分布式系统 - 网关篇之SpringCloud Gateway

Posted 2021-04-23 一只幸福的小象

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一、整合SpringCloud Gateway

加入pom依赖

<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-gateway</artifactId>
    <version>2.2.1.RELEASE</version>
</dependency>

Gateway不需要配置其他注解，直接配置yml即可

spring:
 application:
 name: sunway-gateway
 gateway:
      # 路由转发规则
 routes:
        - id: ES
 uri: lb://es-service
 predicates:
            - Path=/es/**
 filters:
            - StripPrefix=1

二、整合Swagger文档

微服务项目中，通常把Swagger2单独放到公共模块中，然后需要的项目引一下依赖，最终通过网关的文档地址去转发访问各个微服务的接口文档。

swagger 公共模块 pom依赖

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <!-- bootstrap版本的页面 地址 为/doc.html -->
        <dependency>
            <groupId>com.github.xiaoymin</groupId>
            <artifactId>swagger-bootstrap-ui</artifactId>
            <version>1.9.3</version>
        </dependency>
        <dependency>
            <groupId>io.springfox</groupId>
            <artifactId>springfox-swagger2</artifactId>
            <version>2.9.2</version>
        </dependency>
        <!-- 原始swagger页面 地址 为/swagger-ui.html -->
        <dependency>
            <groupId>io.springfox</groupId>
            <artifactId>springfox-swagger-ui</artifactId>
            <version>2.9.2</version>
        </dependency>
    </dependencies>

swagger配置类

package com.sunway.swagger.config;

import com.github.xiaoymin.swaggerbootstrapui.annotations.EnableSwaggerBootstrapUI;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.ResourceHandlerRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
import springfox.documentation.builders.ApiInfoBuilder;
import springfox.documentation.builders.ParameterBuilder;
import springfox.documentation.builders.PathSelectors;
import springfox.documentation.builders.RequestHandlerSelectors;
import springfox.documentation.schema.ModelRef;
import springfox.documentation.service.ApiInfo;
import springfox.documentation.service.Contact;
import springfox.documentation.service.Parameter;
import springfox.documentation.spi.DocumentationType;
import springfox.documentation.spring.web.plugins.Docket;
import springfox.documentation.swagger2.annotations.EnableSwagger2;

import java.util.Collections;
import java.util.List;

@Configuration
@EnableSwagger2
@EnableSwaggerBootstrapUI
public class Swagger2Config implements WebMvcConfigurer {

    @Value("${spring.application.name}")
    private String applicationName;

    @Bean
    public Docket esDocket() {
        return new Docket(DocumentationType.SWAGGER_2)
                .apiInfo(getInfo(applicationName + "服务接口"))
                .select()
                .apis(RequestHandlerSelectors.basePackage("com.sunway"))
                .paths(PathSelectors.any())
                .build()
                .globalOperationParameters(getParameterList());
    }

    /**
 * 添加全局请求头
 *
 * @return java.util.List<springfox.documentation.service.Parameter>
 * @date 2021/1/27 12:52
 */
    private List<Parameter> getParameterList() {
        //创建全局参数用于测试(每个请求都带一个header参数"X-token")
        return Collections.singletonList(new ParameterBuilder().required(false)
                .modelRef(new ModelRef("string"))
                .parameterType("header")
                .name("X-token")
                .description("认证信息")
                .build()
        );
    }

    /**
 * 整体说明信息
 *
 * @return ApiInfo
 */
    private ApiInfo getInfo(String description) {
        //创建文档的整体说明对象(作者、描述、标题、版本)
        return new ApiInfoBuilder().contact(new Contact("标题", "", ""))
                .title("标题")
                .description(description)
                .version("1.0")
                .build();
    }

    @Override
    public void addResourceHandlers(ResourceHandlerRegistry registry) {
        registry.addResourceHandler("/**")
                .addResourceLocations("classpath:/META-INF/resources/")
                .addResourceLocations("classpath:/resources/")
                .addResourceLocations("classpath:/static/")
                .addResourceLocations("classpath:/public/");
    }
}

这里有个问题就是 swagger依赖是基于spring webmvc的，而springCloud gateway是基于 webflux的，这两者会冲突导致启动失败，所以我们可以在gateway中单独引入swagger的依赖包，整合到webflux上面：

