Gateway

统一网关GateWay

1. 实现身份认证和权限校验
2. 服务路由、负载均衡
3. 请求限流

Mavne依赖

1. 引入Nacos服务发现依赖

<!--        nacos服务发现依赖-->
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
        </dependency>

2. gateway服务依赖

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

配置文件

server:
  port: 10010
spring:
  application:
    name: gateway
  cloud:
    nacos:
      server-addr: localhost:9998 # Nacos地址
    gateway:
      routes:
        - id: user-service # 路由标识，必须唯一
          uri: lb://userservice # 负载均衡，路由的目标地址
          predicates: # 路由断言  判断请求是否符合规则
            - Path=/user/** # 判断路径是是否以/user开头
        - id: order-service
          uri: lb://orderservice
          predicates:
            - Path=/order/**

直接通过网关进行访问

Route Predicate Factories

1. The After Route Predicate Factory

再次访问直接404

GatewayFilter

GatewayFilter是网关中提供的一种过滤器，可以对进入网关的请求和微服务返回的响应做处理

添加请求头信息(局部过滤器)

服务端处理代码

    /**
     * 路径： /user/110
     *
     * @param id 用户id
     * @return 用户
     */
    @GetMapping("/{id}")
    public User queryById(@PathVariable("id") Long id, @RequestHeader(value = "Truth",required = false) String truth) {
        log.info("truth: " + truth);
        return userService.queryById(id);
    }

控制台接收信息

全局过滤器

GlobalFilter

前面介绍到的Filter工厂的逻辑都是Spring写死的，而GlobalFilter的逻辑需要自己写代码实现

package cn.pickle.gateway;

import org.springframework.cloud.gateway.filter.GatewayFilterChain;
import org.springframework.cloud.gateway.filter.GlobalFilter;
import org.springframework.core.Ordered;
import org.springframework.core.annotation.Order;
import org.springframework.http.HttpStatus;
import org.springframework.http.server.reactive.ServerHttpRequest;
import org.springframework.stereotype.Component;
import org.springframework.util.MultiValueMap;
import org.springframework.web.server.ServerWebExchange;
import reactor.core.publisher.Mono;

/**
 * @author Pickle
 * @version V1.0
 * @date 2022/12/11 14:52
 */
//order 规定过滤器的执行顺序，值越小优先级越高
@Order(value = -1)
@Component
public class AuthorizeFilter implements GlobalFilter {
    @Override
    public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
        //1. Get request parameters
        final ServerHttpRequest request = exchange.getRequest();
        final MultiValueMap<String, String> params = request.getQueryParams();

        //2. Get the Authorization in the request parameter
        final String auth = params.getFirst("authorization");

        //3. Determine whether the parameter value is equal to admin
        if("admin".equals(auth)){
            //4. true -- let go
            return chain.filter(exchange);
        }

        //5. false -- intercept
            //5.1 set status code 401
        exchange.getResponse().setStatusCode(HttpStatus.UNAUTHORIZED);

        return exchange.getResponse().setComplete();
    }
}

其中优先级还可以通过实现Ordered中的getOrder方法实现

package cn.pickle.gateway;

import org.springframework.cloud.gateway.filter.GatewayFilterChain;
import org.springframework.cloud.gateway.filter.GlobalFilter;
import org.springframework.core.Ordered;
import org.springframework.core.annotation.Order;
import org.springframework.http.HttpStatus;
import org.springframework.http.server.reactive.ServerHttpRequest;
import org.springframework.stereotype.Component;
import org.springframework.util.MultiValueMap;
import org.springframework.web.server.ServerWebExchange;
import reactor.core.publisher.Mono;

/**
 * @author Pickle
 * @version V1.0
 * @date 2022/12/11 14:52
 */
//order 规定过滤器的执行顺序，值越小优先级越高
//@Order(value = -1)
@Component
public class AuthorizeFilter implements GlobalFilter, Ordered{
    @Override
    public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
        //1. Get request parameters
        final ServerHttpRequest request = exchange.getRequest();
        final MultiValueMap<String, String> params = request.getQueryParams();

        //2. Get the Authorization in the request parameter
        final String auth = params.getFirst("authorization");

        //3. Determine whether the parameter value is equal to admin
        if("admin".equals(auth)){
            //4. true -- let go
            return chain.filter(exchange);
        }

        //5. false -- intercept
            //5.1 set status code 401
        exchange.getResponse().setStatusCode(HttpStatus.UNAUTHORIZED);

        return exchange.getResponse().setComplete();
    }

    @Override
    public int getOrder() {
        return -1;
    }
}

测试访问

过滤器的执行顺序

当过滤器的Order值相等时，会按照defaultFilter > 路由过滤器 > GlobalFilter的顺序执行

CORS(Cross-origin resource sharing)跨域配置

支持CORS请求的浏览器一旦发现ajax请求跨域，会对请求做一些特殊处理，对于已经实现CORS接口的服务端，接受请求，并做出回应。

有一种情况比较特殊，如果我们发送的跨域请求为“非简单请求”，浏览器会在发出此请求之前首先发送一个请求类型为OPTIONS的“预检请求”，验证请求源是否为服务端允许源，这些对于开发这来说是感觉不到的，由浏览器代理。

  globalcors: # 全局的跨域处理
        add-to-simple-url-handler-mapping: true # 解决options请求被拦截问题
        corsConfigurations:
          '[/**]':
            allowedOrigins: # 允许哪些网站的跨域请求
              - "http://localhost:5500"
              - "http://www.pickle.com"
            allowedMethods: # 允许的跨域ajax的请求方式
              - "GET"
              - "POST"
              - "DELETE"
              - "PUT"
              - "OPTIONS"
            allowedHeaders: "*" # 允许在请求中携带的头信息
            allowCredentials: true # 是否允许携带cookie
            maxAge: 360000 # 这次跨域检测的有效期
            

配置之前

配置之后