netcore3.1的网关Ocelot实例

一、创建一个netcore 空项目（APIGateway网关）

添加依赖Install-Package Ocelot ，
若是在16.x之后ReRoutes更改为Routes

1.1 新建configuration.json文件

{
  "ReRoutes": [
    {
      "DownstreamPathTemplate": "/api/customers",
      "DownstreamScheme": "http",
      "DownstreamHostAndPorts": [
        {
          "Host": "localhost",
          "Port": 9003
        }
      ],
      "UpstreamPathTemplate": "/customers",
      "UpstreamHttpMethod": [ "Get" ]
    },
    {
      "DownstreamPathTemplate": "/api/customers/{id}",
      "DownstreamHostAndPorts": [
        {
          "Host": "localhost",
          "Port": 9003
        }
      ],
      "DownstreamPort": 9003,
      "UpstreamPathTemplate": "/customers/{id}",
      "UpstreamHttpMethod": [ "Get" ]
    },
    {
      "DownstreamPathTemplate": "/api/products",
      "DownstreamScheme": "http",
      "DownstreamHostAndPorts": [
        {
          "Host": "localhost",
          "Port": 9002
        }
      ],
      "UpstreamPathTemplate": "/api/products",
      "UpstreamHttpMethod": [ "Get" ]
    }
  ],
  "GlobalConfiguration": {
    "RequestIdKey": "OcRequestId",
    "AdministrationPath": "/administration"
  }
}

1.2.配置pogram文件

using Microsoft.AspNetCore.Hosting;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.Hosting;
using Microsoft.Extensions.Logging;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;

namespace APIGateway
{
    public class Program
    {
        public static void Main(string[] args)
        {
            CreateHostBuilder(args).Build().Run();
        }
        public static IHostBuilder CreateHostBuilder(string[] args) =>
            Host.CreateDefaultBuilder(args)
               .ConfigureAppConfiguration((hostingContext, config) =>
               {
                   //添加配置文件的使用
                   config
                       .SetBasePath(hostingContext.HostingEnvironment.ContentRootPath)
                       .AddJsonFile("configuration.json")
                       .AddEnvironmentVariables();
               })
                .ConfigureWebHostDefaults(webBuilder =>
                {
                    webBuilder.UseStartup<Startup>();
                    webBuilder.UseUrls("http://*:9000");
                });
    }
}

1.3 配置startup

using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.Http;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;
using Ocelot.DependencyInjection;
using Ocelot.Middleware;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;

namespace APIGateway
{
    public class Startup
    {
        // This method gets called by the runtime. Use this method to add services to the container.
        // For more information on how to configure your application, visit https://go.microsoft.com/fwlink/?LinkID=398940
        public void ConfigureServices(IServiceCollection services)
        {
            services.AddOcelot();
            services.AddHttpContextAccessor();
        }

        // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
        public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
        {
            if (env.IsDevelopment())
            {
                app.UseDeveloperExceptionPage();
            }

            app.UseOcelot();
            app.UseRouting();

            app.UseEndpoints(endpoints =>
            {
                endpoints.MapGet("/", async context =>
                {
                    await context.Response.WriteAsync("Hello World!");
                });
            });
        }
    }
}

1.4在launchSettings修改启动端口为9000；

{
  "iisSettings": {
    "windowsAuthentication": false, 
    "anonymousAuthentication": true, 
    "iisExpress": {
      "applicationUrl": "http://localhost:9000",
      "sslPort": 0
    }
  },
  "profiles": {
    "IIS Express": {
      "commandName": "IISExpress",
      "launchBrowser": true,
      "environmentVariables": {
        "ASPNETCORE_ENVIRONMENT": "Development"
      }
    },
    "APIGateway": {
      "commandName": "Project",
      "launchBrowser": true,
      "applicationUrl": "http://localhost:9000",
      "environmentVariables": {
        "ASPNETCORE_ENVIRONMENT": "Development"
      }
    }
  }
}

二、新建webapi项目

2.1 添加控制器

using Microsoft.AspNetCore.Mvc;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;

namespace Microsoft_Server_01.Controllers
{
    [Route("api/[controller]")]
    [ApiController]
    public class CustomersController : ControllerBase
    {
        [HttpGet]
        public IEnumerable<string> Get()
        {
            return new string[] { "values1", "values2" };
        }
        [HttpGet("{id}")]
        public string Get (int id)
        {
            return "value";
        }
    }
}

2.2 修改启动端口为9003

using Microsoft.AspNetCore.Hosting;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.Hosting;
using Microsoft.Extensions.Logging;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;

namespace Microsoft_Server_01
{
    public class Program
    {
        public static void Main(string[] args)
        {
            CreateHostBuilder(args).Build().Run();
        }

        public static IHostBuilder CreateHostBuilder(string[] args) =>
            Host.CreateDefaultBuilder(args)
                .ConfigureWebHostDefaults(webBuilder =>
                {
                    webBuilder.UseStartup<Startup>();
                    webBuilder.UseUrls("http://*:9003");
                });
    }
}

2.3 同上，lunchsetting设置端口为9003

三、启动服务

3.1 运行 weiapi项目，如下成功

3.2 启动网关APIGateway

3.3启动的网关服务，调用的是webapi服务，但实际的请求端口还是9003