vmmgr/usr/lib/python3.6/lxcmgr/svcmgr.py

# -*- coding: utf-8 -*-

import os
import subprocess

from .paths import AUTOSTART_SVC_DIR, SERVICE_DIR, STARTED_SVC_DIR
from .templates import SERVICE

def lxcize(service):
    # Prepend lxc- to service name, otherwise there's much greater risk of naming conflict with other host services
    return 'lxc-{}'.format(service)

def create_service(container, image):
    depends = ' '.join([lxcize(service) for service in image['depends']]) if 'depends' in image else ''
    # Add ready check to start_post
    # This could arguably be done better via some template engine, but introducing one for a single template file seems like an overkill
    start_post = '\nstart_post() {{\n    timeout -t 60 lxc-attach {} -- sh -c \'until {}; do sleep 0.1; done\'\n}}\n'.format(container, image['ready']) if 'ready' in image else ''
    service_file = os.path.join(SERVICE_DIR, lxcize(container))
    with open(service_file, 'w') as f:
        f.write(SERVICE.format(container=container, depends=depends, start_post=start_post))
    os.chmod(service_file, 0o755)
    update_services()

def delete_service(service):
    if is_service_started(service):
        stop_service(service)
    if is_service_autostarted(service):
        update_service_autostart(service, False)
    try:
        os.unlink(os.path.join(SERVICE_DIR, lxcize(service)))
        update_services()
    except FileNotFoundError:
        pass

def update_services():
    subprocess.run(['/sbin/rc-update', '-u'], check=True)

def start_service(service):
    if not is_service_started(service):
        subprocess.run(['/sbin/service', lxcize(service), 'start'], check=True)

def stop_service(service):
    if is_service_started(service):
        subprocess.run(['/sbin/service', lxcize(service), 'stop'], check=True)

def is_service_started(service):
    # Check OpenRC service status without calling any binary
    return os.path.exists(os.path.join(STARTED_SVC_DIR, lxcize(service)))

def is_service_autostarted(service):
    # Check OpenRC service enablement
    return os.path.exists(os.path.join(AUTOSTART_SVC_DIR, lxcize(service)))

def update_service_autostart(service, enabled):
    # Add/remove the service to/from OpenRC default runlevel
    subprocess.run(['/sbin/rc-update', 'add' if enabled else 'del', lxcize(service)])