ASP.NET Core with Angular throws Exception on startup after publish

[kratofl]

Is there an existing issue for this?

• I have searched the existing issues

Describe the bug

When I publish my ASP.NET Core application with angular I get an exception:

Expected Behavior

I should not throw an exception on startup.

Steps To Reproduce

1. Create and project with the template: "Angular and ASP.NET Core"
   
2. Start it once to test
3. Publish to local folder
   
4. Start the .exe file.

Exceptions (if any)

warn: Microsoft.AspNetCore.StaticFiles.StaticFileMiddleware[16]
The WebRootPath was not found: C:\source\repos\AngularApp1\AngularApp1.Server\bin\Release\net8.0\wwwroot. Static files may be unavailable.
warn: Microsoft.AspNetCore.StaticFiles.StaticFileMiddleware[16]
The WebRootPath was not found: C:\source\repos\AngularApp1\AngularApp1.Server\bin\Release\net8.0\wwwroot. Static files may be unavailable.
fail: Microsoft.Extensions.Hosting.Internal.Host[11]
Hosting failed to start
System.IO.IOException: Failed to bind to address http://[::]:8080: address already in use.
---> Microsoft.AspNetCore.Connections.AddressInUseException: Only one usage of each socket address (protocol/network address/port) is normally permitted.
---> System.Net.Sockets.SocketException (10048): Only one usage of each socket address (protocol/network address/port) is normally permitted.
at System.Net.Sockets.Socket.UpdateStatusAfterSocketErrorAndThrowException(SocketError error, Boolean disconnectOnFailure, String callerName)
at System.Net.Sockets.Socket.DoBind(EndPoint endPointSnapshot, SocketAddress socketAddress)
at System.Net.Sockets.Socket.Bind(EndPoint localEP)
at Microsoft.AspNetCore.Server.Kestrel.Transport.Sockets.SocketTransportOptions.CreateDefaultBoundListenSocket(EndPoint endpoint)
at Microsoft.AspNetCore.Server.Kestrel.Transport.Sockets.SocketConnectionListener.Bind()
--- End of inner exception stack trace ---
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__DisplayClass28_01.<<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) --- End of inner exception stack trace --- 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.AnyIPListenOptions.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(ListenOptions[] listenOptions, AddressBindContext context, Func2 useHttps, CancellationToken cancellationToken)
at Microsoft.AspNetCore.Server.Kestrel.Core.KestrelServerImpl.BindAsync(CancellationToken cancellationToken)
at Microsoft.AspNetCore.Server.Kestrel.Core.KestrelServerImpl.StartAsync[TContext](IHttpApplication1 application, CancellationToken cancellationToken) at Microsoft.AspNetCore.Hosting.GenericWebHostService.StartAsync(CancellationToken cancellationToken) at Microsoft.Extensions.Hosting.Internal.Host.<StartAsync>b__15_1(IHostedService service, CancellationToken token) at Microsoft.Extensions.Hosting.Internal.Host.ForeachService[T](IEnumerable1 services, CancellationToken token, Boolean concurrent, Boolean abortOnFirstException, List1 exceptions, Func3 operation)
Unhandled exception. System.IO.IOException: Failed to bind to address http://[::]:8080: address already in use.
---> Microsoft.AspNetCore.Connections.AddressInUseException: Only one usage of each socket address (protocol/network address/port) is normally permitted.
---> System.Net.Sockets.SocketException (10048): Only one usage of each socket address (protocol/network address/port) is normally permitted.
at System.Net.Sockets.Socket.UpdateStatusAfterSocketErrorAndThrowException(SocketError error, Boolean disconnectOnFailure, String callerName)
at System.Net.Sockets.Socket.DoBind(EndPoint endPointSnapshot, SocketAddress socketAddress)
at System.Net.Sockets.Socket.Bind(EndPoint localEP)
at Microsoft.AspNetCore.Server.Kestrel.Transport.Sockets.SocketTransportOptions.CreateDefaultBoundListenSocket(EndPoint endpoint)
at Microsoft.AspNetCore.Server.Kestrel.Transport.Sockets.SocketConnectionListener.Bind()
--- End of inner exception stack trace ---
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__DisplayClass28_01.<<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) --- End of inner exception stack trace --- 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.AnyIPListenOptions.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(ListenOptions[] listenOptions, AddressBindContext context, Func2 useHttps, CancellationToken cancellationToken)
at Microsoft.AspNetCore.Server.Kestrel.Core.KestrelServerImpl.BindAsync(CancellationToken cancellationToken)
at Microsoft.AspNetCore.Server.Kestrel.Core.KestrelServerImpl.StartAsync[TContext](IHttpApplication1 application, CancellationToken cancellationToken) at Microsoft.AspNetCore.Hosting.GenericWebHostService.StartAsync(CancellationToken cancellationToken) at Microsoft.Extensions.Hosting.Internal.Host.<StartAsync>b__15_1(IHostedService service, CancellationToken token) at Microsoft.Extensions.Hosting.Internal.Host.ForeachService[T](IEnumerable1 services, CancellationToken token, Boolean concurrent, Boolean abortOnFirstException, List1 exceptions, Func3 operation)
at Microsoft.Extensions.Hosting.Internal.Host.StartAsync(CancellationToken cancellationToken)
at Microsoft.Extensions.Hosting.HostingAbstractionsHostExtensions.RunAsync(IHost host, CancellationToken token)
at Microsoft.Extensions.Hosting.HostingAbstractionsHostExtensions.RunAsync(IHost host, CancellationToken token)
at Microsoft.Extensions.Hosting.HostingAbstractionsHostExtensions.Run(IHost host)
at Program.

