Hi, Mathieu Othacehe <othac...@gnu.org> skribis:
>> This sounds a lot like this: >> >> https://issues.guix.gnu.org/32182#1 > > I was just kicked out of my own server due to this PAM/SSH issue. It > happens quite frequently here. Time for a fix :). Note that ‘guix deploy’ now opens a single SSH session, starting from 7f20e59a13a6acc3331e04185b8f1ed2538dcd0a, which might help mitigate the problem. > Regarding the two potential solutions that you proposed in 2018, are > they still actual? If yes, I could maybe try to implement the second > suggestion: introducing service chain-loading. Service chain-loading was implemented in the Shepherd a few years ago. However, it doesn’t really help; consider these two scenario: • You do ‘guix system reconfigure && herd restart term-tty1’. In that case, all is good: ‘term-tty1’, will run the new ‘mingetty’ process (post-glibc upgrade, thanks to service chain-loading) and ‘login’ will happily load the .so files listed in /etc/pam.d/login (also post-glibc upgrade). • You run ‘guix system reconfigure’ but do not restart ‘term-tty1’, ‘sshd’, and all the other services that depend on PAM: these pre-glibc upgrade programs will try dlopening the post-glibc upgrade PAM plugins, which will break. The crux of the problem rather is the global /etc/pam.d: it’s valid for pre-glibc upgrade programs, or for post-glibc upgrade programs, but not both. FHS distros have a similar problem though; how do they handle it? Do they force services to be restarted when glibc is upgraded, or something along these lines? In our case, suppose libpam honors $PAM_DIRECTORY; we could tweak each PAM-using Shepherd service (login, sshd, etc.) so that it sets PAM_DIRECTORY… but how would we get the PAM_DIRECTORY value for the OS being configured? Tricky! We could maybe sidestep the issue altogether with socket-activated services: they’d be started on-demand, so the second scenario above would be unlikely. But getting there is quite a bit of work… Ludo’.
