Back up MYSQL database using Python

For work needs, I backed up the company's MYSQL database. I just started learning Python. I watched a set of simple Python teaching videos and simply wrote a backup script. I personally expressed my interest in Python's classes, functions, and build-in functions. , private variables, global variables, etc., I have no idea how to use them, when to use them, etc. I just record them here. I also welcome passing pythoners to give me advice.

Some issues known to me:

1. The script must require all behaviors in the mysql configuration file to be in the key=value format, and there must be no redundant comments. Otherwise, the ConfigParser module will make an error when parsing the configuration file. Due to lack of research I wonder if ConfigParser has a fault-tolerant method that can be called, and I don’t have time to write fault-tolerant processing. Instead, I solved it by sorting out the my.ini configuration file to make it meet the requirements of ConfigParser. The mysql configuration file I use will be attached later.

2. Extensive use of class private member variables, because I don’t know when python variables, class methods, etc. should be privatized, and what the difference is. I only know that when class private member variables are imported or inherited in other scripts, is invisible.

3. There are a lot of file operations and value transfer operations. Currently, we only ensure that there is no problem in passing values ​​in the correct format, and no redundant fault tolerance processing is done. 4. A lot of string splicing is being done. It is my first time to write an operation and maintenance related script. Since I need to call system commands and pass many parameters, I don’t know the subprocess module. I don’t know how others write operation and maintenance scripts, so I just write it directly. Spliced.

5. Other unknown bugs, undiscovered logical errors, etc.

Environment:

- Server: Dell PowerEdge T110

- OS: CentOS 6.3_x86_64

- PythonVersion: 2.7.3

- : 5.5.28 linux x86_64

MysqlBackupScript.py

#!/usr/bin/env python
# coding: utf8
# script MysqlBackupScript
# by Becareful
# version v1.0

"""
This scripts provides auto backup mysql(version == 5.5.x) database .
"""

import os
import sys
import datetime         #用于生成备份文件的日期
import linecache        #用于读取文件的指定行
import ConfigParser     #解析mysql配置文件


class DatabaseArgs(object):
    """

    """

    __MYSQL_BASE_DIR = r'/usr/local/mysql'            #mysql安装目录
    __MYSQL_BIN_DIR = __MYSQL_BASE_DIR + '/bin'       #mysql二进制目录
    __MYSQL_CONFIG_FILE = r'/usr/local/mysql/my.cnf'  #mysql配置文件

    __ONEDAY = datetime.timedelta(days=1)             #一天的时长，用于计算下面的前一天和后一天日期
    __TODAY = datetime.date.today()      #当天日期格式为 YYYY-MM-DD
    __YESTERDAY = __TODAY - __ONEDAY                  #计算昨天日期
    __TOMORROW = __TODAY + __ONEDAY                   #计算明天日期
    __WEEKDAY = __TODAY.strftime('%w')                #计算当天是一星期的星期几

    __MYSQL_DUMP_ARGS = {                             #用一个字典存储mysqldump 命令备份数据库的参数
        'MYISAM': ' -v -E -e -R --triggers -F  -n --opt --master-data=2 --hex-blob -B ',
        'INNODB': ' -v -E -e -R --triggers -F --single-transaction -n --opt --master-data=2 --hex-blob -B '
    }

    __DUMP_COMMAND = __MYSQL_BIN_DIR + '/mysqldump'   #mysqldump 命令的 路径 用于dump mysql数据
    __FLUSH_LOG_COMMAND = __MYSQL_BIN_DIR + '/mysqladmin'    #mysqladmin 命令的路径 ，用于执行 flush-logs 生成每天增量binlog

    __BACKUP_DIR = r'/backup/'                        # 指定备份文件存放的目录

    __PROJECTNAME = 'example'                         # 指定需要备份的数据库对应的项目名，将来会生成 projectname-YYYY-MM-DD.sql 等文件
    __DATABASE_LIST = []                              # 指定需要备份的数据库名，可以是多个，使用列表
    __HOST = 'localhost'
    __PORT = 3306
    __USERNAME = 'root'
    __PASSWORD = ''
    __LOGINARGS = ''                                  # 如果在localhost登陆，需要密码，可以设定登陆的参数，具体在下面有说明
    __LOGFILE = __BACKUP_DIR + '/backup.logs'

    def __init__(self, baseDir=__MYSQL_BASE_DIR, backDir=__BACKUP_DIR, engine='MYISAM', projectName=__PROJECTNAME,
                 dbList=__DATABASE_LIST, host=__HOST, port=__PORT, user=__USERNAME, passwd=__PASSWORD):

