#!/usr/bin/python2
import os, sys, stat, signal, errno

pid = None
status = None

def listdir(path):
	try:
		result = os.stat(path)
	except OSError:
		return []
	if stat.S_ISDIR(result.st_mode):
		return sorted(os.listdir(path))
	else:
		return []

def is_exe(path):
	try:
		return os.path.isfile(path) and os.access(path, os.X_OK)
	except OSError:
		return False

def reap_child(signum, frame):
	global pid, status, waiting_for_runit
	try:
		result = os.wait3(os.WNOHANG)
		if result is not None and pid == result[0]:
			status = result[1]
	except OSError:
		pass

def stop_child_process(name):
	global pid
	print("*** Shutting down %s (PID %d)..." % (name, pid))
	try:
		os.kill(pid, signal.SIGHUP)
	except OSError:
		pass

def run_command_killable(*argv):
	global pid
	filename = argv[0]
	pid = os.spawnvp(os.P_NOWAIT, filename, argv)
	signal.signal(signal.SIGINT, lambda signum, frame: stop_child_process(filename))
	signal.signal(signal.SIGTERM, lambda signum, frame: stop_child_process(filename))
	try:
		this_pid, status = os.waitpid(pid, 0)
	except OSError as e:
		if e.errno == errno.EINTR:
			sys.exit(2)
		else:
			raise
	finally:
		signal.signal(signal.SIGINT, signal.SIG_DFL)
		signal.signal(signal.SIGTERM, signal.SIG_DFL)
	if status != 0:
		sys.stderr.write("*** %s failed with exit code %d\n" % (filename, status))
		sys.exit(1)

# Run /etc/my_init.d/*
for name in listdir("/etc/my_init.d"):
	filename = "/etc/my_init.d/" + name
	if is_exe(filename):
		print("*** Running %s..." % filename)
		run_command_killable(filename)

# Run /etc/rc.local.
if is_exe("/etc/rc.local"):
	print("*** Running /etc/rc.local...")
	run_command_killable("/etc/rc.local")

# Start runit.
signal.signal(signal.SIGCHLD, reap_child)
print("*** Booting runit...")
pid = os.spawnl(os.P_NOWAIT, "/usr/bin/runsvdir", "/usr/bin/runsvdir", "-P", "/etc/service", "log: %s" % ('.' * 395))
print("*** Runit started as PID %d" % pid)
signal.signal(signal.SIGTERM, lambda signum, frame: stop_child_process("runit"))

# Wait for runit, and while waiting, reap any adopted orphans.
done = False
while not done:
	try:
		this_pid, status = os.waitpid(pid, 0)
		done = True
	except OSError as e:
		if e.errno == errno.EINTR:
			# Try again
			pass
		else:
			# The SIGCHLD handler probably caught it.
			done = True

# Runit has exited. Reset signal handlers.
print("*** Runit exited with code %s. Waiting for all services to shut down..." % status)
signal.signal(signal.SIGCHLD, signal.SIG_DFL)
signal.signal(signal.SIGTERM, signal.SIG_DFL)
signal.siginterrupt(signal.SIGCHLD, False)
signal.siginterrupt(signal.SIGTERM, False)

# Wait at most 5 seconds for services to shut down.
import time

def shutdown(signum = None, frame = None):
	global status
	if status is not None:
		sys.exit(status)

signal.signal(signal.SIGALRM, shutdown)
signal.alarm(5)
done = False
while not done:
	done = os.system("/usr/bin/sv status /etc/service/* | grep -q '^run:'") != 0
	if not done:
		time.sleep(0.5)
shutdown()