Allows boostrap systemd check to pass if either systemd or systemctl are found

[dpritchett]

Closes #1019.

Test log

Ubuntu 24.10 box with systemd installed

Correctly identifies the existence of systemctl.

daniel@dp-rb-jupyterhub:~$ cat /proc/version
Linux version 6.11.0-9-generic (buildd@lcy02-amd64-093) (x86_64-linux-gnu-gcc-14 (Ubuntu 14.2.0-4ubuntu2) 14.2.0, GNU ld (GNU Binutils for Ubuntu) 2.43.1) #9-Ubuntu SMP PREEMPT_DYNAMIC Mon Oct 14 13:19:59 UTC 2024
daniel@dp-rb-jupyterhub:~$ ./check_systemd_exists.test.py
INFO:tljh_test:testing systemd binary locator check	python=3.12.7 (main, Feb  4 2025, 14:46:03) [GCC 14.2.0]
INFO:tljh_test:found at least one of systemctl or systemd
INFO:tljh_test:/usr/bin/systemctl
INFO:tljh_test:None

Darwin box with no systemd

Correctly identifies no systemd present.

> uname -a
Darwin johnny-mnemonic 24.4.0 Darwin Kernel Version 24.4.0: Fri Apr 11 18:33:40 PDT 2025; root:xnu-11417.101.15~117/RELEASE_ARM64_T6031 arm64 arm Darwin

the-littlest-jupyterhub on  djp-adjust-systemd-check [?] via 🐍 v3.12.4
> ./check_systemd_exists.test.py
INFO:tljh_test:testing systemd binary locator check	python=3.12.4 (main, Jul 25 2024, 22:11:22) [Clang 18.1.8 ]
ERROR:tljh_test:did not find either systemctl or systemd

Test script used

Full test script for your reference:

#!/usr/bin/env python3

import sys
import shutil
import logging

logger = logging.getLogger('tljh_test')
logging.basicConfig(stream=sys.stdout, level=logging.DEBUG)


logger.info(f'testing systemd binary locator check\tpython={sys.version}')

if not any([shutil.which("systemctl"), shutil.which("systemd")]):
    logger.error("did not find either systemctl or systemd")
else:
    logger.info("found at least one of systemctl or systemd")
    logger.info(shutil.which("systemctl"))
    logger.info(shutil.which("systemd"))

[manics]

You've added this function, but it's not used

[dpritchett]

Good eye, whoops. I was contemplating breaking out more pieces to test before I noticed you already have an integration test suite running on GitHub Actions. I've stripped that part out, now to see if the other failures are relevant to this PR or not.

[dpritchett]

Switching to Draft until I sort out the build matrix failures

[manics]

The integration tests are flakey, they've passed after a rerun.