Systemd Run for Mise Python Tasks

tasks_lib.py

import contextlib


class SystemdRun:
    def __init__(self, unit_name: str, restart_wait: str = '5s'):
        self.unit_name = unit_name
        self.restart_wait = restart_wait

    def stop(self):
        sub_run('systemctl', '--user', 'stop', self.unit_name, capture=True, check=False)

    def mise_exec(self, *exec_args: list[str]):
        self.stop()

        sub_run(
            'systemd-run',
            '--user',
            '--unit',
            self.unit_name,
            '--working-directory',
            environ['MISE_PROJECT_ROOT'],
            '--property=Restart=on-failure',
            f'--property=RestartSec={self.restart_wait}',
            'mise',
            'exec',
            '--',
            *exec_args,
        )

        try:
            sub_run(
                'journalctl',
                '--user',
                '--follow',
                '--since',
                'now',
                '--unit',
                self.unit_name,
                # --output=cat gives us color codes from the journal so the output for the dev looks
                # like what it would have if they had seen it directly from the process output.
                '--output=cat',
            )
        except KeyboardInterrupt:
            # For some reason, the stop process likes to throw a TERM signal too in this case.
            with contextlib.suppress(KeyboardInterrupt):
                self.stop()

web-server.py

from tasks_lib import SystemdRun


if __name__ == '__main__':
    SystemdRun('poster-web').mise_exec('poster', 'run')

In order to run multiple units at the same time, the code should be adjusted so the log output is an explicit call at the end. So, usage would look more like:

sdr = SystemdRun('poster')
sdr.mise_exec('poster', 'run')
sdr.mise_exec('celery', ...)
sdr.mise_exec('vite', 'run')
sdr.logs()