Invoke rsync using python/cron

pysync.py

#!/usr/bin/env python
import subprocess
import fcntl
import os

if __name__=="__main__":

	lockFina = "docslock"
	fullLockFina = os.path.join(os.path.dirname(os.path.realpath(__file__)), lockFina)

	if not os.path.exists(fullLockFina):
		fi = open(fullLockFina, "w")
	else:
		fi = open(fullLockFina, "r")

	#Try to get exclusive lock, quit if this fails
	#This stops multiple instances of rsync running at the same time
	fcntl.flock(fi, fcntl.LOCK_EX | fcntl.LOCK_NB)

	# https://stackoverflow.com/a/18482169/4288232
	subprocess.call(["rsync", "-avz", "-delete", "-e", "ssh", "/home/user/Documents/", "user@nas:/path/to/backup"])