托管在

时间:2016-11-09 11:39:46

标签: c# linux docker servicestack .net-core

免责声明 - 这与docker container exits immediately even with Console.ReadLine() in a .net core console application几乎是同一个问题 - 但我不认为这个问题的公认答案是令人满意的。

我想要实现的目标
我正在构建一个控制台应用程序(它是一个使用ServiceStack的HTTP服务),它是用.NET核心构建的(dnxcore50 - 这是一个控制台应用程序,而不是ASP.NET应用程序)。我在Linux机器上的docker容器中运行此应用程序。我已经完成了,HTTP服务正常工作。

我的问题
说过“我的服务有效” - 确实如此,在docker容器中托管服务存在问题。我在启动HTTP侦听器后使用Console.ReadLine(),但此代码不会在docker容器中阻塞,并且容器将在启动后立即退出。我可以在“交互”模式下启动docker容器,服务将在那里监听,直到我终止交互式会话,然后容器将退出。

回购代码
下面的代码是一个完整的代码清单,用于创建我的测试.NET核心Servicestack控制台应用程序。

public class Program
{
    public static void Main(string[] args)
    {
        new AppHost().Init().Start("http://*:8088/");
        Console.WriteLine("listening on port 8088");
        Console.ReadLine();

    }
}

public class AppHost : AppSelfHostBase
{
    // Initializes your AppHost Instance, with the Service Name and assembly containing the Services
    public AppHost() : base("My Test Service", typeof(MyTestService).GetAssembly()) { }

    // Configure your AppHost with the necessary configuration and dependencies your App needs
    public override void Configure(Container container)
    {

    }
}

public class MyTestService: Service
{
    public TestResponse Any(TestRequest request)
    {
        string message = string.Format("Hello {0}", request.Name);
        Console.WriteLine(message);
        return new TestResponse {Message = message};
    }

}

[Api("Test method")]
[Route("/test/{Name}", "GET", Summary = "Get Message", Notes = "Gets a message incorporating the passed in name")]
public class TestRequest : IReturn<TestResponse>
{
    [ApiMember(Name = "Name", Description = "Your Name", ParameterType = "path", DataType = "string")]
    public string Name { get; set; }
}

public class TestResponse 
{
    [ApiMember(Name = "Message", Description = "A Message", ParameterType = "path", DataType = "string")]
    public string Message { get; set; }
}

解决此问题的旧方法
所以以前使用Mono托管(Mono有严重的性能问题 - 因此切换到.NET内核) - 修复此行为的方法是使用Mono.Posix监听这样的kill信号:

using Mono.Unix;
using Mono.Unix.Native;

...

static void Main(string[] args)
    {
        //Start your service here...

        // check if we're running on mono
        if (Type.GetType("Mono.Runtime") != null)
        {
            // on mono, processes will usually run as daemons - this allows you to listen
            // for termination signals (ctrl+c, shutdown, etc) and finalize correctly
            UnixSignal.WaitAny(new[] {
                new UnixSignal(Signum.SIGINT),
                new UnixSignal(Signum.SIGTERM),
                new UnixSignal(Signum.SIGQUIT),
                new UnixSignal(Signum.SIGHUP)
            });
        }
        else
        {
            Console.ReadLine();
        }
    }

现在 - 我明白这对.NET Core不起作用(显然是因为Mono.Posix适用于Mono!)

相关文章(本文顶部)中概述的解决方案对我没有用处 - 在生产环境中,我不能指望通过确保它具有可用的交互式会话来保持docker容器的活着。 Console.ReadLine正常工作,因为那里有STD-IN流...

在托管.NET Core应用程序时,还有另一种方法可以让我的docker容器保持活动状态(在调用-d时使用docker run(分离)选项吗?

代码重构是Mythz建议的一部分

 public static void Main(string[] args)
    {
        Run(new AppHost().Init(), "http://*:8088/");
    }

    public static void Run(ServiceStackHost host, params string[] uris)
    {
        AppSelfHostBase appSelfHostBase = (AppSelfHostBase)host;

        using (IWebHost webHost = appSelfHostBase.ConfigureHost(new WebHostBuilder(), uris).Build())
        {
            ManualResetEventSlim done = new ManualResetEventSlim(false);
            using (CancellationTokenSource cts = new CancellationTokenSource())
            {
                Action shutdown = () =>
                {
                    if (!cts.IsCancellationRequested)
                    {
                        Console.WriteLine("Application is shutting down...");
                        cts.Cancel();
                    }

                    done.Wait();
                };

                Console.CancelKeyPress += (sender, eventArgs) =>
                {
                    shutdown();
                    // Don't terminate the process immediately, wait for the Main thread to exit gracefully.
                    eventArgs.Cancel = true;
                };

                Console.WriteLine("Application started. Press Ctrl+C to shut down.");
                webHost.Run(cts.Token);
                done.Set();
            }
        }
    }

最终解决方案!

对于后代 - 我所使用的解决方案是可在此处找到的代码(感谢神话澄清):https://github.com/NetCoreApps/Hello/blob/master/src/SelfHost/Program.cs

相关代码的回购:

public static void Main(string[] args)
    {
        var host = new WebHostBuilder()
            .UseKestrel()
            .UseContentRoot(Directory.GetCurrentDirectory())
            .UseStartup<Startup>()
            .UseUrls("http://*:8088/")
            .Build();

        host.Run();
    }
}

public class Startup
{
    // This method gets called by the runtime. Use this method to add services to the container.
    public void ConfigureServices(IServiceCollection services)
    {
    }

    // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
    public void Configure(IApplicationBuilder app, IHostingEnvironment env)
    {
        // app.UseStaticFiles();

        app.UseServiceStack(new AppHost());

        app.Run(context =>
        {
            context.Response.Redirect("/metadata");
            return Task.FromResult(0);
        });
    }

在NuGet中,我安装了Microsoft.NETCore.App,ServiceStack.Core和ServiceStack.Kestrel。

1 个答案:

答案 0 :(得分:10)

如果您要在Docker中托管.NET Core应用程序,我建议您按照正常的.NET Core Hosting API调用IWebHost.Run()来阻止主线程并保留控制台应用程序活着。

AppHostSelfBase仅为wrapper around .NET Core's hosting API,但会调用非阻塞IWebHost.Start()。要获得IWebHost.Run()的行为,您应该能够重用ManualResetEventSlimConsole.CancelKeyPress WebHost.Run()'s implementation uses的相同方法,但就个人而言,它更容易使用。 NET Core的托管API并致电Run()并致电register your ServiceStack AppHost as a .NET Core module