初探基于Asp.Net Core 3.1的Ocelot网关

环境Asp.Net Core 3.1

一：搭建ApiGateway

　　1：新建一个NetCore项目

　　　　引入Ocelot包

　　　　Install-Package Ocelot

　　2：添加Ocelot的配置文件,我命名为Config.json

　　Ocelot的配置文件一定要根据NetCore的版本来配置，netCore1.0 、2.0、3.0+都有一些不同，建议参考官网配置

{
  "Routes": [
    {
      "DownstreamPathTemplate": "/{url}",
      "UpstreamPathTemplate": "/{url}",
      "UpstreamHttpMethod": [
        "Get"
      ],
      "DownstreamHttpMethod": "Get",
      "DownstreamHttpVersion": "",
      "AddHeadersToRequest": {},
      "AddClaimsToRequest": {},
      // 授权 身份验证
      "RouteClaimsRequirement": {
        //  "UserType":"registered"
      },
      "AddQueriesToRequest": {},
      "RequestIdKey": "",
      "FileCacheOptions": {
        "TtlSeconds": 0,
        "Region": ""
      },
      "RouteIsCaseSensitive": false,
      "ServiceName": "",
      "DownstreamScheme": "http",
      "DownstreamHostAndPorts": [
        {
          "Host": "localhost",
          "Port": 8081
        },
        {
          "Host": "localhost",
          "Port": 8082
        }
      ],
      "QoSOptions": {
        "ExceptionsAllowedBeforeBreaking": 0,
        "DurationOfBreak": 0,
        "TimeoutValue": 0
      },
      //负载均衡算法
      // LeastConnection:请求最空闲的服务器
      // RoundRobin：轮流
      // NoLoadBalance:总是发往第一个请求或者是服务发现
      "LoadBalancerOptions": {
        "Type": "LeastConnection"
      },
      "RateLimitOptions": {
        "ClientWhitelist": [],
        "EnableRateLimiting": false,
        "Period": "",
        "PeriodTimespan": 0,
        "Limit": 0
      },
      "AuthenticationOptions": {
        "AuthenticationProviderKey": "",
        "AllowedScopes": []
      },
      "HttpHandlerOptions": {
        "AllowAutoRedirect": true,
        "UseCookieContainer": true,
        "UseTracing": true,
        "MaxConnectionsPerServer": 100
      },
      "DangerousAcceptAnyServerCertificateValidator": false
    }
  ],
  "GlobalConfiguration": {
    //外部暴露的Url
    "BaseUrl": "http://localhost:8080",
    //限流扩展配置
    "RateLimitOptions": {
      //Http头  X-Rate-Limit 和 Retry-After 是否禁用
      "DisableRateLimitHeaders": false,
      //当请求过载被截断时返回的消息
      "QuotaExceededMessage": "请求超出最大限制！",
      //当请求过载被截断时返回的http status
      "HttpStatusCode": 999,
      //用来识别客户端的请求头，默认是 ClientId
      "ClientIdHeader": "ClientId"
    }
  }
}

　　

　　3：配置Program

　　

 public static IHostBuilder CreateHostBuilder(string[] args) =>
            Host.CreateDefaultBuilder(args)
                .ConfigureWebHostDefaults(webBuilder =>
                {
                    webBuilder.UseStartup<Startup>();
                })
            .ConfigureAppConfiguration((hostingContext,config)=> {
                config.SetBasePath(hostingContext.HostingEnvironment.ContentRootPath)
                .AddJsonFile("Config.json", true, true)
                .AddEnvironmentVariables();
            });

 

　　4:　　配置Startup

public class Startup
    {
        public IConfiguration Configuration { get; }
        public Startup(IConfiguration configuration)
        {
            Configuration = configuration;
        }
        // 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(Configuration);
        }

        // 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().Wait();
        }
    }

　　

5:创建两个webApi项目

Service001:  将端口设置为8081

[Route("/[controller]")]
    [ApiController]
    public class HomeController : ControllerBase
    {
        [HttpGet]
        public string GetUser()
        {
             return string.Format("Service001 {0}", DateTime.Now);
        }
    }

　Service002:将端口设置为8082

[Route("/[controller]")]
    [ApiController]
    public class HomeController : ControllerBase
    {
        [HttpGet]
        public string GetUser()
        {
            return string.Format("Service002 {0}", DateTime.Now);
        }
    }

　　

运行看结果：