systemctl

#!/usr/bin/python

import subprocess
import sys
import fcntl

if sys.argv[1] == "is-wrapped":
    print("Yes, this is the wrapped version with locking.")
    sys.exit(0)

REAL_SYSTEMCTL = "/bin/systemctl"

# Determine the necessary lock type.
op = fcntl.LOCK_SH
if sys.argv[1].startswith("daemon-"):
    op = fcntl.LOCK_EX

# Acquire the lock.
fd = open('/tmp/daemon-reload-lock', 'w')
fcntl.flock(fd, op)

# Call the real systemctl with the same arguments.
args = [REAL_SYSTEMCTL] + sys.argv[1:]
code = subprocess.call(args, stdin=sys.stdin, stdout=sys.stdout, stderr=sys.stderr)
sys.exit(code)