        <dependency>
            <groupId>com.github.xiaoymin</groupId>
            <artifactId>swagger-bootstrap-ui</artifactId>
            <version>1.9.3</version>
        </dependency>
        <dependency>
            <groupId>io.springfox</groupId>
            <artifactId>springfox-swagger2</artifactId>
            <version>2.9.2</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-gateway</artifactId>
        </dependency>

如何整合？如下配置:

此配置会拉取已经注册路由的ID，作为分组名，然后取路由的Path作为转发路径，/v2/api-docs接口返回的是接口的JSON信息，转发地址即是 /{路由Path}/v2/api-docs，就能拿到各个服务的api文档了。

@Component
@Primary
@AllArgsConstructor
public class CloudSwagger2Config implements SwaggerResourcesProvider {

    public static final String API_URI = "/v2/api-docs";
    private final RouteLocator routeLocator;
    private final GatewayProperties gatewayProperties;

    @Override
    public List<SwaggerResource> get() {
        List<SwaggerResource> resources = new ArrayList<>();
        List<String> routes = new ArrayList<>();
        //取出gateway的route
        routeLocator.getRoutes().subscribe(route -> routes.add(route.getId()));
        //结合配置的route-路径(Path)，和route过滤，只获取有效的route节点
        gatewayProperties.getRoutes().stream().filter(routeDefinition -> routes.contains(routeDefinition.getId()))
                .forEach(routeDefinition -> routeDefinition.getPredicates().stream()
                        .filter(predicateDefinition -> ("Path").equalsIgnoreCase(predicateDefinition.getName()))
                        .forEach(predicateDefinition -> resources.add(swaggerResource(routeDefinition.getId(),
                                predicateDefinition.getArgs().get(NameUtils.GENERATED_NAME_PREFIX + "0")
                                        .replace("/**", API_URI)))));
        return resources;
    }

    private SwaggerResource swaggerResource(String name, String location) {
        SwaggerResource swaggerResource = new SwaggerResource();
        swaggerResource.setName(name);
        swaggerResource.setLocation(location);
        swaggerResource.setSwaggerVersion("2.0");
        return swaggerResource;
    }
}

接着自定义一套swagger文档的配置接口

package com.sunway.gateway.swagger;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import reactor.core.publisher.Mono;
import springfox.documentation.swagger.web.*;

import java.util.Optional;

@RestController
@RequestMapping("/swagger-resources")
public class SwaggerHandler {

    @Autowired(required = false)
    private SecurityConfiguration securityConfiguration;
    @Autowired(required = false)
    private UiConfiguration uiConfiguration;

    private final SwaggerResourcesProvider swaggerResources;

    @Autowired
    public SwaggerHandler(SwaggerResourcesProvider swaggerResources) {
        this.swaggerResources = swaggerResources;
    }


    @GetMapping("/configuration/security")
    public Mono<ResponseEntity<SecurityConfiguration>> securityConfiguration() {
        return Mono.just(new ResponseEntity<>(
                Optional.ofNullable(securityConfiguration).orElse(SecurityConfigurationBuilder.builder().build()), HttpStatus.OK));
    }

    @GetMapping("/configuration/ui")
    public Mono<ResponseEntity<UiConfiguration>> uiConfiguration() {
        return Mono.just(new ResponseEntity<>(
                Optional.ofNullable(uiConfiguration).orElse(UiConfigurationBuilder.builder().build()), HttpStatus.OK));
    }

    @GetMapping("")
    public Mono<ResponseEntity> swaggerResources() {
        return Mono.just((new ResponseEntity<>(swaggerResources.get(), HttpStatus.OK)));
    }
}

三、自定义拦截器

需要实现GlobalFilter，Ordered接口，order越大，优先级越低。


@Slf4j
@Component
public class CustomGlobalFilter implements GlobalFilter, Ordered {

    private static final String AUTHORIZE_TOKEN = "Authorize";

    @Override
    public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
// String token = exchange.getRequest().getHeaders().getFirst(AUTHORIZE_TOKEN);
// // token 鉴权
// if (StringUtils.isBlank(token)) {
// exchange.getResponse().setStatusCode(HttpStatus.UNAUTHORIZED);
// return exchange.getResponse().setComplete();
// }

        return chain.filter(exchange);
    }

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