Tip: 此篇已加入.NET Core微服務基礎系列文章索引
一、案例結構總覽
這里，假設我們有兩個客戶端（一個Web網站，一個移動App），他們要使用系統，需要通過API網關（這里API網關始終作為客戶端的統一入口）先向IdentityService進行Login以進行驗證並獲取Token，在IdentityService的驗證過程中會訪問數據庫以驗證。然后再帶上Token通過API網關去訪問具體的API Service。這里我們的IdentityService基於IdentityServer4開發，它具有統一登錄驗證和授權的功能。
二、改寫API Gateway
這里主要基於前兩篇已經搭好的API Gateway進行改寫，如不熟悉，可以先瀏覽前兩篇文章：Part 1和Part 2。
2.1 配置文件的改動
...... "AuthenticationOptions": { "AuthenticationProviderKey": "ClientServiceKey", "AllowedScopes": [] } ...... "AuthenticationOptions": { "AuthenticationProviderKey": "ProductServiceKey", "AllowedScopes": [] } ......
上面分別為兩個示例API Service增加Authentication的選項，為其設置ProviderKey。下面會對不同的路由規則設置的ProviderKey設置具體的驗證方式。
2.2 改寫StartUp類
public void ConfigureServices(IServiceCollection services) { // IdentityServer #region IdentityServerAuthenticationOptions => need to refactor Action<IdentityServerAuthenticationOptions> isaOptClient = option => { option.Authority = Configuration["IdentityService:Uri"]; option.ApiName = "clientservice"; option.RequireHttpsMetadata = Convert.ToBoolean(Configuration["IdentityService:UseHttps"]); option.SupportedTokens = SupportedTokens.Both; option.ApiSecret = Configuration["IdentityService:ApiSecrets:clientservice"]; }; Action<IdentityServerAuthenticationOptions> isaOptProduct = option => { option.Authority = Configuration["IdentityService:Uri"]; option.ApiName = "productservice"; option.RequireHttpsMetadata = Convert.ToBoolean(Configuration["IdentityService:UseHttps"]); option.SupportedTokens = SupportedTokens.Both; option.ApiSecret = Configuration["IdentityService:ApiSecrets:productservice"]; }; #endregion services.AddAuthentication() .AddIdentityServerAuthentication("ClientServiceKey", isaOptClient) .AddIdentityServerAuthentication("ProductServiceKey", isaOptProduct); // Ocelot services.AddOcelot(Configuration); ...... }
這里的ApiName主要對應於IdentityService中的ApiResource中定義的ApiName。這里用到的配置文件定義如下：
"IdentityService": { "Uri": "http://localhost:5100", "UseHttps": false, "ApiSecrets": { "clientservice": "clientsecret", "productservice": "productsecret" } }
這里的定義方式，我暫時還沒想好怎么重構，不過肯定是需要重構的，不然這樣一個一個寫比較繁瑣，且不利於配置。
三、新增IdentityService
這里我們會基於之前基於IdentityServer的兩篇文章，新增一個IdentityService，不熟悉的朋友可以先瀏覽一下Part 1和Part 2。
3.1 准備工作
新建一個ASP.NET Core Web API項目，綁定端口5100，NuGet安裝IdentityServer4。配置好證書，並設置其為“較新則復制”，以便能夠在生成目錄中讀取到。
3.2 定義一個InMemoryConfiguration用於測試
/// <summary> /// One In-Memory Configuration for IdentityServer => Just for Demo Use /// </summary> public class InMemoryConfiguration { public static IConfiguration Configuration { get; set; } /// <summary> /// Define which APIs will use this IdentityServer /// </summary> /// <returns></returns> public static IEnumerable<ApiResource> GetApiResources() { return new[] { new ApiResource("clientservice", "CAS Client Service"), new ApiResource("productservice", "CAS Product Service"), new ApiResource("agentservice", "CAS Agent Service") }; } /// <summary> /// Define which Apps will use thie IdentityServer /// </summary> /// <returns></returns> public static IEnumerable<Client> GetClients() { return new[] { new Client { ClientId = "cas.sg.web.nb", ClientName = "CAS NB System MPA Client", ClientSecrets = new [] { new Secret("websecret".Sha256()) }, AllowedGrantTypes = GrantTypes.ResourceOwnerPassword, AllowedScopes = new [] { "clientservice", "productservice", IdentityServerConstants.StandardScopes.OpenId, IdentityServerConstants.StandardScopes.Profile } }, new Client { ClientId = "cas.sg.mobile.nb", ClientName = "CAS NB System Mobile App Client", ClientSecrets = new [] { new Secret("mobilesecret".Sha256()) }, AllowedGrantTypes = GrantTypes.ResourceOwnerPassword, AllowedScopes = new [] { "productservice", IdentityServerConstants.StandardScopes.OpenId, IdentityServerConstants.StandardScopes.Profile } }, new Client { ClientId = "cas.sg.spa.nb", ClientName = "CAS NB System SPA Client", ClientSecrets = new [] { new Secret("spasecret".Sha256()) }, AllowedGrantTypes = GrantTypes.ResourceOwnerPassword, AllowedScopes = new [] { "agentservice", "clientservice", "productservice", IdentityServerConstants.StandardScopes.OpenId, IdentityServerConstants.StandardScopes.Profile } }, new Client { ClientId = "cas.sg.mvc.nb.implicit", ClientName = "CAS NB System MVC App Client", AllowedGrantTypes = GrantTypes.Implicit, RedirectUris = { Configuration["Clients:MvcClient:RedirectUri"] }, PostLogoutRedirectUris = { Configuration["Clients:MvcClient:PostLogoutRedirectUri"] }, AllowedScopes = new [] { IdentityServerConstants.StandardScopes.OpenId, IdentityServerConstants.StandardScopes.Profile, "agentservice", "clientservice", "productservice" }, //AccessTokenLifetime = 3600, // one hour AllowAccessTokensViaBrowser = true // can return access_token to this client } }; } /// <summary> /// Define which IdentityResources will use this IdentityServer /// </summary> /// <returns></returns> public static IEnumerable<IdentityResource> GetIdentityResources() { return new List<IdentityResource> { new IdentityResources.OpenId(), new IdentityResources.Profile(), }; } }
這里使用了上一篇的內容，不再解釋。實際環境中，則應該考慮從NoSQL或數據庫中讀取。
3.3 定義一個ResourceOwnerPasswordValidator
在IdentityServer中，要實現自定義的驗證用戶名和密碼，需要實現一個接口：IResourceOwnerPasswordValidator
public class ResourceOwnerPasswordValidator : IResourceOwnerPasswordValidator { private ILoginUserService loginUserService; public ResourceOwnerPasswordValidator(ILoginUserService _loginUserService) { this.loginUserService = _loginUserService; } public Task ValidateAsync(ResourceOwnerPasswordValidationContext context) { LoginUser loginUser = null; bool isAuthenticated = loginUserService.Authenticate(context.UserName, context.Password, out loginUser); if (!isAuthenticated) { context.Result = new GrantValidationResult(TokenRequestErrors.InvalidGrant, "Invalid client credential"); } else { context.Result = new GrantValidationResult( subject : context.UserName, authenticationMethod : "custom", claims : new Claim[] { new Claim("Name", context.UserName), new Claim("Id", loginUser.Id.ToString()), new Claim("RealName", loginUser.RealName), new Claim("Email", loginUser.Email) } ); } return Task.CompletedTask; } }
這里的ValidateAsync方法中（你也可以把它寫成異步的方式，這里使用的是同步的方式），會調用EF去訪問數據庫進行驗證，數據庫的定義如下（密碼應該做加密，這里只做demo，沒用弄）：
至於EF部分，則是一個典型的簡單的Service調用Repository的邏輯，下面只貼Repository部分：
public class LoginUserRepository : RepositoryBase<LoginUser, IdentityDbContext>, ILoginUserRepository { public LoginUserRepository(IdentityDbContext dbContext) : base(dbContext) { } public LoginUser Authenticate(string _userName, string _userPassword) { var entity = DbContext.LoginUsers.FirstOrDefault(p => p.UserName == _userName && p.Password == _userPassword); return entity; } }
其他具體邏輯請參考示例代碼。
3.4 改寫StarUp類
public void ConfigureServices(IServiceCollection services) { // IoC - DbContext services.AddDbContextPool<IdentityDbContext>( options => options.UseSqlServer(Configuration["DB:Dev"])); // IoC - Service & Repository services.AddScoped<ILoginUserService, LoginUserService>(); services.AddScoped<ILoginUserRepository, LoginUserRepository>(); // IdentityServer4 string basePath = PlatformServices.Default.Application.ApplicationBasePath; InMemoryConfiguration.Configuration = this.Configuration; services.AddIdentityServer() .AddSigningCredential(new X509Certificate2(Path.Combine(basePath, Configuration["Certificates:CerPath"]), Configuration["Certificates:Password"])) //.AddTestUsers(InMemoryConfiguration.GetTestUsers().ToList()) .AddInMemoryIdentityResources(InMemoryConfiguration.GetIdentityResources()) .AddInMemoryApiResources(InMemoryConfiguration.GetApiResources()) .AddInMemoryClients(InMemoryConfiguration.GetClients()) .AddResourceOwnerValidator<ResourceOwnerPasswordValidator>() .AddProfileService<ProfileService>(); ...... }
這里高亮的是新增的部分，為了實現自定義驗證。關於ProfileService的定義如下：
public class ProfileService : IProfileService { public async Task GetProfileDataAsync(ProfileDataRequestContext context) { var claims = context.Subject.Claims.ToList(); context.IssuedClaims = claims.ToList(); } public async Task IsActiveAsync(IsActiveContext context) { context.IsActive = true; } }
