将项目部署到ubuntu上面以后，运行，竟然报错：

ubuntu@VM-4-11-ubuntu:~/publish$ uname -a
Linux VM-4-11-ubuntu 5.4.0-121-generic #137-Ubuntu SMP Wed Jun 15 13:33:07 UTC 2022 x86_64 x86_64 x86_64 GNU/Linux
ubuntu@VM-4-11-ubuntu:~/publish$ 

ubuntu@VM-4-11-ubuntu:~/publish$ ./qhxyhs

==================西宁威势电子提供此程序==================

8/27/2022 7:07:25 PM:   数据库初始化专题数量1条
8/27/2022 7:07:26 PM:   数据库初始化频道数量5条
8/27/2022 7:07:26 PM:   数据库初始化系统权限模块数量47条
8/27/2022 7:07:26 PM:   数据库初始化系统用户数量3条
8/27/2022 7:07:26 PM:   数据库初始化用户角色数量3条
8/27/2022 7:07:26 PM:   数据库初始化API商家演示接口数量5条
8/27/2022 7:07:26 PM:   数据库初始化频道单页面数量3条
8/27/2022 7:07:26 PM:   数据库初始化频道新闻页面5条
8/27/2022 7:07:26 PM:   数据库初始化完成.

Unhandled exception. System.Net.Sockets.SocketException (13): Permission denied
   at System.Net.Sockets.Socket.UpdateStatusAfterSocketErrorAndThrowException(SocketError , String )
   at System.Net.Sockets.Socket.DoBind(EndPoint , SocketAddress )
   at System.Net.Sockets.Socket.Bind(EndPoint )
   at Microsoft.AspNetCore.Server.Kestrel.Transport.Sockets.SocketTransportOptions.CreateDefaultBoundListenSocket(EndPoint endpoint)
   at Microsoft.AspNetCore.Server.Kestrel.Transport.Sockets.SocketConnectionListener.Bind()
   at Microsoft.AspNetCore.Server.Kestrel.Transport.Sockets.SocketTransportFactory.BindAsync(EndPoint endpoint, CancellationToken cancellationToken)
   at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Infrastructure.TransportManager.BindAsync(EndPoint endPoint, ConnectionDelegate connectionDelegate, EndpointConfig endpointConfig, CancellationToken cancellationToken)
   at Microsoft.AspNetCore.Server.Kestrel.Core.KestrelServerImpl.<>c__DisplayClass30_0`1.<<StartAsync>g__OnBind|0>d.MoveNext()
--- End of stack trace from previous location ---
   at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.AddressBinder.BindEndpointAsync(ListenOptions endpoint, AddressBindContext context, CancellationToken cancellationToken)
   at Microsoft.AspNetCore.Server.Kestrel.Core.ListenOptions.BindAsync(AddressBindContext context, CancellationToken cancellationToken)
   at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.AddressBinder.AddressesStrategy.BindAsync(AddressBindContext context, CancellationToken cancellationToken)
   at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.AddressBinder.BindAsync(IEnumerable`1 listenOptions, AddressBindContext context, CancellationToken cancellationToken)
   at Microsoft.AspNetCore.Server.Kestrel.Core.KestrelServerImpl.BindAsync(CancellationToken cancellationToken)
   at Microsoft.AspNetCore.Server.Kestrel.Core.KestrelServerImpl.StartAsync[TContext](IHttpApplication`1 application, CancellationToken cancellationToken)
   at Microsoft.AspNetCore.Hosting.GenericWebHostService.StartAsync(CancellationToken cancellationToken)
   at Microsoft.Extensions.Hosting.Internal.Host.StartAsync(CancellationToken )
   at Microsoft.Extensions.Hosting.HostingAbstractionsHostExtensions.RunAsync(IHost , CancellationToken )
   at Microsoft.Extensions.Hosting.HostingAbstractionsHostExtensions.RunAsync(IHost , CancellationToken )
   at Microsoft.Extensions.Hosting.HostingAbstractionsHostExtensions.Run(IHost )
   at WinsMVC.Program.Main(String[] args) in X:\WEB\Program.cs:line 41
Aborted (core dumped)

看提示，应该是权限拒绝引起的。在lunchSetting.json中有如下定义：

"applicationUrl": "https://www.xxx.com;http://www.xxx.com;",  

奇怪的是，将https协议剔除以后再次部署运行，程序又可以正常启动，但是端口被绑定到5000上面去了。于是在startup.cs中强行绑定端口试试：

webBuilder.UseKestrel() .UseUrls($"http://"+System.Net.IPAddress.Any+":80") .UseStartup<Startup>();

但是还是报同样的错。后来经过一凡查阅资料与测试，发现绑定低端端口的时候就会报错，将端口改为3389后再运行，发现代码又可以正常运行了，高端口（ >1024）没有问题。看来确实是权限原因引起的,如果是root权限，应该是没问题的，条件不成熟，没有测试。

这些是查阅到的资料

PROBLEM: Rancher reported "unable to start kestrel" and Access Denied
REASON: This happen because port 80 is low port and need adminstrator permissions
SOLUTION: Use port 8080