python/google/appengine/api/rdbms_mysqldb.py

   1 #!/usr/bin/env python
   2 #
   3 # Copyright 2007 Google Inc.
   4 #
   5 # Licensed under the Apache License, Version 2.0 (the "License");
   6 # you may not use this file except in compliance with the License.
   7 # You may obtain a copy of the License at
   8 #
   9 #     http://www.apache.org/licenses/LICENSE-2.0
  10 #
  11 # Unless required by applicable law or agreed to in writing, software
  12 # distributed under the License is distributed on an "AS IS" BASIS,
  13 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  14 # See the License for the specific language governing permissions and
  15 # limitations under the License.
  16 #
  17
  18
  19
  20
  21 """Relational database API stub that uses the MySQLdb DB-API library.
  22
  23 Also see the rdbms module.
  24 """
  25
  26
  27
  28
  29
  30
  31
  32
  33 import logging
  34 import os
  35
  36 _POTENTIAL_SOCKET_LOCATIONS = (
  37     '/tmp/mysql.sock',
  38     '/var/run/mysqld/mysqld.sock',
  39     '/var/lib/mysql/mysql.sock',
  40     '/var/run/mysql/mysql.sock',
  41     '/var/mysql/mysql.sock',
  42     )
  43
  44
  45 _connect_kwargs = {}
  46
  47
  48
  49 _OS_NAME = os.name
  50
  51
  52 def SetConnectKwargs(**kwargs):
  53   """Sets the keyword args (host, user, etc) to pass to MySQLdb.connect()."""
  54
  55   global _connect_kwargs
  56   _connect_kwargs = dict(kwargs)
  57
  58
  59 def FindUnixSocket():
  60   """Find the Unix socket for MySQL by scanning some known locations.
  61
  62   Returns:
  63     If found, the path to the Unix socket, otherwise, None.
  64   """
  65   for path in _POTENTIAL_SOCKET_LOCATIONS:
  66     if os.path.exists(path):
  67       return path
  68
  69
  70 try:
  71   import google
  72   import MySQLdb
  73
  74   from MySQLdb import *
  75
  76
  77
  78   __import__('MySQLdb.constants', globals(), locals(), ['*'])
  79 except ImportError:
  80
  81   def connect(instance=None, database=None):
  82     logging.error('The rdbms API (Google Cloud SQL) is not available because '
  83                   'the MySQLdb library could not be loaded. Please see the SDK '
  84                   'documentation for installation instructions.')
  85
  86     raise NotImplementedError('Unable to find the MySQLdb library')
  87 else:
  88
  89
  90   def connect(instance=None, database=None, **kwargs):
  91     merged_kwargs = _connect_kwargs.copy()
  92     if database:
  93       merged_kwargs['db'] = database
  94     merged_kwargs.update(kwargs)
  95     if 'password' in merged_kwargs:
  96       merged_kwargs['passwd'] = merged_kwargs.pop('password')
  97     host = merged_kwargs.get('host')
  98     if ((not host or host == 'localhost') and
  99         not merged_kwargs.get('unix_socket') and
 100         _OS_NAME == 'posix'):
 101
 102
 103
 104
 105
 106
 107
 108
 109
 110
 111       socket = FindUnixSocket()
 112       if socket:
 113         merged_kwargs['unix_socket'] = socket
 114       else:
 115         logging.warning(
 116             'Unable to find MySQL socket file.  Use --mysql_socket to '
 117             'specify its location manually.')
 118     logging.info('Connecting to MySQL with kwargs %r', merged_kwargs)
 119     try:
 120       return MySQLdb.connect(**merged_kwargs)
 121     except MySQLdb.Error:
 122       logging.critical(
 123           'MySQL connection failed! Ensure that you have provided correct '
 124           'values for the --mysql_* flags when running dev_appserver.py')
 125       raise
 126
 127
 128 def set_instance(instance):
 129   logging.info('set_instance() is a noop in dev_appserver.')