1.服务注册
在上一篇的鉴权和登录服务中分别通过NuGet引用Consul这个包，同时新增AppBuilderExtensions类：
???public static class AppBuilderExtensions ???{ ???????public static IApplicationBuilder RegisterConsul(this IApplicationBuilder app,IApplicationLifetime lifetime,ServiceEntity serviceEntity) ???????{ ???????????var consulClient = new ConsulClient(x => x.Address = new Uri($"http://{serviceEntity.ConsulIP}:{serviceEntity.ConsulPort}"));//请求注册的Consul地址 ???????????var httpCheck = new AgentServiceCheck() ???????????{ ???????????????DeregisterCriticalServiceAfter=TimeSpan.FromSeconds(5),//服务启动多久后注册 ???????????????Interval=TimeSpan.FromSeconds(10),//健康检查时间间隔，或者成为心跳间隔 ???????????????HTTP=$"http://{serviceEntity.IP}:{serviceEntity.Port}/api/health",//健康检查地址 ???????????????Timeout=TimeSpan.FromSeconds(5) ???????????}; ???????????//Register service with consul ???????????var registration = new AgentServiceRegistration() ???????????{ ???????????????Checks = new[] {httpCheck}, ???????????????ID=Guid.NewGuid().ToString(), ???????????????Name=serviceEntity.ServiceName, ???????????????Address=serviceEntity.IP, ???????????????Port=serviceEntity.Port, ???????????????Tags = new[] { $"urlprefix-/{serviceEntity.ServiceName}"} //添加urlprefix-/servicename格式的tag标签，以便Fabio识别 ???????????}; ???????????consulClient.Agent.ServiceRegister(registration).Wait();//服务启动时注册，内部实现其实就是使用Consul API进行注册（HttpClient发起) ???????????lifetime.ApplicationStopping.Register(() => ???????????{ ???????????????consulClient.Agent.ServiceDeregister(registration.ID).Wait();//服务停止时取消注册 ???????????}); ???????????return app; ???????} ???} ???public class ServiceEntity ???{ ???????public string IP { get; set; } ???????public int Port { get; set; } ???????public string ServiceName { get; set; } ???????public string ConsulIP { get; set; } ???????public int ConsulPort { get; set; } ???}通过这个类可以提供服务注册的基本参数。
修改Startup启动项中的Configure方法：
public void Configure(IApplicationBuilder app, IHostingEnvironment env, IApplicationLifetime lifetime) ???????{ ???????????if (env.IsDevelopment()) ???????????{ ???????????????app.UseDeveloperExceptionPage(); ???????????} ???????????#region Consul 服务注册 ???????????ServiceEntity serviceEntity = new ServiceEntity ???????????{ ???????????????IP = "127.0.0.1", ??//服务运行地址 ???????????????Port = Convert.ToInt32(Configuration["Consul:ServicePort"]), //服务运行端口 ???????????????ServiceName = Configuration["Consul:Name"], //服务标识,Ocelot中会用到 ???????????????ConsulIP = Configuration["Consul:IP"], //Consul运行地址 ???????????????ConsulPort = Convert.ToInt32(Configuration["Consul:Port"]) ?//Consul运行端口（默认8500） ???????????}; ???????????app.RegisterConsul(lifetime, serviceEntity); ???????????#endregion ???????????app.UseIdentityServer(); ???????????//app.UseAuthentication(); ???????????app.UseStaticFiles(); ???????????app.UseMvcWithDefaultRoute(); ???????}看下配置文件需要新增的东西：
{ ?"Service": { ???"Name": "MI.Service", ???"Port": "7001", ???"DocName": "Account Service", ???"Version": "v1", ???"Title": "Account Service API" ?}, ?"Identity": { ???"IP": "localhost", ???"Port": "7000", ???"Scheme": "Bearer" ?}, ?"ConnectionStrings": { ???"SqlConnection": "server=.;uid=sa;pwd=sa;database=MI" ?}, ?"Consul": { ???"Name": "MI.Service.Account", ???"ServiceProt": "7001", ???"IP": "localhost", ???"Port": "8500" ?}}蓝色标识的Consul部分是我们这里需要用到的，这里我把项目名称当作服务注册标识。
