mdk/backup.py

   1 #!/usr/bin/env python
   2 # -*- coding: utf-8 -*-
   3
   4 """
   5 Moodle Development Kit
   6
   7 Copyright (c) 2012 Frédéric Massart - FMCorz.net
   8
   9 This program is free software: you can redistribute it and/or modify
  10 it under the terms of the GNU General Public License as published by
  11 the Free Software Foundation, either version 3 of the License, or
  12 (at your option) any later version.
  13
  14 This program is distributed in the hope that it will be useful,
  15 but WITHOUT ANY WARRANTY; without even the implied warranty of
  16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17 GNU General Public License for more details.
  18
  19 You should have received a copy of the GNU General Public License
  20 along with this program.  If not, see <http://www.gnu.org/licenses/>.
  21
  22 http://github.com/FMCorz/mdk
  23 """
  24
  25 import os
  26 import json
  27 import time
  28 import logging
  29 from distutils.dir_util import copy_tree
  30
  31 from .tools import chmodRecursive, mkdir
  32 from .db import DB
  33 from .config import Conf
  34 from .workplace import Workplace
  35 from .exceptions import *
  36
  37 C = Conf()
  38 jason = 'info.json'
  39 sqlfile = 'dump.sql'
  40
  41
  42 class BackupManager(object):
  43
  44     def __init__(self):
  45         self.path = os.path.expanduser(os.path.join(C.get('dirs.moodle'), 'backup'))
  46         if not os.path.exists(self.path):
  47             mkdir(self.path, 0777)
  48
  49     def create(self, M):
  50         """Creates a new backup of M"""
  51
  52         if M.isInstalled() and M.get('dbtype') not in ('mysqli', 'mariadb'):
  53             raise BackupDBEngineNotSupported('Cannot backup database engine %s' % M.get('dbtype'))
  54
  55         name = M.get('identifier')
  56         if name == None:
  57             raise Exception('Cannot backup instance without identifier!')
  58
  59         now = int(time.time())
  60         backup_identifier = self.createIdentifier(name)
  61         Wp = Workplace()
  62
  63         # Copy whole directory, shutil will create topath
  64         topath = os.path.join(self.path, backup_identifier)
  65         path = Wp.getPath(name)
  66         logging.info('Copying instance directory')
  67         copy_tree(path, topath, preserve_symlinks=1)
  68
  69         # Dump the whole database
  70         if M.isInstalled():
  71             logging.info('Dumping database')
  72             dumpto = os.path.join(topath, sqlfile)
  73             fd = open(dumpto, 'w')
  74             M.dbo().selectdb(M.get('dbname'))
  75             M.dbo().dump(fd)
  76         else:
  77             logging.info('Instance not installed. Do not dump database.')
  78
  79         # Create a JSON file containing all known information
  80         logging.info('Saving instance information')
  81         jsonto = os.path.join(topath, jason)
  82         info = M.info()
  83         info['backup_origin'] = path
  84         info['backup_identifier'] = backup_identifier
  85         info['backup_time'] = now
  86         json.dump(info, open(jsonto, 'w'), sort_keys=True, indent=4)
  87
  88         return True
  89
  90     def createIdentifier(self, name):
  91         """Creates an identifier"""
  92         for i in range(1, 100):
  93             identifier = '{0}_{1:0>2}'.format(name, i)
  94             if not self.exists(identifier):
  95                 break
  96             identifier = None
  97         if not identifier:
  98             raise Exception('Could not generate a backup identifier! How many backup did you do?!')
