threepress: open source software for publishers

I’m sure everyone has one of these lying around, but here’s mine in case you are as lazy a programmer as I usually am.  The only thing Django-specific about it is that it reads your database configuration directly out of your settings file.

If you run this via cron it will automatically create its backup directory and a zipped SQL dump with the name of the current day of the week.  If one already exists, it simply overwrites it.  This means you’ll have a week’s worth of daily rolling backups.  If you need more granularity, add a timestamp to the datestamp.  If you need more persistent backups, switch to a full date scheme.

The latest version of this can always been found here.

#!/usr/bin/env python

import sys
import os.path
import os
import logging
from datetime import datetime
from settings import DATABASE_NAME, DATABASE_USER, DATABASE_PASSWORD

logging.basicConfig(level=logging.WARN)

BACKUP_DIR = "%s/backups" % os.path.dirname(__file__)
MYSQL_CMD = 'mysqldump'
ZIP_CMD = 'zip'

def _setup():
   if not os.path.exists(BACKUP_DIR):
       logging.debug("Created backup directory %s" % BACKUP_DIR)
       os.mkdir(BACKUP_DIR)
   else:
       logging.debug("Using backup directory %s" % BACKUP_DIR)

def _backup_name():
   now = datetime.now()
   day_name = now.strftime("%A")
   file_name = "%s.sql" % day_name.lower()
   logging.debug("Setting backup name for day name %s as %s" % (day_name, file_name))
   return file_name

def _run_backup(file_name):
   cmd = "%(mysqldump)s -u %(user)s --password=%(password)s %(database)s > %(log_dir)s/%(file)s" % {
       'mysqldump' : MYSQL_CMD,
       'user' : DATABASE_USER,
       'password' : DATABASE_PASSWORD,
       'database' : DATABASE_NAME,
       'log_dir' : BACKUP_DIR,
       'file': file_name}
   logging.debug("Backing up with command %s " % cmd)
   return os.system(cmd)

def _zip_backup(file_name):
   backup = "%s/%s" % (BACKUP_DIR, file_name)
   zipfile_name = "%s.zip" % (backup)

   if os.path.exists(zipfile_name):
       logging.debug("Removing previous zip archive %s" % zipfile_name)
       os.remove(zipfile_name)
   zip_cmds = {'zip' : ZIP_CMD, 'zipfile' : zipfile_name, 'file' : backup }

   # Create the backup
   logging.debug("Making backup as %s " % zipfile_name)
   os.system("%(zip)s -q -9 %(zipfile)s %(file)s" % zip_cmds)

   # Test our archive
   logging.debug("Testing zip archive")
   if not os.system("%(zip)s -T -D -q %(zipfile)s" % zip_cmds):
       # If there was no problem, then delete the unzipped version
       os.remove(backup)
       return True
   else:
       return False

def main(*args):
   _setup()
   file_name = _backup_name()
   _run_backup(file_name)
   return(_zip_backup(file_name))

if __name__ == '__main__':
   sys.exit(main(*sys.argv))