Clarification on --publish and pasta's -t and -u

[io7m]

Hello!

In podman we have the --publish option to forward ports on the host to ports on the guest. In pasta, we have the -t and -u options that appear to provide the same thing. Obviously podman predates pasta; is --publish implemented internally in terms of -t and -u? How do these two things interact? The documentation doesn't have anything to say about it, and it's not clear what would/should happen if I use mutually contradictory --publish and pasta -t/-u options.

[Luap99]

is --publish implemented internally in terms of -t and -u?

Yes, and if you give conflicting options pasta fails to start and you get an error. Options are just passed through to pasta.
Overall just stick with the podman port options as this integrates with the rest of Podman: podman inspect, podman port, etc...
Only if you want to pass somthing that is not possible via the podman option you should use the pasta options.

[io7m]

Thanks, that makes sense. Mainly I'm interested in making sure that the pasta auto-forwarding options are turned off.

[sbrivio-rh]

Yeah, they are (by default), look: https://github.com/containers/common/blob/93c5bc8305b64142d4167ba00b8ffec6781fe5aa/libnetwork/pasta/pasta_linux.go#L249

[Luap99]

I think we can make the docs more clear (they are also missing some options we set) #25769
Let me know if that is better or can be improved further.