[slurm-users] Kernel keyrings on Slurm node inside Slurm job

[Matthias Leopold]

Hi,

I want to access the kernel "user" keyrings inside a Slurm job on a 
Ubuntu 20.04 node. I'm not an expert on keyrings (yet), I just 
discovered that inside a Slurm job a keyring for "user: invocation_id" 
is used, which seems to be shared across all users of the executing 
Slurm node (other users can access/destroy my keys).

The structure in a session run from Slurm looks like this (when using 
cifscreds):

Session Keyring

  989278347 --alswrv      0     0  keyring: _ses

  446567140 ----s-rv      0     0   \_ user: invocation_id

  638050420 ----sw-v  35816 10513   \_ logon: cifs:d:itsc-test2


The structure in a SSH session looks like this (when using cifscreds):

Session Keyring

  932177825 --alswrv   1000  1000  keyring: _ses

  826996940 --alswrv   1000 65534   \_ keyring: _uid.1000

1006610690 ----sw-v   1000  1000   \_ logon: cifs:d:itsc-test2


I researched about this invocation_id and found a section on 
"KeyringMode=" in systemd.exec man page, but that didn't really help me.

Can you explain to me how it would be possible to get "private" keyrings 
inside a Slurm job on the executing node?

thx
Matthias