ansible/library/database/mysql_variables
Maykel Moya b90a250165 Improve change detection in mysql_variables
mysql_variables bindly executes a SET var = value query even when
the variable already has the requested value.

With this patch the query is executed only if the current value is
different to the requested one.
2013-10-17 19:13:58 +02:00

214 lines
6.6 KiB
Python

#!/usr/bin/python
# -*- coding: utf-8 -*-
"""
Ansible module to manage mysql variables
(c) 2013, Balazs Pocze <banyek@gawker.com>
Certain parts are taken from Mark Theunissen's mysqldb module
This file is part of Ansible
Ansible is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
Ansible is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with Ansible. If not, see <http://www.gnu.org/licenses/>.
"""
DOCUMENTATION = '''
---
module: mysql_variables
short_description: Manage MySQL global variables
description:
- Query / Set MySQL variables
version_added: 1.3
options:
variable:
description:
- Variable name to operate
required: True
value:
description:
- If set, then sets variable value to this
required: False
login_user:
description:
- username to connect mysql host, if defined login_password also needed.
required: False
login_password:
description:
- password to connect mysql host, if defined login_user also needed.
required: False
login_host:
description:
- mysql host to connect
required: False
login_unix_socket:
description:
- unix socket to connect mysql server
'''
EXAMPLES = '''
# Check for sync_binary_log setting
- mysql_variables: variable=sync_binary_log
# Set read_only variable to 1
- mysql_variables: variable=read_only value=1
'''
import ConfigParser
import os
import warnings
try:
import MySQLdb
except ImportError:
mysqldb_found = False
else:
mysqldb_found = True
def getvariable(cursor, mysqlvar):
cursor.execute("SHOW VARIABLES LIKE '" + mysqlvar + "'")
mysqlvar_val = cursor.fetchall()
return mysqlvar_val
def setvariable(cursor, mysqlvar, value):
try:
cursor.execute("SET GLOBAL " + mysqlvar + "=" + value)
cursor.fetchall()
result = True
except Exception, e:
result = str(e)
return result
def strip_quotes(s):
""" Remove surrounding single or double quotes
>>> print strip_quotes('hello')
hello
>>> print strip_quotes('"hello"')
hello
>>> print strip_quotes("'hello'")
hello
>>> print strip_quotes("'hello")
'hello
"""
single_quote = "'"
double_quote = '"'
if s.startswith(single_quote) and s.endswith(single_quote):
s = s.strip(single_quote)
elif s.startswith(double_quote) and s.endswith(double_quote):
s = s.strip(double_quote)
return s
def config_get(config, section, option):
""" Calls ConfigParser.get and strips quotes
See: http://dev.mysql.com/doc/refman/5.0/en/option-files.html
"""
return strip_quotes(config.get(section, option))
def load_mycnf():
config = ConfigParser.RawConfigParser()
mycnf = os.path.expanduser('~/.my.cnf')
if not os.path.exists(mycnf):
return False
try:
config.readfp(open(mycnf))
except (IOError):
return False
# We support two forms of passwords in .my.cnf, both pass= and password=,
# as these are both supported by MySQL.
try:
passwd = config_get(config, 'client', 'password')
except (ConfigParser.NoOptionError):
try:
passwd = config_get(config, 'client', 'pass')
except (ConfigParser.NoOptionError):
return False
# If .my.cnf doesn't specify a user, default to user login name
try:
user = config_get(config, 'client', 'user')
except (ConfigParser.NoOptionError):
user = getpass.getuser()
creds = dict(user=user, passwd=passwd)
return creds
def main():
module = AnsibleModule(
argument_spec = dict(
login_user=dict(default=None),
login_password=dict(default=None),
login_host=dict(default="localhost"),
login_unix_socket=dict(default=None),
variable=dict(default=None),
value=dict(default=None)
)
)
user = module.params["login_user"]
password = module.params["login_password"]
host = module.params["login_host"]
mysqlvar = module.params["variable"]
value = module.params["value"]
if not mysqldb_found:
module.fail_json(msg="the python mysqldb module is required")
else:
warnings.filterwarnings('error', category=MySQLdb.Warning)
# Either the caller passes both a username and password with which to connect to
# mysql, or they pass neither and allow this module to read the credentials from
# ~/.my.cnf.
login_password = module.params["login_password"]
login_user = module.params["login_user"]
if login_user is None and login_password is None:
mycnf_creds = load_mycnf()
if mycnf_creds is False:
login_user = "root"
login_password = ""
else:
login_user = mycnf_creds["user"]
login_password = mycnf_creds["passwd"]
elif login_password is None or login_user is None:
module.fail_json(msg="when supplying login arguments, both login_user and login_password must be provided")
try:
if module.params["login_unix_socket"]:
db_connection = MySQLdb.connect(host=module.params["login_host"], unix_socket=module.params["login_unix_socket"], user=login_user, passwd=login_password, db="mysql")
else:
db_connection = MySQLdb.connect(host=module.params["login_host"], user=login_user, passwd=login_password, db="mysql")
cursor = db_connection.cursor()
except Exception, e:
module.fail_json(msg="unable to connect to database, check login_user and login_password are correct or ~/.my.cnf has the credentials")
if mysqlvar is None:
module.fail_json(msg="Cannot run without variable to operate with")
mysqlvar_val = getvariable(cursor, mysqlvar)
if value is None:
module.exit_json(msg=mysqlvar_val)
else:
if value == mysqlvar_val[0][1]:
module.exit_json(msg="Variable already set to requested value", changed=False)
result = setvariable(cursor, mysqlvar, value)
if result is True:
module.exit_json(msg="Variable change succeeded", changed=True)
else:
module.fail_json(msg=result, changed=False)
# this is magic, see lib/ansible/module_common.py
#<<INCLUDE_ANSIBLE_MODULE_COMMON>>
main()