然后还需要为两个服务添加两个方法，一个是用来做健康检查的，一个是用来测试的：
???[Route("api/Health")] ???public class HealthController : Controller ???{ ???????[HttpGet] ???????public IActionResult Get() => Ok("ok"); ???}public class MiUserController : Controller ???{ ???????public MIContext _context; ???????public MiUserController(MIContext _context) ???????{ ???????????this._context = _context; ???????} ???????public string Index() ???????{ ???????????return "Successful"; ???????} ???????。。。。。。}通过“consul agent -dev”命令运行Consul，访问127.0.0.1：8500我们可以看到Consul的UI界面：
这里可以看到我们已经注册的两个服务。
2.服务发现
新建API项目MI.Ocelot，通过NuGet引用Ocelot和Ocelot.Provider.Consul两个包，并修改启动项注册Ocelot和Consul：
public void ConfigureServices(IServiceCollection services) ???????{ ???????????//services.AddMvc(); ???????????services.AddOcelot(Configuration) ???????????????.AddConsul(); ???????} ???????// This method gets called by the runtime. Use this method to configure the HTTP request pipeline. ???????public void Configure(IApplicationBuilder app, IHostingEnvironment env) ???????{ ???????????if (env.IsDevelopment()) ???????????{ ???????????????app.UseDeveloperExceptionPage(); ???????????} ???????????app.UseOcelot(); ???????????//app.UseMvc(); ?????????}然后添加配置文件consul.json:
{ ?"ReRoutes": [ ???{ ?????"UseServiceDiscovery": true, //启用服务发现 ?????"DownstreamPathTemplate": "/Account/{url}", //下游转发路由 ?????"DownstreamScheme": "http", //标识头 ?????"ServiceName": "MI.Service.Account", //服务注册标识 ?????"LoadBalancer": "RoundRobin", //服务均衡：轮询 ?????"UpstreamPathTemplate": "/Account/{url}", //上游请求路由 ?????"UpstreamHttpMethod": [ "Get", "Post" ], //请求的方法类型 ?????"ReRoutesCaseSensitive": false //不区分大小写 ???}, ???{ ?????"UseServiceDiscovery": true, ?????"DownstreamPathTemplate": "/Identity/{url}", ?????"DownstreamScheme": "http", ?????"ServiceName": "MI.Service.IdentityServer", ?????"LoadBalancer": "RoundRobin", ?????"UpstreamPathTemplate": "/Identity/{url}", ?????"UpstreamHttpMethod": [ "Get", "Post" ], ?????"ReRoutesCaseSensitive": false ???} ?], ?"GlobalConfiguration": { ???//"BaseUrl": "http://localhost:7003", ???"ServiceDiscoveryProvider": { ?????"Host": "127.0.0.1", // Consul Service IP ?????"Port": 8500, // Consul Service Port ?????"Type": "PollConsul", ?????"PollingInterval": 100 //健康检查时间端 ???} ?}}在Program中启用这个配置文件：
???????public static IWebHost BuildWebHost(string[] args) => ???????????WebHost.CreateDefaultBuilder(args) ???????????????.UseStartup<Startup>() ???????????????.ConfigureAppConfiguration((hostingContext,builder)=> { ???????????????????builder.AddJsonFile("consul.json"); ???????????????}) ???????????????.Build();到此，网关配置完毕。现在我将网关项目MI.Gateway部署在7003端口，登录服务MI.Service.Account部署在7001端口，鉴权服务部署在7000端口，我会通过访问网关服务来请求登录服务：
这里的流程是这样的，Ocelot通过“/Account/MiUser/Index”匹配到了“/Account/{url}”这个路由，进而拿到了“MI.Service.Account”这个服务注册标识，然后通过Consul拿到了对应的地址，并转发了请求，同时返回结果。
到此，具备服务注册和发现的简单网关服务就搭建完毕了，后面有时间会继续优化，添加限流、熔断，同时身份验证会在Ocelot中进行，而不是再去访问单独的鉴权服务。
.Net Core 商城微服务项目系列（二）：使用Ocelot + Consul构建具备服务注册和发现功能的网关
原文地址：https://www.cnblogs.com/weiBlog/p/9833807.html