$(String[] args) in C:\source\repos\AngularApp1\AngularApp1.Server\Program.cs:line 30

.NET Version

8.0.204

Anything else?

• Visual Studio 2022 Windows: 17.9.6
• Node: v20.12.2
• Angular: 17.3.0
• I've triple checked it, nothing is running on port 8080 already

[amcasey]

That error appears to say that the port is already in use. You shut down the instance you ran to test the project in step (2) before running another copy in step (4)?

Edit: just noticed the note at the bottom of your report. How are you confirming that 8080 is available?

[amcasey]

@danroth27 Is that template owned by aspnetcore or JavaScript/TypeScript?

[amcasey]

I did my best to follow those repro steps and didn't see that behavior. It wasn't specified, but I assumed it was the AngularApp1.Server project that I should publish to a local folder. I'm a little curious how yours ended up on port 8080 - launchSettings.json appears to specify a random port and running the exe directly appears to default to 5000.

[danroth27]

@danroth27 Is that template owned by aspnetcore or JavaScript/TypeScript?

This template is owned by @joj's team, but we work pretty closely with them on it.

[kratofl]

I did my best to follow those repro steps and didn't see that behavior. It wasn't specified, but I assumed it was the AngularApp1.Server project that I should publish to a local folder. I'm a little curious how yours ended up on port 8080 - launchSettings.json appears to specify a random port and running the exe directly appears to default to 5000.

Ok. I've sort of "fixed" it.
I forgot that I set the environment variable (ASPNETCORE_URLS), but it was a while ago.

I've removed that entry and now it works. But I'm still curious why it didn't work.

[kratofl]

But theres another issue.
The compiled angular code is put into "wwwroot/browser".
And I cannot access the page.
But when I move the compiled angular files out of the browser folder directly into wwwroot, then it works.
Any idea why?

[amcasey]

But I'm still curious why it didn't work [with ASPNETCORE_URLS].

Presumably, another process was consuming the same environment variable. You could check using something like netstat.

But theres another issue.

Can you please provide new repro steps? Are you using the built app or the published one? How did you try to access the page? What behavior did you see when you failed to access it?

[kratofl]

Sorry for the late response

Can you please provide new repro steps? Are you using the built app or the published one? How did you try to access the page? What behavior did you see when you failed to access it?

I use the published one, the build one works fine with the debugger.
I've tried to access it with "localhost:5000".
It just says that the page isn't working.
But after moving the content from the sub directory to wwwroot directly it works fine.

[amcasey]

I've tried to access it with "localhost:5000".

I'm assuming you mean in a browser, as opposed to curl or HttpClient?

It just says that the page isn't working.

Is it the client or the server saying that? What does the server log show?