatewayFilterFactory extends AbstractGatewayFilterFactory<Object> { 
    
        @Override
        public GatewayFilter apply(Object config) { 
            return (exchange, chain) -> { 
                //return chain.filter(exchange);
                String jwtToken = exchange.getRequest().getHeaders().getFirst("Authorization");
                //校验jwtToken的合法性
                if (JwtUtil.verifyToken(jwtToken) != null) { 
                    //合法
                    return chain.filter(exchange);
                }
    
    
                //不合法
                ServerHttpResponse response = exchange.getResponse();
                //设置headers
                HttpHeaders httpHeaders = response.getHeaders();
                httpHeaders.add("Content-Type", "application/json; charset=UTF-8");
                httpHeaders.add("Cache-Control", "no-store, no-cache, must-revalidate, max-age=0");
                //设置body
                JsonPackage jsonPackage = new JsonPackage();
                jsonPackage.setStatus(110);
                jsonPackage.setMessage("未登录或登录超时");
                DataBuffer bodyDataBuffer = response.bufferFactory().wrap(jsonPackage.toJSONString().getBytes());
    
                return response.writeWith(Mono.just(bodyDataBuffer));
            };
        }
    
    }

3）配置文件

## 4、自定义限流gateway filter ##

gateway自带的RequestRateLimiter可定制的内容太少，真正用的话，需要：

1.  自定义限流后的response返回值
2.  不同的key（即接口）限流数不同

[Link 1]: https://blog.csdn.net/liuziteng0228/article/details/86933095
[Link 2]: https://cloud.spring.io/spring-cloud-gateway/spring-cloud-gateway.html#_cors_configuration