        """
            实例化对象时传入的参数，如不传入默认使用类的私有成员变量作为默认值
    :param baseDir:
    :param backDir:
    :param engine:
    :param projectName:
    :param dbList:
    :param host:
    :param port:
    :param user:
    :param passwd:
    """
        self.__MYSQL_BASE_DIR = baseDir
        self.__BACKUP_DIR = backDir
        self.__PROJECTNAME = projectName
        self.__DATABASE_LIST = dbList
        self.__HOST = host
        self.__PORT = port
        self.__USERNAME = user
        self.__PASSWORD = passwd
        self.__ENGINE = self.__MYSQL_DUMP_ARGS[engine]
        #下面定义了如需登陆时，参数 其实就是生成 这样的格式  “-hlocalhost -uroot --password=‘xxxx’”
        self.__LOGINARGS = " -h" + self.__HOST + " -P" + str(
            self.__PORT) + " -u" + self.__USERNAME + " --password='" + self.__PASSWORD + "'"
        self.checkDatabaseArgs()   #调用检查函数

    def __getconfig(self, cnf=__MYSQL_CONFIG_FILE, item=None):  # 解析mysql配置文件的小函数，简单封装了下，传入一个值作为my.cnf的key去查找对应的value

        __mycnf = ConfigParser.ConfigParser()
        __mycnf.read(cnf)
        try:
            return __mycnf.get("mysqld", item)
        except BaseException, e:
            sys.stderr.write(str(e))
            sys.exit(1)

    def __getBinlogPath(self): #  取每天需要增量备份的binlog日志的绝对路径，从mysql的binlog.index文件取倒数第二行

        __BINLOG_INDEX = self.__getconfig(item='log-bin') + '.index'

        if not os.path.isfile(__BINLOG_INDEX):
            sys.stderr.write('BINLOG INDEX FILE: [' + __BINLOG_INDEX + ' ] NOT FOUND! \n')
            sys.exit(1)
        else:
            try:
                __BINLOG_PATH = linecache.getline(__BINLOG_INDEX, len(open(__BINLOG_INDEX,'r').readlines()) - 1)
                linecache.clearcache()
            except BaseException, e:
                sys.stderr.write(str(e))
                sys.exit(1)
            return __BINLOG_PATH.strip()

    def flushDatabaseBinlog(self):  # 调用此函数，将会执行  mysqladmin flush-logs ,刷新binlog日志
        return os.popen(self.__FLUSH_LOG_COMMAND + self.__LOGINARGS + ' flush-logs')

    def dumpDatabaseSQL(self):  #|通过mysqladmin 对指定数据库进行全备
        if not os.path.isfile(self.__BACKUP_DIR + '/' + self.__PROJECTNAME + '/' + str(self.__YESTERDAY) + '-' + self.__PROJECTNAME + '.sql'):
            return os.popen(self.__DUMP_COMMAND + self.__LOGINARGS + self.__ENGINE + ' '.join(
                self.__DATABASE_LIST) + ' >> ' + self.__BACKUP_DIR + '/' + self.__PROJECTNAME + '/' +str(
                self.__YESTERDAY) + '-' + self.__PROJECTNAME + '.sql')
        else:
            sys.stderr.write('Backup File [' + str(self.__YESTERDAY) + '-' + self.__PROJECTNAME +'.sql]  already exists.\n')



    def dumpDatabaseBinlog(self):#通过copy2() 将需要备份的binlog日志复制到指定备份目录

        if not os.path.isfile(self.__BACKUP_DIR + '/' + self.__PROJECTNAME + '/' +str(self.__YESTERDAY) + '-' + os.path.split(self.__getBinlogPath())[1]):
            from shutil import copy2
            try:
                copy2(self.__getBinlogPath(), self.__BACKUP_DIR + '/' + self.__PROJECTNAME + '/' +str(self.__YESTERDAY) + '-' + os.path.split(self.__getBinlogPath())[1])
            except BaseException, e:
                sys.stderr.write(str(e))
        else:
            sys.stderr.write('Binlog File [' + str(self.__YESTERDAY) + '-' +os.path.split(self.__getBinlogPath())[1] + '] already exists\n' )


    def checkDatabaseArgs(self):  #对一些必要条件进行检查
        __rv = 0

        if not os.path.isdir(self.__MYSQL_BASE_DIR):  #检查指定的mysql安装目录是否存在
            sys.stderr.write('MYSQL BASE DIR: [ ' + self.__MYSQL_BASE_DIR + ' ] NOT FOUND\n')
            __rv += 1

        if not os.path.isdir(self.__BACKUP_DIR):   #检查指定的备份目录是否存在，如不存在自动创建
            sys.stderr.write('BACKUP DIR: [ ' + self.__BACKUP_DIR + '/' + self.__PROJECTNAME +  ' ] NOT FOUND ,AUTO CREATED\n')
            os.makedirs(self.__BACKUP_DIR + '/' + self.__PROJECTNAME)

        if not os.path.isfile(self.__MYSQL_CONFIG_FILE): #检查mysql配置文件是否存在
            sys.stderr.write('MYSQL CONFIG FILE: [' + self.__MYSQL_CONFIG_FILE + ' ] NOT FOUND\n')
            __rv += 1

        if not os.path.isfile(self.__DUMP_COMMAND):  #检查备份数据库时使用的mysqldump命令是否存在
            sys.stderr.write('MYSQL DUMP COMMAND: [' + self.__DUMP_COMMAND + ' ] NOT FOUND\n')
            __rv += 1

