SpringCloud微服务实战——搭建企业级开发框架（十九）：Gateway使用knife4j聚合微服务文档

  本章介绍Spring Cloud Gateway网关如何集成knife4j,通过网关聚合所有的Swagger微服务文档

1. gitegg-gateway中引入knife4j依赖,如果没有后端代码编写的话,仅仅引入一个swagger的前端ui模块就可以了

        <dependency>
            <groupId>io.springfox</groupId>
            <artifactId>springfox-swagger2</artifactId>
        </dependency>
        <dependency>
            <groupId>com.github.xiaoymin</groupId>
            <artifactId>knife4j-spring-ui</artifactId>
        </dependency>

2. 修改配置文件，增加knife4j、Swagger2的配置

server:
  port: 80
spring:
  application:
    name: gitegg-service-gateway
  cloud:
    nacos:
      discovery:
        server-addr: 127.0.0.1:8848
      config:
        server-addr: 127.0.0.1:8848
        file-extension: yaml
        group: DEFAULT_GROUP
        enabled: true
    gateway:
      discovery:
        locator:
          enabled: true
      routes:
        - id: gitegg-service-system
          uri: lb://gitegg-service-system
          predicates:
            - Path=/gitegg-system/**
          filters:
            - SwaggerHeaderFilter
            - StripPrefix=1
        - id: gitegg-service-base
          uri: lb://gitegg-service-base
          predicates:
            - Path=/gitegg-base/**
          filters:
            - SwaggerHeaderFilter
            - StripPrefix=1

文档聚合业务编码

  在我们使用Spring Boot等单体架构集成swagger项目时,是通过对包路径进行业务分组,然后在前端进行不同模块的展示,而在微服务架构下,我们的一个服务就类似于原来我们写的一个业务组。
  springfox-swagger提供的分组接口是swagger-resource,返回的是分组接口名称、地址等信息。
  在Spring Cloud微服务架构下,我们需要重写该接口,主要是通过网关的注册中心动态发现所有的微服务文档,代码如下：

package com.gitegg.gateway.config;

import lombok.AllArgsConstructor;
import lombok.extern.slf4j.Slf4j;
import org.springframework.cloud.gateway.config.GatewayProperties;
import org.springframework.cloud.gateway.route.RouteLocator;
import org.springframework.cloud.gateway.support.NameUtils;
import org.springframework.context.annotation.Primary;
import org.springframework.stereotype.Component;
import springfox.documentation.swagger.web.SwaggerResource;
import springfox.documentation.swagger.web.SwaggerResourcesProvider;

import java.util.ArrayList;
import java.util.List;

@Slf4j
@Component
@Primary
@AllArgsConstructor
public class SwaggerResourceConfig implements SwaggerResourcesProvider {

    private final RouteLocator routeLocator;
    private final GatewayProperties gatewayProperties;


    @Override
    public List<SwaggerResource> get() {
        List<SwaggerResource> resources = new ArrayList<>();
        List<String> routes = new ArrayList<>();
        routeLocator.getRoutes().subscribe(route -> routes.add(route.getId()));
        gatewayProperties.getRoutes().stream().filter(routeDefinition -> routes.contains(routeDefinition.getId())).forEach(route -> {
            route.getPredicates().stream()
                    .filter(predicateDefinition -> ("Path").equalsIgnoreCase(predicateDefinition.getName()))
                    .forEach(predicateDefinition -> resources.add(swaggerResource(route.getId(),
                            predicateDefinition.getArgs().get(NameUtils.GENERATED_NAME_PREFIX + "0")
                                    .replace("**", "v2/api-docs?group=1.X版本"))));
        });

        return resources;
    }

    private SwaggerResource swaggerResource(String name, String location) {
        log.info("name:{},location:{}",name,location);
        SwaggerResource swaggerResource = new SwaggerResource();
        swaggerResource.setName(name);
        swaggerResource.setLocation(location);
        swaggerResource.setSwaggerVersion("1.0.0");
        return swaggerResource;
    }
}

package com.gitegg.gateway.filter;

import org.apache.commons.lang.StringUtils;
import org.springframework.cloud.gateway.filter.GatewayFilter;
import org.springframework.cloud.gateway.filter.factory.AbstractGatewayFilterFactory;
import org.springframework.http.server.reactive.ServerHttpRequest;
import org.springframework.stereotype.Component;
import org.springframework.web.server.ServerWebExchange;

@Component
public class SwaggerHeaderFilter extends AbstractGatewayFilterFactory {
    private static final String HEADER_NAME = "X-Forwarded-Prefix";

    private static final String URI = "/v2/api-docs";

    @Override
    public GatewayFilter apply(Object config) {
        return (exchange, chain) -> {
            ServerHttpRequest request = exchange.getRequest();
            String path = request.getURI().getPath();
            if (!StringUtils.endsWithIgnoreCase(path,URI )) {
                return chain.filter(exchange);
            }
            String basePath = path.substring(0, path.lastIndexOf(URI));
            ServerHttpRequest newRequest = request.mutate().header(HEADER_NAME, basePath).build();
            ServerWebExchange newExchange = exchange.mutate().request(newRequest).build();
            return chain.filter(newExchange);
        };
    }
}

package com.gitegg.gateway.handler;

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.RestController;
import reactor.core.publisher.Mono;
import springfox.documentation.swagger.web.*;

import java.util.Optional;

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

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

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

3. 访问gitegg-gateway服务地址http://127.0.0.1/doc.html，可以看到聚合后的文档

本文源码在 https://gitee.com/wmz1930/GitEgg 的chapter-19分支。

GitEgg-Cloud是一款基于SpringCloud整合搭建的企业级微服务应用开发框架，开源项目地址:

Gitee: https://gitee.com/wmz1930/GitEgg

GitHub: https://github.com/wmz1930/GitEgg