====== Shutting Up PAM in Syslogs ======
In a Debian-like system, the easiest way is to use ''pam-auth-update'' to manage PAM.
To silence specific services, make a file like the following:

''/usr/share/pam-configs/shutup''
  # Don't log "session opened" and "session closed" messages for...
  # Cron, Samba
  # See: https://wiki.ubuntu.com/PAMConfigFrameworkSpec
  #      https://manpages.debian.org/stretch/libpam-modules/pam_succeed_if.8.en.html
  Name: disable annoying services session logging
  Default: yes
  Priority: 300
  Session-Type: Additional
  Session:
      [default=ignore success=1] pam_succeed_if.so quiet service in samba:cron

This silences samba and cron. ''quiet'' means that this rule always succeeds or fails silently. ''success=1'' skips the next rule (i.e. ''pam_unix''), silencing a session open/close. You can also specify users only by replacing ''service in samba:cron'' with something like ''ruser in michael:otheruser''.

After doing this, run ''pam-auth-update'' as root, selecting the configuration you just made. You can programmatically update configs by passing ''--package'', preventing options from needing to be chosen by the user.