一、背景
NetCore作为微服务可以注册到服务中心，服务中心可以远程启动、重启、关闭该微服务
二、实现
1、创建一个NetCore 2.0 WebApi项目
2、创建一个进程去管理NetCore程序进程
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public class ApplicationManager { private static ApplicationManager _appManager; private IWebHost _web; private CancellationTokenSource _tokenSource; private bool _running; private bool _restart; public bool Restarting => _restart; public ApplicationManager() { _running = false; _restart = false; } public static ApplicationManager Load() { if (_appManager == null) _appManager = new ApplicationManager(); return _appManager; } public void Start() { if (_running) return; if (_tokenSource != null && _tokenSource.IsCancellationRequested) return; _tokenSource = new CancellationTokenSource(); _tokenSource.Token.ThrowIfCancellationRequested(); _running = true; _web = new WebHostBuilder() .UseKestrel() .UseContentRoot(Directory.GetCurrentDirectory()) .UseIISIntegration() .UseStartup<Startup>() .Build(); _web.Run(_tokenSource.Token); } public void Stop() { if (!_running) return; _tokenSource.Cancel(); _running = false; } public void Restart() { Stop(); _restart = true; _tokenSource = null; } } |
3、把ApplicationManager加入到Main中
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public static void Main(string[] args) { try { var appManager = ApplicationManager.Load(); do { appManager.Start(); } while (appManager.Restarting); } catch (Exception ex) { } } |
4、在程序的ValuesController中实现重启、关闭的Api
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using System;using System.Collections.Generic;using System.Linq;using System.Threading.Tasks;using Microsoft.AspNetCore.Mvc;namespace NetCoreWebApiDemo.Controllers{ [Route("api/[controller]")] public class ValuesController : Controller { private ApplicationManager appManager = ApplicationManager.Load(); // GET api/values [HttpGet] public IEnumerable<string> Get() { return new string[] { "value1", "value2" }; } // GET api/values/5 [HttpGet("{cmd}")] public string Get(string cmd) { switch (cmd) { case "restart": appManager.Restart(); break; case "stop": appManager.Stop(); break; case "start": appManager.Start(); break; } return cmd; } // POST api/values [HttpPost] public void Post([FromBody]string value) { } // PUT api/values/5 [HttpPut("{id}")] public void Put(int id, [FromBody]string value) { } // DELETE api/values/5 [HttpDelete("{id}")] public void Delete(int id) { } }} |
6、给程序启动和停止加入日志标签
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using System;using System.Collections.Generic;using System.Linq;using System.Threading.Tasks;using Microsoft.AspNetCore.Builder;using Microsoft.AspNetCore.Hosting;using Microsoft.Extensions.Configuration;using Microsoft.Extensions.DependencyInjection;using Microsoft.Extensions.Logging;using Microsoft.Extensions.Options;namespace NetCoreWebApiDemo{ public class Startup { public Startup(IConfiguration configuration) { Configuration = configuration; } public IConfiguration Configuration { get; } // This method gets called by the runtime. Use this method to add services to the container. public void ConfigureServices(IServiceCollection services) { services.AddMvc(); } // This method gets called by the runtime. Use this method to configure the HTTP request pipeline. public void Configure(IApplicationBuilder app, IHostingEnvironment env, IApplicationLifetime lifetime) { if (env.IsDevelopment()) { app.UseDeveloperExceptionPage(); } app.UseMvc(); lifetime.ApplicationStarted.Register(OnStart);//1:应用启动时加载配置,2:应用启动后注册服务中心 lifetime.ApplicationStopped.Register(UnRegService);//应用停止后从服务中心注销 } private void OnStart() { LoadAppConfig(); RegService(); } private void LoadAppConfig() { //加载应用配置 Console.WriteLine("ApplicationStarted:LoadAppConfig"); } private void RegService() { //先判断是否已经注册过了 //this code is called when the application stops Console.WriteLine("ApplicationStarted:RegService"); } private void UnRegService() { //this code is called when the application stops Console.WriteLine("ApplicationStopped:UnRegService"); } }} |
5、在程序根目录运行dotnet run
访问：http://localhost:51062/api/values,显示：["Value1","Value2"]
访问：http://localhost:51062/api/values/restart:显示restart，再访问http://localhost:51062/api/values正常返回["Value1","Value2"]
访问：http://localhost:51062/api/values/stop，显示：stop,再访问http://localhost:51062/api/values就是404了
stop后由于netcore进程已经被关闭，没有了http监听,通过url方式是无法重新启动了，这里可以借助类似supervisor的工具来停止进程，启动进程。
三、源码地址
https://github.com/andrewfry/AspNetCore-App-Restart
四、其它实现
1、除了上面，还可以通过中间件的形式，实现远程关闭
新增一个中间件的类：
public class RemoteStopMiddleware
{
private RequestDelegate _next;
private const string RequestHeader = "Stop-Application";
private const string ResponseHeader = "Application-Stopped";
public RemoteStopMiddleware(RequestDelegate next)
{
_next = next;
}
public async Task Invoke(HttpContext context, IApplicationLifetime lifetime)
{
if (context.Request.Method == "HEAD" && context.Request.Headers[RequestHeader].FirstOrDefault() == "Yes")
{
context.Response.Headers.Add(ResponseHeader, "Yes");
lifetime.StopApplication();
}
else if (context.Request.Method == "HEAD" && context.Request.Headers[RequestHeader].FirstOrDefault() == "No")
{
context.Response.Headers.Add(ResponseHeader, "No");
// See you on the next request.
//Program.Shutdown();
}
else
{
await _next(context);
}
}
}
2、注册中间件
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public void Configure(IApplicationBuilder app, IHostingEnvironment env, IApplicationLifetime lifetime) { if (env.IsDevelopment()) { app.UseDeveloperExceptionPage(); } app.UseMvc(); app.UseMiddleware<RemoteStopMiddleware>(); lifetime.ApplicationStarted.Register(OnStart);//1:应用启动时加载配置,2:应用启动后注册服务中心 lifetime.ApplicationStopped.Register(UnRegService);//应用停止后从服务中心注销 } |
3、运行程序，用postman发起一个head请求，请求头中加
{
Stop-Application：Yes
}
详细说明可参考：https://www.cnblogs.com/artech/p/application-life-time.html