3.5 新增統一Login入口
這里新增一個LoginController:
[Produces("application/json")] [Route("api/Login")] public class LoginController : Controller { private IConfiguration configuration; public LoginController(IConfiguration _configuration) { configuration = _configuration; } [HttpPost] public async Task<ActionResult> RequestToken([FromBody]LoginRequestParam model) { Dictionary<string, string> dict = new Dictionary<string, string>(); dict["client_id"] = model.ClientId; dict["client_secret"] = configuration[$"IdentityClients:{model.ClientId}:ClientSecret"]; dict["grant_type"] = configuration[$"IdentityClients:{model.ClientId}:GrantType"]; dict["username"] = model.UserName; dict["password"] = model.Password; using (HttpClient http = new HttpClient()) using (var content = new FormUrlEncodedContent(dict)) { var msg = await http.PostAsync(configuration["IdentityService:TokenUri"], content); if (!msg.IsSuccessStatusCode) { return StatusCode(Convert.ToInt32(msg.StatusCode)); } string result = await msg.Content.ReadAsStringAsync(); return Content(result, "application/json"); } } }
這里假設客戶端會傳遞用戶名，密碼以及客戶端ID(ClientId，比如上面InMemoryConfiguration中的cas.sg.web.nb或cas.sg.mobile.nb)。然后構造參數再調用connect/token接口進行身份驗證和獲取token。這里將client_secret等機密信息封裝到了服務器端，無須客戶端傳遞（對於機密信息一般也不會讓客戶端知道）：
"IdentityClients": { "cas.sg.web.nb": { "ClientSecret": "websecret", "GrantType": "password" }, "cas.sg.mobile.nb": { "ClientSecret": "mobilesecret", "GrantType": "password" } }
3.6 加入API網關中
在API網關的Ocelot配置文件中加入配置，配置如下（這里我是開發用，所以沒有用服務發現，實際環境建議采用服務發現）：
// --> Identity Service Part { "UseServiceDiscovery": false, // do not use Consul service discovery in DEV env "DownstreamPathTemplate": "/api/{url}", "DownstreamScheme": "http", "DownstreamHostAndPorts": [ { "Host": "localhost", "Port": "5100" } ], "ServiceName": "CAS.IdentityService", "LoadBalancerOptions": { "Type": "RoundRobin" }, "UpstreamPathTemplate": "/api/identityservice/{url}", "UpstreamHttpMethod": [ "Get", "Post" ], "RateLimitOptions": { "ClientWhitelist": [ "admin" ], // 白名單 "EnableRateLimiting": true, // 是否啟用限流 "Period": "1m", // 統計時間段：1s, 5m, 1h, 1d "PeriodTimespan": 15, // 多少秒之后客戶端可以重試 "Limit": 10 // 在統計時間段內允許的最大請求數量 }, "QoSOptions": { "ExceptionsAllowedBeforeBreaking": 2, // 允許多少個異常請求 "DurationOfBreak": 5000, // 熔斷的時間，單位為秒 "TimeoutValue": 3000 // 如果下游請求的處理時間超過多少則視如該請求超時 }, "HttpHandlerOptions": { "UseTracing": false // use butterfly to tracing request chain }, "ReRoutesCaseSensitive": false // non case sensitive }
四、改寫業務API Service
4.1 ClientService
（1）安裝IdentityServer4.AccessTokenValidation
NuGet>Install-Package IdentityServer4.AccessTokenValidation
（2）改寫StartUp類
public IServiceProvider ConfigureServices(IServiceCollection services) { ...... // IdentityServer services.AddAuthentication(Configuration["IdentityService:DefaultScheme"]) .AddIdentityServerAuthentication(options => { options.Authority = Configuration["IdentityService:Uri"]; options.RequireHttpsMetadata = Convert.ToBoolean(Configuration["IdentityService:UseHttps"]); }); ...... }
這里配置文件的定義如下：
"IdentityService": { "Uri": "http://localhost:5100", "DefaultScheme": "Bearer", "UseHttps": false, "ApiSecret": "clientsecret" }
4.2 ProductService
與ClientService一致，請參考示例代碼。
五、測試
5.1 測試Client: cas.sg.web.nb
（1）統一驗證&獲取token （by API網關）
（2）訪問clientservice （by API網關）
（3）訪問productservice（by API網關）
5.2 測試Client: cas.sg.mobile.nb
由於在IdentityService中我們定義了一個mobile的客戶端，但是其訪問權限只有productservice，所以我們來測試一下：
（1）統一驗證&獲取token
（2）訪問ProductService（by API網關）
（3）訪問ClientService（by API網關） => 401 Unauthorized
六、小結
本篇主要基於前面Ocelot和IdentityServer的文章的基礎之上，將Ocelot和IdentityServer進行結合，通過建立IdentityService進行統一的身份驗證和授權，最后演示了一個案例以說明如何實現。不過，本篇實現的Demo還存在諸多不足，比如需要重構的代碼較多如網關中各個Api的驗證選項的注冊，沒有對各個請求做用戶角色和權限的驗證等等，相信隨着研究和深入的深入，這些都可以逐步解決。后續會探索一下數據一致性的基本知識以及框架使用，到時再做一些分享。
示例代碼
Click Here => 點我進入GitHub
參考資料
楊中科，《.NET Core微服務介紹課程》
