c# - NServiceBus IUniformSession 不适用于 Azure WebJobs SDK

Question

我在使用通用主机让 IUniformSession 在 Azure WebJobs SDK 项目中工作时遇到问题。我正在使用 .NET 内置 DI。我创建了一个紧凑的复制品，如下所示。

我正在使用

• NServiceBus 7.7.4
• NServiceBus.Extensions.Hosting 1.1.0
• NServiceBus.UniformSession 2.2.0
• Microsoft.Azure.WebJobs 3.0.33
• .NET 6

预期行为

当类(“作业”)实例化时，IUniformSession 被解析为依赖项。

实际行为

IUniformSession 始终解析为 NULL。一些快速断言(如下所示)表明 IUniformSession 已在 DI 容器中注册，因此 .EnableUniformSession() 正确执行此操作，但当请求实例时，它始终解析为 NULL。

重现步骤

csproj

<ItemGroup>
    <PackageReference Include="Microsoft.Azure.WebJobs" Version="3.0.33" />
    <PackageReference Include="Microsoft.Azure.WebJobs.Extensions" Version="4.0.1" />
    <PackageReference Include="Microsoft.Azure.WebJobs.Extensions.Storage" Version="5.0.1" />
    <PackageReference Include="Microsoft.Azure.WebJobs.Host.Storage" Version="4.1.0" />
    <PackageReference Include="Microsoft.Extensions.Configuration" Version="6.0.1" />
    <PackageReference Include="NServiceBus" Version="7.7.4" />
    <PackageReference Include="NServiceBus.Extensions.Hosting" Version="1.1.0" />
    <PackageReference Include="NServiceBus.UniformSession" Version="2.2.0" />
    <PackageReference Include="Serilog" Version="2.11.0" />
    <PackageReference Include="Serilog.Extensions.Hosting" Version="5.0.1" />
    <PackageReference Include="Serilog.Sinks.Console" Version="4.0.1" />
  </ItemGroup>

程序.cs

using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;
using NServiceBus;
using NServiceBus.UniformSession;
using NSUniformSessionRepro.DemoClasses;
using Serilog;

// Setup the ability to read config files
var configurationBuilder = new ConfigurationBuilder()
     .SetBasePath(Directory.GetCurrentDirectory())
     // then read the environment variables (in Azure) which will override some settings from the local settings
     .AddEnvironmentVariables();
var configuration = configurationBuilder.Build();

var builder = new HostBuilder();
builder
    .UseSerilog(Log.Logger)
    .ConfigureAppConfiguration((context, config) =>
    {
        config.AddConfiguration(configuration);
    })
    .ConfigureWebJobs(b =>
    {
        b.AddAzureStorageCoreServices()
        .AddAzureStorageBlobs()
        .AddAzureStorageQueues()
        .AddTimers();
    });

IServiceCollection _serviceCollection = null;

builder.ConfigureServices(services =>
{
    services.AddTransient<IMessagingService, MessagingService>();
    _serviceCollection = services;
    
});

builder.UseNServiceBus(context =>
{
    var endpointConfiguration = new EndpointConfiguration("MyEndpoint");

    endpointConfiguration.EnableUniformSession();
    endpointConfiguration.UseTransport<LearningTransport>();
    endpointConfiguration.UsePersistence<LearningPersistence>();
    // configure endpoint here
    return endpointConfiguration;
});


var host = builder.Build();

var isUniformSessionRegistered = _serviceCollection.Any(x => x.ServiceType == typeof(IUniformSession));
Console.WriteLine("UniformSession is registered in DI: " + isUniformSessionRegistered);

using (host)
{
    await host.RunAsync();
}



static void ConfigureLogging(IConfigurationRoot configuration)
{
    var loggerConfiguration = new LoggerConfiguration()
        .MinimumLevel.Information()
        .WriteTo.Console();

    Log.Logger = loggerConfiguration
        .CreateLogger();
}

MessagingService.cs(只是一个虚拟类，其本身依赖于 IUniformSession)

public interface IMessagingService
    {
        // public for testing
        IUniformSession UniformSession { get; set; }
        Task Send(object message);
    }

    public class MessagingService : IMessagingService
    {
        // public for testing
        public IUniformSession UniformSession { get; set; }

        public MessagingService(IUniformSession uniformSession)
        {
            UniformSession = uniformSession;
        }

        public async Task Send(object message)
            => await UniformSession.Send(message);
    }

演示作业

public class DemoJob
    {
        private readonly IMessagingService _messagingService;

        public DemoJob(IMessagingService messagingService)
        {
            _messagingService = messagingService;
        }

        public void DummyJob([TimerTrigger("0 0 12 * * *", RunOnStartup = true, UseMonitor = false)] TimerInfo timer, TextWriter log)
        {
            // no-op
            // for testing puporses
            if (_messagingService.UniformSession == null)
                Console.Write("UniformSession was NULL");
        }
    }

任何帮助将不胜感激。

Answer 1

这有点棘手，因为主机的设置方式会因启动顺序而导致一些问题。

首先，我不确定你为什么要在 IUniformSession 上构建自己的抽象。通过IMessagingService所以我就不提这个了。请记住IUniformSession已经是 IMessageSession 的抽象(这就是你所需要的)和 IMessageHandlerContext .

您应该能够依赖 IUniformSession或IMessageSession将调用移至 builder.UseNServiceBus在调用 builder.ConfigureWebJobs 之前，例如:

builder
    .UseSerilog(Log.Logger)
    .ConfigureAppConfiguration((context, config) =>
    {
        config.AddConfiguration(configuration);
    })
    .UseNServiceBus(context =>
    {
        var endpointConfiguration = new EndpointConfiguration("MyEndpoint");

        endpointConfiguration.EnableUniformSession();
        endpointConfiguration.UseTransport<LearningTransport>();
        endpointConfiguration.UsePersistence<LearningPersistence>();
        // configure endpoint here
        return endpointConfiguration;
    })
    .ConfigureWebJobs(b =>
    {
        b.AddAzureStorageCoreServices()
        .AddAzureStorageBlobs()
        .AddAzureStorageQueues()
        .AddTimers();
    });

这将确保 NServiceBus 在 Web 作业相关代码之前配置并启动，以便可以在正确的时间点通过 DI 注入(inject)所需的服务。

请注意，使用IMessageSession应该早点指出这一点，因为 NServiceBus 通用主机支持有 explicit code to detect such ordering issues统一 session 没有。