Ocelot网关Swagger无法显示微服务端点问题求助

问题描述 #

• 通过Ocelot网关可正常调用points-service微服务接口，但Swagger无法加载该微服务的端点
• 网关日志出现警告：

warn: Ocelot.Responder.Middleware.ResponderMiddleware[0]
2024-10-30 21:04:21 requestId: 0HN7P2MKOVR6R:00000001, previousRequestId: No PreviousRequestId, message: 'Error Code: UnableToFindDownstreamRouteError Message: Failed to match Route configuration for upstream path: /, verb: GET. errors found in ResponderMiddleware. Setting error response for request path:/, request method: GET'

• 在网关容器内执行curl http://points-service:5001/swagger/v1/swagger.json可正常获取微服务Swagger配置文件

排查与修复方案 #

1. 补充Swagger代理路由并修正Swagger地址 #

当前Ocelot路由仅覆盖了/api/*路径，缺少Swagger相关路径的代理规则，且SwaggerEndPoints中配置的是微服务直接地址，无法通过网关正常访问。修改ocelot.json如下：

{
  "Routes": [
    // 原有API路由
    {
      "DownstreamPathTemplate": "/api/{everything}",
      "DownstreamScheme": "http",
      "DownstreamHostAndPorts": [
        {
          "Host": "points-service",
          "Port": 5001
        }
      ],
      "UpstreamPathTemplate": "/api/{everything}",
      "UpstreamHttpMethod": [ "Get", "Post", "Put", "Delete" ],
      "SwaggerKey": "points"
    },
    // 新增Swagger文件代理路由
    {
      "DownstreamPathTemplate": "/swagger/{everything}",
      "DownstreamScheme": "http",
      "DownstreamHostAndPorts": [
        {
          "Host": "points-service",
          "Port": 5001
        }
      ],
      "UpstreamPathTemplate": "/points/swagger/{everything}",
      "UpstreamHttpMethod": [ "Get" ],
      "SwaggerKey": "points"
    }
  ],
  "GlobalConfiguration": {
    "BaseUrl": "http://gateway-api:5000"
  },
  "SwaggerEndPoints": [
    {
      "Key": "points",
      "Config": [
        {
          "Name": "Points API",
          "Version": "v1",
          // 改为网关代理后的路径
          "Url": "/points/swagger/v1/swagger.json"
        }
      ]
    }
  ]
}

2. 调整中间件执行顺序 #

中间件顺序错误会导致Swagger和Ocelot的逻辑冲突，修改Program.cs的中间件顺序：

using API;
using Confluent.Kafka;
using Ocelot.DependencyInjection;
using Ocelot.Middleware;

var builder = WebApplication.CreateBuilder(args);

var producerConfig = new ProducerConfig();
builder.Configuration.GetSection("Kafka").Bind(producerConfig);
builder.Configuration.AddJsonFile("ocelot.json", true, true);
builder.Services.AddControllers();
builder.Services.AddEndpointsApiExplorer();

builder.Services.AddOcelot(builder.Configuration);
builder.Services.AddSwaggerForOcelot(builder.Configuration);
builder.Services.AddSwaggerGen();

builder.Services.AddSingleton<ProducerConfig>(producerConfig);

var app = builder.Build();
app.UseDeveloperExceptionPage();

// 调整中间件顺序，确保Swagger与Ocelot逻辑正确执行
app.UseSwagger()
   .UseSwaggerForOcelotUI()
   .UseRouting()
   .UseEndpoints(endpoints => 
   {
       endpoints.MapControllers();
   })
   .UseOcelot().Wait();

app.Run();

移除原有的UseSwaggerUI单独配置，统一通过UseSwaggerForOcelotUI访问聚合Swagger界面，地址为http://localhost:52791/swagger

3. 修正Docker环境变量格式 #

docker-compose.yml中的环境变量存在空格、多余逗号的语法错误，会导致ASP.NET Core启动配置异常：

services:
  gateway-api:
    container_name: gateway-api
    ports:
    - "52791:5000"
    build:
      context: .
      dockerfile: API/Dockerfile
    environment:
      - ASPNETCORE_URLS=http://*:5000
      - ASPNETCORE_HTTPS_PORTS=5050
      - ASPNETCORE_HTTP_PORTS=5000
  points-service:
    container_name: points-service
    depends_on:
    - gateway-api 
    ports:
    - "52792:5001"
    environment:
      - ASPNETCORE_URLS=http://*:5001
      - ASPNETCORE_HTTPS_PORTS=5051
      - ASPNETCORE_HTTP_PORTS=5001
    build:
      context: .
      dockerfile: Services/PointsService/PointsService.Api/Dockerfile

4. 验证效果 #

重启所有容器后，访问http://localhost:52791/swagger，即可看到Points API的选项，切换后能正常加载微服务的所有端点。

内容的提问来源于stack exchange，提问作者Faradey Inimicos