NET Core + Ocelot + IdentityServer4 + Consul .NET Core + Ocelot + IdentityServer4 + Consul 基础架构实现

先决条件

关于 Ocelot
- 针对使用 .NET 开发微服务架构或者面向服务架构提供一个统一访问系统的组件。参考
- 本文将使用 Ocelot 构建统一入口的 Gateway。
关于 IdentityServer4
- IdentityServer4 是一个 OpenID Connect 和 OAuth 2.0 框架用于 ASP.NET Core 。IdentityServer4 在你的应用程序中集成了基于令牌认证、单点登录、API访问控制所需的所有协议和扩展点。参考
- 本文将使用 IdentityServer4 搭建独立认证服务器。
关于 Consul
- Consul 是一个服务网格解决方案，通过服务发现、配置、功能分割提供一个全功能的控制层。这些功能可以单独使用，也可以同时使用以形成一个完整的网格服务。参考
- 本文将使用 Consul 注册多个服务。
关于 .Net Core
- 将使用 WebApi 构建多个服务

构建 IdentityServer 服务

添加 ASP.Net Core Web 项目
添加空项目
在程序包管理控制台中输入：Install-Package IdentityServer4.AspNetIdentity

添加 Config.cs 文件，并添加内容如下：

 using System.Collections.Generic;
 using IdentityServer4.Models;
 using IdentityServer4.Test;

 namespace IdentityServer
 {
     public sealed class Config
     {
         public static IEnumerable<ApiResource> GetApiResources()
         {
             return new List<ApiResource>
             {
                 new ApiResource("ServiceA", "ServiceA API"),
                 new ApiResource("ServiceB", "ServiceB API")
             };
         }

         public static IEnumerable<Client> GetClients()
         {
             return new List<Client>
             {
                 new Client
                 {
                     ClientId = "ServiceAClient",
                     AllowedGrantTypes = GrantTypes.ResourceOwnerPassword,
                     ClientSecrets =
                     {
                         new Secret("ServiceAClient".Sha256())
                     },
                     AllowedScopes = new List<string> {"ServiceA"},
                     AccessTokenLifetime = 60 * 60 * 1
                 },
                 new Client
                 {
                     ClientId = "ServiceBClient",
                     AllowedGrantTypes = GrantTypes.ResourceOwnerPassword,
                     ClientSecrets =
                     {
                         new Secret("ServiceBClient".Sha256())
                     },
                     AllowedScopes = new List<string> {"ServiceB"},
                     AccessTokenLifetime = 60 * 60 * 1
                 }
             };
         }

         public static List<TestUser> GetUsers()
         {
             return new List<TestUser>
             {
                 new TestUser
                 {
                     Username = "test",
                     Password = "123456",
                     SubjectId = "1"
                 }
             };
         }

         public static IEnumerable<IdentityResource> GetIdentityResources()
         {
             return new List<IdentityResource>();
         }
     }
 }

注意：这里添加了两个 Client ，分别为 ServiceA、ServiceB ，因此接下来将构建这两个服务。

删掉StartUp.cs文件，在Program.cs中添加内容如下：

 using Microsoft.AspNetCore;
 using Microsoft.AspNetCore.Builder;
 using Microsoft.AspNetCore.Hosting;
 using Microsoft.AspNetCore.Mvc;
 using Microsoft.Extensions.DependencyInjection;

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

         public static IWebHostBuilder CreateWebHostBuilder(string[] args)
         {
             return WebHost.CreateDefaultBuilder(args).ConfigureServices(services =>
             {
                 services.AddMvc().SetCompatibilityVersion(CompatibilityVersion.Version_2_2);

                 services.AddIdentityServer()
                     .AddDeveloperSigningCredential()
                     .AddInMemoryIdentityResources(Config.GetIdentityResources())
                     .AddInMemoryApiResources(Config.GetApiResources())
                     .AddInMemoryClients(Config.GetClients())
                     .AddTestUsers(Config.GetUsers());
             }).Configure(app =>
             {
                 app.UseIdentityServer();
             });
         }
     }
 }

