十、Gateway网关服务搭建和配置

1. 新建服务，pom文件

新建gateway-server服务，pom文件如下：

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.2.12.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.test</groupId>
    <artifactId>gateway-server</artifactId>
    <version>1.0.0-SNAPSHOT</version>
    <name>gateway-server</name>
    <description>gateway网关服务</description>

    <properties>
        <java.version>1.8</java.version>
        <spring-cloud-alibaba.version>2.2.1.RELEASE</spring-cloud-alibaba.version>
        <spring-cloud.version>Hoxton.SR9</spring-cloud.version>
    </properties>

    <dependencies>
        <!-- 测试路由用的，
        可访问 http://ip:port/actuator/gateway/routes 
        查看路由是否配置生效 -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-actuator</artifactId>
        </dependency>
        <!-- Nacos注册和服务配置，网关也要放到nacos上的 -->
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-config</artifactId>
        </dependency>
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
        </dependency>
        <!-- 后续关联sentinel用 -->
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-sentinel</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-gateway</artifactId>
        </dependency>
        <!-- 使用openfeign的 -->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-openfeign</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <scope>runtime</scope>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
            <exclusions>
                <exclusion>
                    <groupId>org.junit.vintage</groupId>
                    <artifactId>junit-vintage-engine</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>javax.servlet-api</artifactId>
        </dependency>
        
        <!-- log4j2 -->
        <!-- Spring Boot官方文档中解释，在启用spring-boot-starter后会默认使用logback作为日志框架， 本项目选用log4j2,因此需要全局exclude掉Spring 
            Boot默认日志 -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter</artifactId>
            <exclusions>
                <exclusion>
                    <groupId>org.springframework.boot</groupId>
                    <artifactId>spring-boot-starter-logging</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-log4j2</artifactId>
        </dependency>
    </dependencies>

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>${spring-cloud.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
            <dependency>
                <groupId>com.alibaba.cloud</groupId>
                <artifactId>spring-cloud-alibaba-dependencies</artifactId>
                <version>${spring-cloud-alibaba.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

    <build>
        <finalName>gateway-service</finalName>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <configuration>
                    <excludes>
                        <exclude>
                            <groupId>org.projectlombok</groupId>
                            <artifactId>lombok</artifactId>
                        </exclude>
                    </excludes>
                </configuration>
            </plugin>
            <!-- 编译打包跳过test -->
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-surefire-plugin</artifactId>
                <configuration>
                    <skip>true</skip>
                </configuration>
            </plugin>
        </plugins>
    </build>
</project>

特别注意：

• Spring Cloud Gateway 不使用 Web 作为服务器，而是 使用 WebFlux 作为服务器，Gateway 项目已经依赖了 starter-webflux，所以这里 千万不要依赖 starter-web
• 由于过滤器等功能依然需要 Servlet 支持，故这里还需要依赖 javax.servlet:javax.servlet-api

2. 跨域配置

因为不是Web 作为服务器，和其他的稍有不同

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.http.HttpHeaders;
import org.springframework.web.cors.CorsConfiguration;
import org.springframework.web.cors.reactive.CorsWebFilter;
import org.springframework.web.cors.reactive.UrlBasedCorsConfigurationSource;
import org.springframework.web.reactive.config.CorsRegistry;
import org.springframework.web.reactive.config.WebFluxConfigurer;

/**
 * 跨域配置
 */
@Configuration
public class CorsConfig implements WebFluxConfigurer 
  
  @Override
  public void addCorsMappings(CorsRegistry registry) {
      registry.addMapping("/**")
              .allowCredentials(true)
              .allowedOrigins("*")
              .allowedHeaders("*")
              .allowedMethods("*")
              .exposedHeaders(HttpHeaders.SET_COOKIE);
  }
  
  /**
   * 跨域过滤器
   * @return
   */
  @Bean
  public CorsWebFilter corsWebFilter() {
      CorsConfiguration corsConfiguration = new CorsConfiguration();
      corsConfiguration.setAllowCredentials(true);
      corsConfiguration.addAllowedHeader("*");
      corsConfiguration.addAllowedMethod("*");
      corsConfiguration.addAllowedOrigin("*");
      corsConfiguration.addExposedHeader(HttpHeaders.SET_COOKIE);
      UrlBasedCorsConfigurationSource corsConfigurationSource = new UrlBasedCorsConfigurationSource();
      corsConfigurationSource.registerCorsConfiguration("/**", corsConfiguration);
      return new CorsWebFilter(corsConfigurationSource);
  }
}

3. 启动文件添加@EnableFeignClients注解

@SpringBootApplication
@EnableDiscoveryClient
@EnableFeignClients
public class GatewayServerApplication {

    public static void main(String[] args) {
        SpringApplication.run(GatewayServerApplication.class, args);
    }

}

4. nacos中配置信息

# 1.server
server:
  port: 10000
# 2.log
logging:
  level:
    org.springframework.cloud.gateway: info
# 3. openfeign
feign:
  sentinel:
    enabled: true
# 4. 为了监控网关
management:
  endpoints:
    web:
      exposure:
        include: "*"
# 5.spring
spring: 
  # 统一设置返回的时间格式
  jackson: 
    date-format: yyyy-MM-dd HH:mm:ss
    time-zone: GMT+8
    default-property-inclusion: NON_NULL
  cloud: 
    gateway:
      discovery:
        locator:
          enabled: true
      routes:
          # 自定义路由 ID
        - id: service-dict
          # 采用 LoadBalanceClient 方式请求，以 lb:// 开头，后面的是注册在 Nacos 上的服务名
          uri: lb://service-dict
          # Predicate 翻译过来是“谓词”的意思，必须，主要作用是匹配用户的请求，有很多种用法
          predicates:
            # 路径匹配，以 api 开头，直接配置是不生效的，看 filters 配置
            - Path=/api/dict/**
          filters:
            # 前缀过滤，默认配置下，我们的请求路径是 http://localhost:9000/myshop-service-consumer-item/** 这时会路由到指定的服务
            # 此处配置去掉 1 个路径前缀，再配置上面的 Path=/api/**，就能按照 http://localhost:9000/api/** 的方式访问了
            - StripPrefix=1
        - id: service-file
          uri: lb://service-file
          predicates:
            - Path=/api/file/**
          filters:
            - StripPrefix=1