ABP VNext 实战指南：动态功能开关（Unleash & LaunchDarkly）

ABP VNext 实战指南：动态功能开关（Unleash & LaunchDarkly）🚀

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✨ TL;DR

• 一次性链式注册，零改动接入 ABP VNext，支持 Unleash 与 LaunchDarkly 双平台 🏃‍♂️
• 自定义 Scoped IFeatureFilter，多租户上下文无缝联动 🌐
• Scrutor 装饰模式本地缓存＋初始化回退策略，确保高性能、高可用 💾🛡️
• 全链路示例：灰度/AB 测试、在线更新、运维 UI、审计、单元 & 集成测试 🛠️

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1. 背景与动机 🎯

在传统 CI/CD 中，「部署即上线」，回滚成本高。功能开关（Feature Flags）让你：

• 小流量灰度发布，安全可控
• AB 测试分流，数据驱动
• 一键回滚，极速下线
• 动态在线更新，无需重启

借助 ABP VNext 模块化与 DI，仅需 1 分钟，即可落地 Unleash（开源）与 LaunchDarkly（商业）双平台接入，并在多租户场景中稳健运行。

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2. 环境与依赖 🛠️

// appsettings.json（共享）
{
  "Unleash": {
    "Url": "https://unleash.{ENV}.mycompany.com/api",
    "ApiKey": "${UNLEASH_API_KEY}"
  },
  "LaunchDarkly": {
    "SdkKey": "${LD_SDK_KEY}"
  }
}

// Program.cs：配置加载
var builder = WebApplication.CreateBuilder(args);
builder.Configuration
       .AddJsonFile("appsettings.json", false, true)
       .AddJsonFile($"appsettings.{
     
     builder.Environment.EnvironmentName}.json", true, true)
       .AddEnvironmentVariables(prefix: "MYAPP_"); // Kubernetes/CI 注入 MYAPP_UNLEASH__APIKEY 等
var appSettings = builder.Configuration;

• 平台：.NET 6 + ABP VNext 6.x

• NuGet 包：

  • Volo.Abp.FeatureManagement、Volo.Abp.AspNetCore.FeatureManagement
  • Microsoft.FeatureManagement、Microsoft.FeatureManagement.AspNetCore
  • Unleash.Client.Extensions (v5+)
  • LaunchDarkly.ServerSdk
  • Scrutor（装饰模式）
  • Testcontainers（集成测试）

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3. 模块声明与服务注册 📦

// MyAbpFeatureModule.cs
using Microsoft.FeatureManagement;
using Unleash;
using LaunchDarkly.Sdk.Server;
using Scrutor;

[DependsOn(
  typeof(AbpFeatureManagementDomainModule),
  typeof(AbpFeatureManagementApplicationModule),
  typeof(AbpFeatureManagementHttpApiModule),
  typeof(AbpAspNetCoreFeatureManagementModule),
  typeof(AbpTenantManagementDomainModule) // 多租户支持
)]
public class MyAbpFeatureModule : AbpModule
{
   
   
  public override void ConfigureServices(ServiceConfigurationContext context)
  {
   
   
    var cfg = context.Services.GetConfiguration();

    // 1. 链式注册 ABP 原生 & 自定义 FeatureFilters
    context.Services.AddFeatureManagement()
      .AddFeatureFilter<PercentageFilter>()
      .AddFeatureFilter<UnleashFeatureFilter>()
      .AddFeatureFilter<LaunchDarklyFeatureFilter>();

    // 2. 注册 Unleash 客户端（单例）+ Scoped Filter
    context.Services.AddUnleash(options =>
    {
   
   
      options.AppName            = "MyAbpApp";
      options.UnleashAPI         = new Uri(cfg["Unleash:Url"]);
      options.CustomHttpHeaders["Authorization"] = cfg["Unleash:ApiKey"];
      options.PollingInterval    = TimeSpan.FromSeconds(15);
    });
    context.Services.AddScoped<UnleashFeatureFilter>();

    // 3. 注册 LaunchDarkly 客户端（单例）+ Scoped Filter
    context.Services.AddLaunchDarklyServer(new SdkOptions
    {
   
   
      SdkKey        = cfg["LaunchDarkly:SdkKey"],
      StartWaitTime = TimeSpan.FromSeconds(5)
    });
    context.Services.AddScoped<LaunchDarklyFeatureFilter>();

    // 4. MVC + [FeatureGate]
    context.Services.AddControllers()
            .AddFeatureManagement();

    // 5. 运维端 UI（可选）
    context.Services.AddFeatureManagementUI();

    // 6. 装饰 IFeatureManager，为 CachedFeatureManager
    context.Services.Decorate<IFeatureManager, CachedFeatureManager>();
  }

  public override void OnApplicationInitialization(ApplicationInitializationContext ctx)
  {
   
   
    var lifetime = ctx.ServiceProvider.GetRequiredService<IHostApplicationLifetime>();
    lifetime.ApplicationStopping.Register(() =>
    {
   
   
      // 优雅释放 SDK
      var unleash = ctx.ServiceProvider.GetService<IUnleash>();
      if (unleash is IUnleash u && u.IsInitialized) u.Dispose();

      var ld = ctx.ServiceProvider.GetService<ILdClient>();
      if (ld is ILdClient l && l.Initialized) l.Dispose();
    });
  }
}

// Program.cs
var builder = WebApplication.CreateBuilder(args);
builder.Host.AddApp<MyAbpFeatureModule>();

var app = builder.Build();
app.InitializeApplication();

app.UseStaticFiles();  // 若启用了 UI 静态资源
app.UseRouting();

app.MapControllers();
app.MapFeatureManagementEndpoints();  // Flag 管理 UI

app.Run();

💡 Tips

• AddEnvironmentVariables(prefix: "MYAPP_") 支持在容器/CI 中注入。
• .Decorate<IFeatureManager, CachedFeatureManager>() 保留原始实现，无递归。
• 确保 UseStaticFiles() 在 UseRouting() 之前配置，才能加载管理 UI 静态资源。