Failed to bind to address http://127.0.0.1:5000: address already in use.

[OpenSpacesAndPlaces]

Attempting to add a YARP site on a server that already has IIS for sites.
From my understanding I need to auto-bind to an open port, but ""{**catch-all}"" seems to be the wrong setting.

What is the correct configuration to be able to run YARP side by side with IIS?

Any help appreciated - thanks!

 "ReverseProxy": {
   "Routes": {
     "route1" : {
       "ClusterId": "cluster1",
       "Match": {
         "Path": "{**catch-all}"
       },
     }
   },
   "Clusters": {
     "cluster1": {
       "Destinations": {
         "destination1": {
           "Address": "https://example.com/"
         }
       }
     }
   }
 }
}

Application: MySite.exe
CoreCLR Version: 6.0.21.52210
.NET Version: 6.0.0
Description: The process was terminated due to an unhandled exception.
Exception Info: System.IO.IOException: Failed to bind to address http://127.0.0.1:5000: 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, 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__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)
   --- 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.LocalhostListenOptions.BindAsync(AddressBindContext context, CancellationToken cancellationToken)
   at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.AddressBinder.DefaultAddressStrategy.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 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 Microsoft.AspNetCore.Builder.WebApplication.Run(String url)
   at Program.<Main>$(String[] args) in C:\...\workspace\MySite_deploy-dev\Web\Program.cs:line 927
   at Program.<Main>(String[] args)

[Tratcher]

The ReverseProxy config section is unrelated to the incoming server bindings and that port conflict error. You need to configure the kestrel server bindings like this:
https://docs.microsoft.com/en-us/aspnet/core/fundamentals/servers/kestrel/endpoints?view=aspnetcore-6.0

[OpenSpacesAndPlaces]

"Kestrel": {
"EndPoints": {
"Https": {
"Url": "https://example.com:*"
}
}
}

[OpenSpacesAndPlaces]

Thanks

[OpenSpacesAndPlaces]

I'm running into one last problem - with IIS already on the server it won't let me bind to 80/443.
(if we use 5000 or something like that in a test, we can load the site just fine on the server)

How do you share 80/443 between Kestrel/YARP and IIS?

@Tratcher

Application: MarketCarpenter-6.exe
CoreCLR Version: 6.0.21.52210
.NET Version: 6.0.0
Description: The process was terminated due to an unhandled exception.
Exception Info: System.Net.Sockets.SocketException (10013): An attempt was made to access a socket in a way forbidden by its access permissions.
   at System.Net.Sockets.Socket.UpdateStatusAfterSocketErrorAndThrowException(SocketError error, 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()

[Tratcher]

Kestrel and IIS can't share ports, but Http.Sys and IIS can, and you can use Http.Sys with YARP too.
https://docs.microsoft.com/en-us/aspnet/core/fundamentals/servers/httpsys?view=aspnetcore-6.0

Alternatively, you set up Kestrel/YARP on 80/443 and then put IIS on some other port and proxy to it.

[OpenSpacesAndPlaces]

Thanks for the additional - do you know what the correct way to replicate these settings in httpsys would be?

"Kestrel": {
"EndPoints": {
"Https": {
"Url": "https://example.com:443",
"SslProtocols": [ "Tls12", "Tls13" ],
"Certificate": {
"Path": "example.com.pfx",
"Password": "****"
}
},
"Http": {
"Url": "http://example.com:80"
}
},
"EndpointDefaults": {
"Protocols": "Http1AndHttp2AndHttp3"
}

[Tratcher]

Http.Sys doesn't read from the config file, other than the top level Urls key:
"Urls": "https://example.com:443;http://example.com:80"

The cert setup all happens with netsh.exe and is covered in the docs.

[OpenSpacesAndPlaces]

That appears to have worked! Thanks again!