The sshd service can not work correctly in the container

[kuangllbnu]

BG: I just want to use ssh in containers. I could successfully start the sshd in docker containers and login from other terminals. But failed when I use Slurm with pyxis to start the container.

Here is an screenshot.

If I start the sshd in the container with port 2222, when I try to login with ssh -p 2222, "Connection closed" was reported (Attached screen). If I kill the sshd, then try to login with ssh -p 2222, certainly "Connection refused" was shown.

[flx42]

My understanding is that sshd by default verifies it can actually drop privileges: https://github.com/openssh/openssh-portable/blob/141535b904b6fba01724444f38193a8599201f82/uidswap.c

So I don't think enroot can work with this use case given what it does to intercept setuid/setgid calls with seccomp, so you need to use --no-container-remap-root to run sshd as non-root.

[3XX0]

Yes, see also https://github.com/NVIDIA/enroot/issues/92#issuecomment-922088508

[kuangllbnu]

My understanding is that sshd by default verifies it can actually drop privileges: https://github.com/openssh/openssh-portable/blob/141535b904b6fba01724444f38193a8599201f82/uidswap.c

So I don't think enroot can work with this use case given what it does to intercept setuid/setgid calls with seccomp, so you need to use --no-container-remap-root to run sshd as non-root.

It could not work either, when I delete the option --no-container-remap-root

[flx42]

You need to add --no-container-remap-root