ASP.NET server + HttpClient over custom Stream(s)

[lostmsu]

How do I configure my ASP.NET app to use a custom transport mechanism?

E.g. on the server side I have an event that fires whenever some client is connected and passes a Stream object. I want my ASP.NET app to respond to HTTP requests sent over that Stream instead of the usual TCP.

And on the client side I need to configure HttpClient so that it called my transport mechanism's Stream Connect(string host) method.

The transport mechanism abstractions involved may vary, but ideally I want minimal modifications to the ASP.NET app and keep HttpClient as the access abstraction. Ideally the client should be able to send multiple interleaved requests over the same connection.

[lostmsu]

OK, I figured I can implement IConnectionListenerFactory similar to https://github.com/dotnet/aspnetcore/blob/v8.0.1/src/Servers/Kestrel/Transport.NamedPipes/src/Internal/NamedPipeTransportFactory.cs

What remains unclear is the HttpClient side.

[davidfowl]

It's your lucky day, I happen to have implemented this:

Server:
https://github.com/davidfowl/YarpTunnelDemo/tree/main/Backend/Transport

Client:
https://github.com/davidfowl/YarpTunnelDemo/blob/main/Frontend/Tunnel/TunnelClientFactory.cs

There's some YARP goop in there but for HttpClient you can do:

var client = new HttpClient(new SocketsHttpHandler { ConnectCallback = .. } )

That connect callback allows you to return a custom stream. See https://learn.microsoft.com/en-us/dotnet/api/system.net.http.socketshttphandler.connectcallback?view=net-7.0