systemd-test

#!/usr/bin/env python3

import os
import socket

cwd = os.path.dirname(__file__)
LAUNCH = 'httpd-true'

if __name__ == "__main__":
    # Bind a TCP/ip socket
    s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    # Tell the OS to allow instant reuse of the socket
    s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
    s.bind(('localhost', 8080))
    # We don't listen to the socket yet. We just prepare it for another
    # application
    fd = s.fileno()
    # Clone the FD as 3
    # 0 == stdin
    # 1 == stdout
    # 2 == stderr
    # Extra fd start from there.
    os.dup2(fd, 3)
    pid = os.fork()
    if pid == 0:  # In child
        pid = os.getpid()
        print("Child pid = %s" % pid)
        os.environ['LISTEN_PID'] = str(pid)
        os.execv(os.path.join(cwd, LAUNCH), [LAUNCH])

    # In parent, we just wait
    ret = os.waitpid(pid, 0)
    print("Execed child returned %s" % (ret,))