frappe/py/webnotes/utils/backups.py

# Copyright (c) 2012 Web Notes Technologies Pvt Ltd (http://erpnext.com)
# 
# MIT License (MIT)
# 
# Permission is hereby granted, free of charge, to any person obtaining a 
# copy of this software and associated documentation files (the "Software"), 
# to deal in the Software without restriction, including without limitation 
# the rights to use, copy, modify, merge, publish, distribute, sublicense, 
# and/or sell copies of the Software, and to permit persons to whom the 
# Software is furnished to do so, subject to the following conditions:
# 
# The above copyright notice and this permission notice shall be included in 
# all copies or substantial portions of the Software.
# 
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, 
# INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A 
# PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT 
# HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF 
# CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE 
# OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
# 

"""
	This module handles the On Demand Backup utility
	
	To setup in defs set: 
		backup_path: path where backups will be taken (for eg /backups)
		backup_link_path: download link for backups (eg /var/www/wnframework/backups)
		backup_url: base url of the backup folder (eg http://mysite.com/backups)
"""
#Imports
import os, webnotes
from datetime import datetime


#Global constants
from webnotes.defs import backup_path, backup_link_path
verbose = 0

#-------------------------------------------------------------------------------
class BackupGenerator:
	"""
		This class contains methods to perform On Demand Backup
		
		To initialize, specify (db_name, user, password, db_file_name=None)
		If specifying db_file_name, also append ".sql.gz"
	"""
	def __init__(self, db_name, user, password, db_file_name=None):
		self.db_name = db_name.replace('$', '\$')
		self.user = user
		self.password = password
		self.db_file_name = db_file_name and db_file_name \
							or (os.path.join(backup_path, self.db_name + ".sql.gz"))

	def take_dump(self):
		"""
			Dumps a db via mysqldump
		"""
		os.system("""mysqldump -u %(user)s -p%(password)s %(db_name)s | 
					 gzip -c > %(db_file_name)s""" % self.__dict__)
	
	
	def copy_to_backup_link(self):
		"""
			Copies the backup file from backup path to shared link path
			It also gives the file a random name, thus hiding the db_name
		"""
		import random
		todays_date = "".join(str(datetime.date(datetime.today())).split("-"))
		random_number = str(int(random.random()*99999999))
		
		#Generate a random name using today's date and a 8 digit random number
		random_name = todays_date + "_" + random_number + ".sql.gz"
		
		os.system("""cp -f %(src_file)s %(dest_file)s""" % \
					{"src_file":self.db_file_name,
					 "dest_file":os.path.join(backup_link_path, random_name)})
		if verbose: print "file copied"
		return random_name
	
	
	def get_recipients(self):
		"""
			Get recepient's email address
		"""
		#import webnotes.db
		#webnotes.conn = webnotes.db.Database(use_default=1)
		recipient_list = webnotes.conn.sql(\
				   """SELECT parent FROM tabUserRole 
					  WHERE role='System Manager' 
					  AND parent!='Administrator' 
					  AND parent IN 
							 (SELECT email FROM tabProfile WHERE enabled=1)""")
		return [i[0] for i in recipient_list]
		
		
	def send_email(self, backup_file):
		"""
			Sends the link to backup file located at erpnext/backups
		"""
		if hasattr(webnotes.defs, 'backup_url'):
			backup_url = webnotes.defs.backup_url
		else:
			backup_url = webnotes.conn.get_value('Website Settings',
				'Website Settings', 'subdomain') or ''
		file_url = os.path.join(backup_url, backup_file)
		from webnotes.utils.email_lib import sendmail
		
		recipient_list = self.get_recipients()
		msg = """<a href=%(file_url)s>Click here to begin downloading\
		 your backup</a>
		 
		 This link will be valid for 24 hours.
		 
		 Also, a new backup will be available for download (if requested)\
		  only after 24 hours.""" % {"file_url":file_url}
		
		datetime_str = datetime.fromtimestamp(os.stat(self.db_file_name.replace('\$', '$')).st_ctime)
		
		subject = datetime_str.strftime("%d/%m/%Y %H:%M:%S") + """ - Backup ready to be downloaded"""
		sendmail(recipients=recipient_list, msg=msg, subject=subject)
		return recipient_list
		
		
	def get_backup(self):
		"""
			Takes a new dump if existing file is old
			and sends the link to the file as email
		"""
		#Check if file exists and is less than a day old
		#If not Take Dump
		if is_file_old(self.db_file_name):
			self.take_dump()
					
		#Copy file to backup_link_path
		#This is a security hole. When the user calls get_backup repeatedly
		#a file will be generated each time.
		backup_file = self.copy_to_backup_link()		

		#Email Link
		recipient_list = self.send_email(backup_file)
		
		return recipient_list
		
@webnotes.whitelist()
def get_backup():
	"""
		This function is executed when the user clicks on 
		Toos > Download Backup
	"""
	#if verbose: print webnotes.conn.cur_db_name + " " + webnotes.defs.db_password
	odb = BackupGenerator(webnotes.conn.cur_db_name, webnotes.conn.cur_db_name,\
						  get_db_password(webnotes.conn.cur_db_name))
	recipient_list = odb.get_backup()
	delete_temp_backups()
	webnotes.msgprint("""A download link to your backup will be emailed \
	to you shortly on the following email address:
	%s""" % (', '.join(recipient_list)))


def get_db_password(db_name):
	"""
		Get db password from defs
	"""
	from webnotes import defs
	if hasattr(defs, 'get_db_password'):
		return defs.get_db_password(db_name)

	if hasattr(defs, 'db_password'):
		return defs.db_password



def delete_temp_backups():
	"""
		Cleans up the backup_link_path directory by deleting files older than 24 hours
	"""
	file_list = os.listdir(backup_link_path)
	for this_file in file_list:
		this_file_path = os.path.join(backup_link_path, this_file)
		if is_file_old(this_file_path):
			os.remove(this_file_path)


def is_file_old(db_file_name, older_than=24):
		"""
			Checks if file exists and is older than specified hours
			Returns ->
			True: file does not exist or file is old
			False: file is new
		"""		
		if os.path.isfile(db_file_name):
			from datetime import timedelta
			import time
			#Get timestamp of the file
			file_datetime = datetime.fromtimestamp\
						(os.stat(db_file_name).st_ctime)
			if datetime.today() - file_datetime >= timedelta(hours = older_than):
				if verbose: print "File is old"
				return True
			else:
				if verbose: print "File is recent"
				return False
		else:
			if verbose: print "File does not exist"
			return True		

#-------------------------------------------------------------------------------
		
if __name__ == "__main__":
	"""
		is_file_old db_name user password
		get_backup  db_name user password
	"""
	import sys
	cmd = sys.argv[1]
	if cmd == "is_file_old":
		odb = BackupGenerator(sys.argv[2], sys.argv[3], sys.argv[4])
		is_file_old(odb.db_file_name)
	
	if cmd == "get_backup":
		odb = BackupGenerator(sys.argv[2], sys.argv[3], sys.argv[4])
		odb.get_backup()

	if cmd == "take_dump":
		odb = BackupGenerator(sys.argv[2], sys.argv[3], sys.argv[4])
		odb.take_dump()
		
	if cmd == "send_email":
		odb = BackupGenerator(sys.argv[2], sys.argv[3], sys.argv[4])
		odb.send_email("abc.sql.gz")
		
	if cmd == "delete_temp_backups":
		delete_temp_backups()