[AspireE2E] Running two or more 9.2.1 Aspire-Starter apps with Redis project simultaneously will cause an error in one project: 'Aspire.Hosting.Dashboard.Microsoft.Extensions.Hosting.Internal.Host[11] Hosting failed to start.'

[vmykagapuz]

INSTALL STEPS

1. Clean machine: Win11 x64 24h2 ENU
2. Install VS 17.14 GA
3. Install the latest Aspire 9.2.1
   dotnet new install Aspire.ProjectTemplates::9.2.1
4. Install Docker

NOTE

1. This issue is also reproduce in VS 17.13.7
2. This issue is not consistent; sometimes, when rerunning the projects, it does not reproduce the issue again.

REPRO STEPS

1. New Project > Select .NET Aspire Starter App > .NET 9.0/8.0 target framework > .NET Aspire version (9.2) > Check 'Use Redis for caching' > Create
2. Repeat step 1 to create two or more projects
3. Run the created projects at the same time
4. Check each project's log info

ACTUAL
There are errors in the log info of one project:

Aspire1.webm

Error message:

fail: Aspire.Hosting.Dashboard.Microsoft.Extensions.Hosting.Internal.Host[11]
Hosting failed to start
System.IO.IOException: Failed to bind to address https://127.0.0.1:17092: 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.LocalhostListenOptions.BindAsync(AddressBindContext context, CancellationToken cancellationToken) at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.AddressBinder.EndpointsStrategy.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)
fail: Aspire.Hosting.Dashboard[0]
2025-05-06T10:06:22.3490000Z Unhandled exception. System.IO.IOException: Failed to bind to address https://127.0.0.1:17092: address already in use.
fail: Aspire.Hosting.Dashboard[0]
2025-05-06T10:06:22.3920000Z ---> Microsoft.AspNetCore.Connections.AddressInUseException: Only one usage of each socket address (protocol/network address/port) is normally permitted.
fail: Aspire.Hosting.Dashboard[0]
2025-05-06T10:06:22.3920000Z ---> System.Net.Sockets.SocketException (10048): Only one usage of each socket address (protocol/network address/port) is normally permitted.
fail: Aspire.Hosting.Dashboard[0]
2025-05-06T10:06:22.3920000Z at System.Net.Sockets.Socket.UpdateStatusAfterSocketErrorAndThrowException(SocketError error, Boolean disconnectOnFailure, String callerName)
fail: Aspire.Hosting.Dashboard[0]
2025-05-06T10:06:22.3920000Z at System.Net.Sockets.Socket.DoBind(EndPoint endPointSnapshot, SocketAddress socketAddress)

EXPECTED
There should be no issues in all the projects when running at the same time.

[davidfowl]

Are you saying this is a regression? This is by design. The launch profile has a hardcoded port for the project. If you run multiple the ports will conflict...