  99         return identifier
 100
 101     def exists(self, name):
 102         """Checks whether a backup exists under this name or not"""
 103         d = os.path.join(self.path, name)
 104         f = os.path.join(d, jason)
 105         if not os.path.isdir(d):
 106             return False
 107         return os.path.isfile(f)
 108
 109     def get(self, name):
 110         return Backup(self.getPath(name))
 111
 112     def getPath(self, name):
 113         return os.path.join(self.path, name)
 114
 115     def list(self):
 116         """Returns a list of backups with their information"""
 117         dirs = os.listdir(self.path)
 118         backups = {}
 119         for name in dirs:
 120             if name == '.' or name == '..': continue
 121             if not self.exists(name): continue
 122             try:
 123                 backups[name] = Backup(self.getPath(name))
 124             except:
 125                 # Must successfully retrieve information to be a valid backup
 126                 continue
 127         return backups
 128
 129
 130 class Backup(object):
 131
 132     def __init__(self, path):
 133         self.path = path
 134         self.jason = os.path.join(path, jason)
 135         self.sqlfile = os.path.join(path, sqlfile)
 136         if not os.path.isdir(path):
 137             raise Exception('Could not find backup in %s' % path)
 138         elif not os.path.isfile(self.jason):
 139             raise Exception('Backup information file unfound!')
 140         self.load()
 141
 142     def get(self, name):
 143         """Returns a info on the backup"""
 144         try:
 145             return self.infos[name]
 146         except:
 147             return None
 148
 149     def load(self):
 150         """Loads the backup information"""
 151         if not os.path.isfile(self.jason):
 152             raise Exception('Backup information file not found!')
 153         try:
 154             self.infos = json.load(open(self.jason, 'r'))
 155         except:
 156             raise Exception('Could not load information from JSON file')
 157
 158     def restore(self, destination=None):
 159         """Restores the backup"""
 160
 161         identifier = self.get('identifier')
 162         if not identifier:
 163             raise Exception('Identifier is invalid! Cannot proceed.')
 164
 165         Wp = Workplace()
 166         if destination == None:
 167             destination = self.get('backup_origin')
 168         if not destination:
 169             raise Exception('Wrong path to perform the restore!')
 170
 171         if os.path.isdir(destination):
 172             raise BackupDirectoryExistsException('Destination directory already exists!')
 173
 174         # Restoring database
 175         if self.get('installed') and os.path.isfile(self.sqlfile):
 176             dbname = self.get('dbname')
 177             dbo = DB(self.get('dbtype'), C.get('db.%s' % self.get('dbtype')))
 178             if dbo.dbexists(dbname):
 179                 raise BackupDBExistsException('Database already exists!')
 180
 181         # Copy tree to destination
 182         try:
 183             logging.info('Restoring instance directory')
 184             copy_tree(self.path, destination, preserve_symlinks=1)
 185             M = Wp.get(identifier)
 186             chmodRecursive(Wp.getPath(identifier, 'data'), 0777)
 187         except Exception as e:
 188             raise Exception('Error while restoring directory\n%s\nto %s. Exception: %s' % (self.path, destination, e))
 189
 190         # Restoring database
 191         if self.get('installed') and os.path.isfile(self.sqlfile):
 192             logging.info('Restoring database')
 193             content = ''
 194             f = open(self.sqlfile, 'r')
 195             for l in f:
 196                 content += l
 197             queries = content.split(';\n')
 198             content = None
 199             logging.info("%d queries to execute" % (len(queries)))
 200
 201             dbo.createdb(dbname)
 202             dbo.selectdb(dbname)
 203             done = 0
 204             for query in queries:
 205                 if len(query.strip()) == 0: continue
 206                 try:
 207                     dbo.execute(query)
 208                 except:
 209                     logging.error('Query failed! You will have to fix this mually. %s', query)
 210                 done += 1
 211                 if done % 500 == 0:
 212                     logging.debug("%d queries done" % done)
 213             logging.info('%d queries done' % done)
 214             dbo.close()
 215
 216         # Restoring symbolic link
 217         linkDir = os.path.join(Wp.www, identifier)
 218         wwwDir = Wp.getPath(identifier, 'www')
 219         if os.path.islink(linkDir):
 220             os.remove(linkDir)
 221         if os.path.isfile(linkDir) or os.path.isdir(linkDir):  # No elif!
 222             logging.warning('Could not create symbolic link. Please manually create: ln -s %s %s' % (wwwDir, linkDir))
 223         else:
 224             os.symlink(wwwDir, linkDir)
 225
 226         return M