For p2phttp support in forgejo-aneksajo I decided to just spawn a git annex p2phttp --wideopen server, do authentication on the Forgejo side, and then proxy requests to p2phttp. Since p2phttp only supports serving one repository at the moment this means that I have to allocate one free port per repository. Actually finding a free port adds complexity and a race condition, as there also seems to be no way to set --port 0 for p2phttp and then figure out which port it bound to.

This would be simplified if p2phttp could listen on unix domain sockets instead.