Tip: 此篇已加入.NET Core微服务基础系列文章索引
一、案例结构总览
这里，假设我们有两个客户端（一个Web网站，一个移动App），他们要使用系统，需要通过API网关（这里API网关始终作为客户端的统一入口）先向IdentityService进行Login以进行验证并获取Token，在IdentityService的验证过程中会访问数据库以验证。然后再带上Token通过API网关去访问具体的API Service。这里我们的IdentityService基于IdentityServer4开发，它具有统一登录验证和授权的功能。
二、改写API Gateway
这里主要基于前两篇已经搭好的API Gateway进行改写，如不熟悉，可以先浏览前两篇文章：Part 1和Part 2。
2.1 配置文件的改动
......
"AuthenticationOptions": {
"AuthenticationProviderKey": "ClientServiceKey",
"AllowedScopes": []
}
......
"AuthenticationOptions": {
"AuthenticationProviderKey": "ProductServiceKey",
"AllowedScopes": []
}
...... 上面分别为两个示例API Service增加Authentication的选项，为其设置ProviderKey。下面会对不同的路由规则设置的ProviderKey设置具体的验证方式。
2.2 改写StartUp类
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);
......
}这里的ApiName主要对应于IdentityService中的ApiResource中定义的ApiName。这里用到的配置文件定义如下：
"IdentityService": {
"Uri": "http://localhost:5100",
"UseHttps": false,
"ApiSecrets": {
"clientservice": "clientsecret",
"productservice": "productsecret"
}
}这里的定义方式，我暂时还没想好怎么重构，不过肯定是需要重构的，不然这样一个一个写比较繁琐，且不利于配置。
三、新增IdentityService
这里我们会基于之前基于IdentityServer的两篇文章，新增一个IdentityService，不熟悉的朋友可以先浏览一下Part 1和Part 2。
3.1 准备工作
新建一个ASP.NET Core Web API项目，绑定端口5100，NuGet安装IdentityServer4。配置好证书，并设置其为“较新则复制”，以便能够在生成目录中读取到。
3.2 定义一个InMemoryConfiguration用于测试
/// <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(),
};
}
}这里使用了上一篇的内容，不再解释。实际环境中，则应该考虑从NoSQL或数据库中读取。
3.3 定义一个ResourceOwnerPasswordValidator
在IdentityServer中，要实现自定义的验证用户名和密码，需要实现一个接口：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;
}
}这里的ValidateAsync方法中（你也可以把它写成异步的方式，这里使用的是同步的方式），会调用EF去访问数据库进行验证，数据库的定义如下（密码应该做加密，这里只做demo，没用弄）：
至于EF部分，则是一个典型的简单的Service调用Repository的逻辑，下面只贴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;
}
}其他具体逻辑请参考示例代码。
3.4 改写StarUp类
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>();
......
}这里高亮的是新增的部分，为了实现自定义验证。关于ProfileService的定义如下：
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 新增统一Login入口
这里新增一个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");
}
}
}这里假设客户端会传递用户名，密码以及客户端ID(ClientId，比如上面InMemoryConfiguration中的cas.sg.web.nb或cas.sg.mobile.nb)。然后构造参数再调用connect/token接口进行身份验证和获取token。这里将client_secret等机密信息封装到了服务器端，无须客户端传递（对于机密信息一般也不会让客户端知道）：
"IdentityClients": {
"cas.sg.web.nb": {
"ClientSecret": "websecret",
"GrantType": "password"
},
"cas.sg.mobile.nb": {
"ClientSecret": "mobilesecret",
"GrantType": "password"
}
}3.6 加入API网关中
在API网关的Ocelot配置文件中加入配置，配置如下（这里我是开发用，所以没有用服务发现，实际环境建议采用服务发现）：
// --> 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" ], // 白名单
"EnableRateLimiting": true, // 是否启用限流
"Period": "1m", // 统计时间段：1s, 5m, 1h, 1d
"PeriodTimespan": 15, // 多少秒之后客户端可以重试
"Limit": 10 // 在统计时间段内允许的最大请求数量
},
"QoSOptions": {
"ExceptionsAllowedBeforeBreaking": 2, // 允许多少个异常请求
"DurationOfBreak": 5000, // 熔断的时间，单位为秒
"TimeoutValue": 3000 // 如果下游请求的处理时间超过多少则视如该请求超时
},
"HttpHandlerOptions": {
"UseTracing": false // use butterfly to tracing request chain
},
"ReRoutesCaseSensitive": false // non case sensitive
}四、改写业务API Service
4.1 ClientService
（1）安装IdentityServer4.AccessTokenValidation
NuGet>Install-Package IdentityServer4.AccessTokenValidation
（2）改写StartUp类
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"]);
});
......
}这里配置文件的定义如下：
"IdentityService": {
"Uri": "http://localhost:5100",
"DefaultScheme": "Bearer",
"UseHttps": false,
"ApiSecret": "clientsecret"
}4.2 ProductService
与ClientService一致，请参考示例代码。
五、测试
5.1 测试Client: cas.sg.web.nb
（1）统一验证&获取token （by API网关）
（2）访问clientservice （by API网关）
（3）访问productservice（by API网关）
5.2 测试Client: cas.sg.mobile.nb
由于在IdentityService中我们定义了一个mobile的客户端，但是其访问权限只有productservice，所以我们来测试一下：
（1）统一验证&获取token
（2）访问ProductService（by API网关）
（3）访问ClientService（by API网关） => 401 Unauthorized
六、小结
本篇主要基于前面Ocelot和IdentityServer的文章的基础之上，将Ocelot和IdentityServer进行结合，通过建立IdentityService进行统一的身份验证和授权，最后演示了一个案例以说明如何实现。不过，本篇实现的Demo还存在诸多不足，比如需要重构的代码较多如网关中各个Api的验证选项的注册，没有对各个请求做用户角色和权限的验证等等，相信随着研究和深入的深入，这些都可以逐步解决。后续会探索一下数据一致性的基本知识以及框架使用，到时再做一些分享。
示例代码
Click Here => 点我进入GitHub
参考资料
杨中科，《.NET Core微服务介绍课程》
作者：周旭龙
出处：http://edisonchou.cnblogs.com
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