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($"http://{serviceEntity.ConsulIP}:{serviceEntity.ConsulPort}"));//请求注册的Consul地址
var httpCheck = new AgentServiceCheck()
{
DeregisterCriticalServiceAfter=TimeSpan.FromSeconds(),//服务启动多久后注册
Interval=TimeSpan.FromSeconds(),//健康检查时间间隔，或者成为心跳间隔
HTTP=$"http://{serviceEntity.IP}:{serviceEntity.Port}/api/health",//健康检查地址
Timeout=TimeSpan.FromSeconds()
}; //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": "",
"DocName": "Account Service",
"Version": "v1",
"Title": "Account Service API"
},
"Identity": {
"IP": "localhost",
"Port": "",
"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": , // Consul Service Port
"Type": "PollConsul",
"PollingInterval": //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。