注意：AddDeveloperSigningCredential() 方法用于添加开发时使用的 Key material ，生产环境中不要使用该方法。在 .NET Core 2.2 中新建的 Web 项目文件 csproj 中包含了如下内容：
csharp <PropertyGroup> <TargetFramework>netcoreapp2.2</TargetFramework> <AspNetCoreHostingModel>InProcess</AspNetCoreHostingModel> </PropertyGroup>
这里更改
csharp <AspNetCoreHostingModel>InProcess</AspNetCoreHostingModel>
为或直接删除该行，这么做的原因是当值为 InProcess 时，读写 tempkey.rsa 将产生权限问题。关于 AspNetCoreHostingModel 可参考 ASP.NET Core Module 。
csharp <AspNetCoreHostingModel>OutOfProcess</AspNetCoreHostingModel>

F5 启动该服务，显示如下：

在浏览器中输入 http://localhost:38033/.well-known/openid-configuration ，得到以下内容

至此，一个包含两个服务认证的认证服务搭建完毕。

构建 ServiceA、ServiceB

添加 ASP.Net Core Web 项目，这里以 ServiceA 为例进行构建
添加 ASP.Net Core API

在 StartUp.cs 中添加内容如下：

 using Microsoft.AspNetCore.Builder;
 using Microsoft.AspNetCore.Hosting;
 using Microsoft.AspNetCore.Mvc;
 using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.DependencyInjection;

 namespace ServiceA
 {
     public class Startup
     {
         public Startup(IConfiguration configuration)
         {
             Configuration = configuration;
         }

         public IConfiguration Configuration { get; }

         // This method gets called by the runtime. Use this method to add services to the container.
         public void ConfigureServices(IServiceCollection services)
         {
             services.AddMvc().SetCompatibilityVersion(CompatibilityVersion.Version_2_2);

             services.AddAuthentication("Bearer")
                 .AddJwtBearer("Bearer", options =>
                 {
                     options.Authority = "http://127.0.0.1:8021";
                     options.RequireHttpsMetadata = false;
                     options.Audience = "ServiceA";
                 });
         }

         // 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.UseAuthentication();
             app.UseMvc();
         }
     }
 }

添加 SessionController 用于用户登录，内容如下：

 using System.ComponentModel.DataAnnotations;
 using System.Net.Http;
 using System.Threading.Tasks;
 using IdentityModel.Client;
 using Microsoft.AspNetCore.Mvc;

 namespace ServiceA.Controllers
 {
     [Route("api/[controller]")]
     [ApiController]
     public class SessionController : ControllerBase
     {
         public async Task<string> Login(UserRequestModel userRequestModel)
         {
             // discover endpoints from metadata
             var client = new HttpClient();
             DiscoveryResponse disco = await client.GetDiscoveryDocumentAsync("http://127.0.0.1:8021");
             if (disco.IsError)
             {
                 return "认证服务器未启动";
             }
             TokenResponse tokenResponse = await client.RequestPasswordTokenAsync(new PasswordTokenRequest
             {
                 Address = disco.TokenEndpoint,
                 ClientId = "ServiceAClient",
                 ClientSecret = "ServiceAClient",
                 UserName = userRequestModel.Name,
                 Password = userRequestModel.Password
             });

             return tokenResponse.IsError ? tokenResponse.Error : tokenResponse.AccessToken;
         }
     }

     public class UserRequestModel
     {
         [Required(ErrorMessage = "用户名称不可以为空")]
         public string Name { get; set; }

         [Required(ErrorMessage = "用户密码不可以为空")]
         public string Password { get; set; }
     }
 }

添加 HealthController 用于 Consul 进行服务健康检查，内容如下：

 using Microsoft.AspNetCore.Mvc;

 namespace ServiceA.Controllers
 {
     [Route("api/[controller]"), ApiController]
     public class HealthController : ControllerBase
     {
         /// <summary>
         /// 健康检查
         /// </summary>
         /// <returns></returns>
         [HttpGet]
         public IActionResult Get()
         {
             return Ok();
         }
     }
 }

更改 ValuesController.cs 内容如下：

 using System.Collections.Generic;
 using Microsoft.AspNetCore.Authorization;
 using Microsoft.AspNetCore.Mvc;

 namespace ServiceA.Controllers
 {
     [Authorize] //添加 Authorize Attribute 以使该控制器启用认证
     [Route("api/[controller]")]
     [ApiController]
     public class ValuesController : ControllerBase
     {
         // GET api/values
         [HttpGet]
         public ActionResult<IEnumerable<string>> Get()
         {
             return new[] { "value1", "value2" };
         }
     }
 }

注意，以上基本完成了 ServiceA 的服务构建，但在实际应用中应做一些修改，例如：IdentityServer 地址应在 appsettings.json 中进行配置，不应把地址分散于项目中各处；认证服务启用最好在全局启用，以防止漏写等等。ServiceB 的内容与 ServiceA 大致相似，因此文章中将不再展示 ServiceB 的构建过程。

