Not exactly what you are asking for but there is a Systemd feature request to add Connect= setting to service unit files. https://github.com/systemd/systemd/iss

Not exactly what you are asking for but there is a Systemd feature request to add Connect= setting to service unit files. https://github.com/systemd/systemd/issues/23067#issuecomment-1098115045 https://github.com/systemd/systemd/issues/23067#issuecomment... (That could a be cool feature) Also interesting would be to fix the security considerations of using bypass4netns: "However, it is probably possible to connect to host loopback IPs by exploiting TOCTOU of struct sockaddr * pointers." There seems to be an implementation idea for how the problem could be fixed: https://github.com/rootless-containers/bypass4netns/issues/21 https://github.com/rootless-containers/bypass4netns/issues/2...