        if not os.path.isfile(self.__FLUSH_LOG_COMMAND): #检查刷新mysql binlog日志使用的mysqladmin命令是否存在
            sys.stderr.write('MYSQL FLUSH LOG COMMAND: [' + self.__DUMP_COMMAND + ' ] NOT FOUND\n')
            __rv += 1

        if not self.__DATABASE_LIST:  #检查需要备份的数据库列表是否存在
            sys.stderr.write('Database List is None \n')
            __rv += 1

        if __rv:   # 判断返回值，由于上述任何一步检查失败，都会导致 __rv 值 +1 ，只要最后__rv ！= 0就直接退出了。
            sys.exit(1)


def crontab():  # 使用字典，来进行相关参数传递，并实例化对象，调用相关方法进行操作

    zabbix = {
        'baseDir': '/usr/local/mysql/',
        'backDir': '/backup/',
        'projectName': 'Monitor',
        'dbList': ['zabbix'],
        'host': 'localhost',
        'port': 3306,
        'user': 'root',
        'passwd': 'xxxxxxx'
    }

    monitor = DatabaseArgs(**zabbix)
    monitor.dumpDatabaseSQL()
    monitor.dumpDatabaseBinlog()
    monitor.flushDatabaseBinlog()

if __name__ == '__main__':
    crontab()

my.cnf

[client]
port                            = 3306
socket                          = /mysql/var/db.socket

[mysqld]
socket                          = /mysql/var/db.socket
datadir                         = /mysql/db/
skip-external-locking           = 1
skip-innodb                     = 0
key_buffer_size                 = 256M
max_allowed_packet              = 10M
table_open_cache                = 2048
sort_buffer_size                = 4M
read_buffer_size                = 4M
read_rnd_buffer_size            = 8M
myisam_sort_buffer_size         = 64M
myisam_max_sort_file_size       = 1G
myisam_repair_threads           = 1
myisam_recover                  = DEFAULT
thread_cache_size               = 32
query_cache_size                = 32M
query_cache_min_res_unit        = 2k
bulk_insert_buffer_size         = 64M
tmp_table_size                  = 128M
thread_stack                    = 192K
skip-name-resolve               = 1
max_connections                 = 65500
default-storage-engine          = myisam
federated                       = 0
server-id                       = 1
slave-skip-errors               = all
#log                            = /var/log/sql_query.log
slow-query-log                  = 1
slow-query-log-file             = /mysql/log/sql_query_slow.log
long-query-time                 = 5
log-queries-not-using-indexes   = 1
log-slow-admin-statements       = 1
log-bin                         = /mysql/var/log/binlog/bin-log
log-error                       = /mysql/var/log/mysql.err
master-info-file                = /mysql/var/log/master.info
relay-log                       = /mysql/var/log/relay-bin/relay-bin
relay-log-index                 = /mysql/var/log/relay-bin/relay-bin.index
relay-log-info-file             = /mysql/var/log/relay-bin/relay-bin.info
binlog_cache_size               = 8M
binlog_format                   = MIXED
max_binlog_cache_size           = 20M
max_binlog_size                 = 1G
binlog-ignore-db                = mysql
binlog-ignore-db                = performance_schema
binlog-ignore-db                = information_schema
replicate-ignore-db             = mysql
replicate-ignore-db             = performance_schema
replicate-ignore-db             = information_schema

innodb_data_home_dir            = /mysql/ibdata/
innodb_data_file_path           = ibdata:156M:autoextend
innodb_log_group_home_dir       = /mysql/ibdata/
log-slave-updates               = 0
back_log                        = 512
transaction_isolation           = READ-COMMITTED
max_heap_table_size             = 246M
interactive_timeout             = 120
wait_timeout                    = 120
innodb_additional_mem_pool_size = 16M
innodb_buffer_pool_size         = 512M
innodb_file_io_threads          = 4
innodb_thread_concurrency       = 8
innodb_flush_log_at_trx_commit  = 2
innodb_log_buffer_size          = 16M
innodb_log_file_size            = 128M
innodb_log_files_in_group       = 3
innodb_max_dirty_pages_pct      = 90
innodb_lock_wait_timeout        = 120
innodb_file_per_table           = 1
innodb_open_file                = 327500
open_files_limit                = 327500

[mysqldump]
quick                           = 1
max_allowed_packet              = 50M

[mysql]
auto-rehash                     = 1
socket                          = /mysql/var/db.socket
safe-updates                    = 0

[myisamchk]
key_buffer_size                 = 256M
sort_buffer_size                = 256M
read_buffer                     = 2M
write_buffer                    = 2M

[mysqlhotcopy]
interactive-timeout             = 100

The final generated backup directory structure is like this

[root@zabbix backup]# find ./
./
./Monitor
./Monitor/2013-03-16-bin-log.000008
./Monitor/2013-03-14-bin-log.000006
./Monitor/2013-03-16-Monitor.sql
./Monitor/2013-03-15-Monitor.sql
./Monitor/2013-03-15-bin-log.000007
./Monitor/2013-03-14-Monitor.sql

~END~