docker - 使用 TopShelf 的 .net core 控制台应用程序

Question

我使用 TopShelf 创建了一个 .net core 控制台应用程序。但是我在使用 docker (alpine-linux) 运行应用程序时遇到错误。

Configuration Result:
    [Success] Name MyApp
    [Success] DisplayName MyApp
    [Success] Description My Application
    [Success] ServiceName MyApp
    Topshelf v4.1.0.177, .NET Framework v4.0.30319.42000
    Topshelf.Runtime.Windows.WindowsHostEnvironment Error: 0 : Unable to get parent process (ignored), System.DllNotFoundException: Unable to load shared library 'kernel32.dll' or one of its dependencies. In order to help diagnose loading problems, consider setting the LD_DEBUG environment variable: Error loading shared library libkernel32.dll: No such file or directory
       at Topshelf.Runtime.Windows.Kernel32.CreateToolhelp32Snapshot(UInt32 dwFlags, UInt32 th32ProcessID)
       at Topshelf.Runtime.Windows.WindowsHostEnvironment.GetParent(Process child)
    Topshelf.HostFactory Error: 0 : The service terminated abnormally, System.PlatformNotSupportedException: ServiceController enables manipulating and accessing Windows services and it is not applicable for other operating systems.
       at System.ServiceProcess.ServiceController.GetServices()
       at Topshelf.Runtime.Windows.WindowsHostEnvironment.IsServiceListed(String serviceName)
       at Topshelf.Hosts.ConsoleRunHost.Run()
       at Topshelf.HostFactory.Run(Action`1 configureCallback)

如何解决这个问题？我需要将控制台应用程序作为 Windows 服务运行

Answer 1

Topshelf documentation非常具体:

To work with Topshelf you will need to be running on a Windows operating system. The developers of Topshelf regulary test on Windows 7 and Windows Server 2008RC2. Though it should still work on Windows Server 2003, as long as .Net 3.5 sp1 is installed.

好消息是writing Linux daemons比 Windows 服务更容易 - 它们基本上只是一个控制台应用程序，您可以在其中控制主循环。

如果我正确理解了您的问题陈述，您希望能够在 Windows 和 Docker 中运行一项服务。在这种情况下，最简单的方法似乎是在启动时检查您的操作系统环境，例如 System.Runtime.InteropServices.RuntimeInformation.IsOSPlatform()要么将您的主要工作推迟到 Topshelf，要么以 Linux 方式运行。对于下面的示例，我安装了 Microsoft.Extensions.Hosting 包并选择实现 IHostedService (Topshelf 可以方便地重复使用)

public class YourHostedService : IHostedService, IDisposable
{
    private int executionCount = 0;
    private Timer _timer;

    public YourHostedService()
    {
    }

    public Task StartAsync(CancellationToken stoppingToken)
    {
        _timer = new Timer(DoWork, null, TimeSpan.Zero,
            TimeSpan.FromSeconds(5));

        return Task.CompletedTask;
    }

    private void DoWork(object state)
    {
        executionCount++;// this gets called every 5 seconds
    }

    public Task StopAsync(CancellationToken stoppingToken)
    {
        _timer?.Change(Timeout.Infinite, 0);
        return Task.CompletedTask;
    }

    public void Dispose() => _timer?.Dispose();
}

public class Program
{
    public static async Task Main(string[] args)
    {
        if (RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
        {
            var rc = HostFactory.Run(x =>
            {
                var token = CancellationToken.None;
                x.Service<YourHostedService>(s =>
                {
                    s.ConstructUsing(name => new YourHostedService());
                    s.WhenStarted(tc => tc.StartAsync(token));
                    s.WhenStopped(tc => tc.StopAsync(token));
                });
                x.RunAsLocalSystem();

                x.SetDescription("TopShelf Host");
                x.SetDisplayName("YourHostedService");
                x.SetServiceName("YourHostedService");
            });
        }
        else
        {
            await Host.CreateDefaultBuilder(args)
                .ConfigureServices(builder =>
                {
                    builder.AddHostedService<YourHostedService>();
                })
                .RunConsoleAsync();
        }
    }
}

可以汲取更多灵感from here .

UPD 所以看来您的特殊情况也可以通过将任意(好吧，在本例中是您的)程序作为 Windows 服务运行来解决。在这种情况下，您有一些不涉及编程但涉及配置编写的选项:

1. Microsoft's own tool SrvAny这是 NT 资源工具包的一部分:您基本上将其安装为虚拟服务并编辑注册表设置以指向您的 .exe
2. 一个3rd party tool SrvStart :这个也比较容易上手，配置与上面类似