Gateway 构建

添加ASP.Net Web
添加空项目
打开程序包管理器控制台输入命令：
csharp install-package Ocelot //添加 Ocelot
csharp install-package Ocelot.Provider.Consul // 添加 Consul 服务发现

添加 ocelot.json 文件，内容如下

 {
 "ReRoutes": [
     {
     "DownstreamPathTemplate": "/api/{everything}",
     "DownstreamScheme": "http",
     "UpstreamPathTemplate": "/ServiceA/{everything}",
     "UpstreamHttpMethod": [ "GET", "POST", "DELETE", "PUT" ],
     "ServiceName": "ServiceA", //consul 服务中 ServiceA 的名称
     "LoadBalancerOptions": {
         "Type": "LeastConnection"
     }
     },
     {
     "DownstreamPathTemplate": "/api/{everything}",
     "DownstreamScheme": "http",
     "UpstreamPathTemplate": "/ServiceB/{everything}",
     "UpstreamHttpMethod": [ "GET", "POST", "DELETE", "PUT" ],
     "ServiceName": "ServiceB", //consul 服务中 ServiceB 的名称
     "LoadBalancerOptions": {
         "Type": "LeastConnection"
     }
     }
 ],
 "GlobalConfiguration": {
     "ServiceDiscoveryProvider": {    // Consul 服务发现配置
     "Host": "localhost",    // Consul 地址
     "Port": 8500,
     "Type": "Consul"
     }
 }
 }

删除 StartUp.cs 文件，在 Program.cs 文件中添加如下内容

 using System.IO;
 using Microsoft.AspNetCore.Hosting;
 using Microsoft.Extensions.Configuration;
 using Ocelot.DependencyInjection;
 using Ocelot.Middleware;
 using Ocelot.Provider.Consul;

 namespace ApiGateway
 {
     public class Program
     {
         public static void Main(string[] args)
         {
             new WebHostBuilder()
                 .UseKestrel()
                 .UseContentRoot(Directory.GetCurrentDirectory())
                 .ConfigureAppConfiguration((hostingContext, config) =>
                 {
                     config
                         .SetBasePath(hostingContext.HostingEnvironment.ContentRootPath)
                         .AddJsonFile("appsettings.json", true, true)
                         .AddJsonFile($"appsettings.{hostingContext.HostingEnvironment.EnvironmentName}.json", true, true)
                         .AddJsonFile("ocelot.json")
                         .AddEnvironmentVariables();
                 })
                 .ConfigureServices(services =>
                 {
                     services.AddOcelot().AddConsul();
                 })
                 .ConfigureLogging((hostingContext, logging) =>
                 {
                     //add your logging
                 })
                 .UseIISIntegration()
                 .Configure(app =>
                 {
                     app.UseOcelot().Wait();
                 })
                 .Build()
                 .Run();
         }
     }
 }

注意：打开 Gateway.csproj 文件，更改

<PropertyGroup>
    <TargetFramework>netcoreapp2.2</TargetFramework>
    <AspNetCoreHostingModel>InProcess</AspNetCoreHostingModel>
</PropertyGroup>

为

<PropertyGroup>
    <TargetFramework>netcoreapp2.2</TargetFramework>
    <AspNetCoreHostingModel>OutOfProcess</AspNetCoreHostingModel>
</PropertyGroup>

至此，一个基础网关基本构建完成。

构建 Consul 服务

使用 Chocoletey 安装 Consul，
```
choco install consul
```
新建一个文件夹以保存 Consul 服务配置

在 consul.d 文件夹中添加配置文件，内容如下:

    {
        "services": [{
                "ID": "ServiceA",
                "Name": "ServiceA",
                "Tags": [
                    "ServiceAWebApi", "Api"
                ],
                "Address": "127.0.0.1",
                "Port": 8010,
                "Check": {
                    "HTTP": "http://127.0.0.1:8010/Api/health",
                    "Interval": "10s"
                }
            }, {
                "id": "ServiceB",
                "name": "ServiceB",
                "tags": [
                    "ServiceBWebApi","Api"
                ],
                "Address": "127.0.0.1",
                "Port": 8011,
                "Check": [{
                        "HTTP": "http://127.0.0.1:8011/Api/health",
                        "Interval": "10s"
                    }
                ]
            }
        ]
    }