Can I tell if I'm running in systemd?

Question

I have a Python service in systemd. I'd like to have it use the Python syslog module for logging if it's running in systemd vs. otherwise. Is there a reliable way to determine if I'm running in systemd or is there a better way of going about it?

why not have your python program have a flag like --syslog, then pass that flag with the systemd service? — user530873, Apr 05 '16 at 21:31
I can do that. I was just wondering if there's still a way to determine whether I'm in SystemD. — Naftuli Kay, Apr 05 '16 at 21:35
https://serverfault.com/questions/926349/systemd-tell-if-script-was-run-by-systemd-or-by-user — gavv, Nov 17 '19 at 16:51

score 2 · Answer 1 · answered Apr 05 '16 at 21:43

2

systemd will always have a PID of 1, so you can check if the parent PID is 1:

import psutil, os
if psutil.Process(os.getpid()).ppid() == 1:
    # We are using systemd

However, it's probally better to offer a command line flag --syslog and pass that with the systemd service, this way the user can select to use syslog even without the systemd service.

answered Apr 05 '16 at 21:43

user530873

257
1
8

Won't init also be pid 1? – Jeff Schaller Apr 05 '16 at 21:46
@JeffSchaller hence the reason I recommend the command line flag – user530873 Apr 05 '16 at 21:47
Not working for me. – gavv Nov 17 '19 at 16:51

Can I tell if I'm running in systemd?

1 Answers1