backup

#!/usr/bin/python3
# Script to backup selected folders, made for cron
# By Trent Arcuri, 2019
import argparse
import time
import distutils.spawn
import os
import socket
import subprocess
import sys

# Test if running as root, if not, attemp a respawn using sudo
if os.geteuid() != 0:
    print('This program requires root access, trying sudo')
    os.execvp("sudo", ["sudo"] + sys.argv)

# Gather command line arguments
parser = argparse.ArgumentParser()
parser.add_argument('-s', '--sleep',
                    type=str, dest='warningseconds', default='10',
                    help='Specify seconds to show warning before continuing')
parser.add_argument('-n', '--name',
                    type=str, dest='backupname', default=socket.gethostname(),
                    help='Specify name for this backup')
parser.add_argument('-t', '--target',
                    type=str, dest='backuptarget', default='/',
                    help='Specify what to backup')
parser.add_argument('-d', '--directory',
                    type=str, dest='backupdir', default='/mnt/backup/',
                    help='Specify where to backup to')
parser.add_argument('-i', '--increment',
                    dest='increment', action='store_true', default=False,
                    help='Run an incremental backup')
parser.add_argument('-m', '--maxincrement',
                    type=int, dest='backupincmax', default=3,
                    help='Run an incremental backup')
args = parser.parse_args()
# Format/shorten arguments into sane variables
# Rsync copies here in the end
finalpath = args.backupdir + args.backupname + '/'
# When the script was called
launchtime = time.time()
humanlaunchtime = time.strftime("%Y-%m-%d %H:%M:%S")
# Rsync command sanitization
rsync = distutils.spawn.find_executable('rsync')
rsyncexcludearg = '--exclude='
rsyncoptions = ['-Pauvr', '--delete']
exclude = ["/dev/*",
           "/proc/*",
           "/sys/*",
           "/tmp/*",
           "/run/*",
           "/mnt/*",
           "/media/*",
           "/lost+found"]
# Add rsyncexcludearg before every exclude listed above
rsyncexclude = [rsyncexcludearg + excludeitem for excludeitem in exclude]
rsyncargs = rsyncoptions + rsyncexclude
rsynccommand = [rsync] + rsyncargs + [args.backuptarget, finalpath]


def banner():
    # Print some info about what is going to run
    print("Backup running at", humanlaunchtime, "\n",
          "Backup target:", args.backuptarget, "\n",
          "Output directory:", args.backupdir, "\n",
          "Backup name:", args.backupname, "\n",
          "Maximum increments:", args.backupincmax, "\n",
          "Warning timeout:", args.warningseconds, "\n",
          "Increment mode:", args.increment)


def cleanup():
    # Gather time as of completion, print, and increment if necessary
    humanendtime = time.strftime("%Y-%m-%d %H:%M:%S")
    print('Backup completed, cleaning up')
    if args.increment:
        incrementprebackup()
    os.utime(args.backupdir + args.backupname, (launchtime, launchtime))
    print(args.backupname, "backup stopped at", humanendtime)


def incrementprebackup():
    # Test if any backups are older than X days, if so, delete //DESTRUCTIVE//
    print('Deleting backups older than', args.backupincmax, 'days:')
    for backup in os.listdir(args.backupdir + args.backuptarget):
        backup = args.backupdir + args.backuptarget + '/' + backup
        if os.stat(backup).st_mtime < launchtime - args.backupincmax * 86400:
            os.remove(backup)
        print('Deleted', backup)


def rsyncbackup():
    # Run the backup process here, print command for log usage/debugging
    print("Running", rsynccommand)
    subprocess.call(rsynccommand)


def main():
    # Main program entry point, call preliminary functions
    banner()
    # Test if xmessage is installed, if so, show a warning message
    if distutils.spawn.find_executable("xmessage") is not None:
        print('Xmessage found, launching warning message')
        warning = subprocess.call(["xmessage", "-timeout", args.warningseconds,
                                   "-nearmous",
                                   "-buttons", "run,cancel",
                                   "Performing backup in", args.warningseconds,
                                   "seconds."])
    else:
        # This is necessary in case the program is run headlessly (e.g. ssh)
        warning = 101
    if warning == 102:
        print('User cancelled backup.')
        # Note this behaviour, an incremental cleanup is still performed
        cleanup()
        quit(1)
    print('Running backup')
    # Begin backup, after tests
    rsyncbackup()
    cleanup()


# Call main function
main()