MySQL数据库备份脚本

[root@myhost ~]# cat  /home/script/mysqlbackup.sh
#!/bin/sh 
source /etc/profile
#define variables
#the login information of your mysql db.
login_user=""
login_passwd=""       #数据库密码最好不要含有$符号，因为避免被当成变量，这是个大坑，被坑惨了
db_host=""   
db_port=""
#the real databases which you want to backup.
db_array=("db_name0" "db_name1" "db_name2")
#the dir for saving your backup file.
backup_dir="/home/backup/mysql_bak/$db_host-backup"
if [ ! -d  $backup_dir ];then
	mkdir -p $backup_dir
fi 
#date format for the backup file (yyyy-mm-dd) 
time=`date +"%Y-%m-%d"`
#the mysql,mysqldump and other bin's path
MYSQL_COMMDAND=""   			#根据自己的数据库安装路径决定
MYSQLDUMP_COMMAND=""			#根据自己的数据库安装路径决定
MKDIR_COMMAND="/bin/mkdir"
RM_COMMAND="/bin/rm"
MV_COMMAND="/bin/mv"
GZIP_COMMAND="/bin/gzip"

# check the dir for saving backup file is writeable or not.
if [ ! -w  $backup_dir ];then

	echo "Error: $backup_dir is un-writeable." && exit 0 

fi

#check if the dir for saving the backup file exists or not.
if [ ! -d  ${backup_dir}/backup.0 ];then

	$MKDIR_COMMAND  -p "$backup_dir/backup.0"

fi

#starting to backup.

for db_name in ${db_array[*]}
do
	$MYSQLDUMP_COMMAND -P$db_port -u$login_user -h$db_host  --set-gtid-purged=off -p$login_passwd -B  $db_name | $GZIP_COMMAND -9 > "$backup_dir/backup.0/$time.$db_name.gz" 
done

# delete the oldest backup 
if [ -d "$backup_dir/backup.7" ];then

	$RM_COMMAND -rf "$backup_dir/backup.7" 

fi


# rotate backup directory 

#for int in 6 5 4 3 2 1 0 
for int in {6..0}
do 
	if [ -d "$backup_dir"/backup."$int" ];then
		next_int=`expr  $int  + 1` 
		$MV_COMMAND "$backup_dir"/backup."$int" "$backup_dir"/backup."$next_int" 
	fi
done 
	
exit 0; 

[root@myhost ~]# cat /etc/crontab
SHELL=/bin/bash
PATH=/sbin:/bin:/usr/sbin:/usr/bin
MAILTO=root
HOME=/

# For details see man 4 crontabs

# Example of job definition:
# .---------------- minute (0 - 59)
# |  .------------- hour (0 - 23)
# |  |  .---------- day of month (1 - 31)
# |  |  |  .------- month (1 - 12) OR jan,feb,mar,apr ...
# |  |  |  |  .---- day of week (0 - 6) (Sunday=0 or 7) OR sun,mon,tue,wed,thu,fri,sat
# |  |  |  |  |
# *  *  *  *  * user-name command to be executed
30 3  *  *  * root /home/script/mysqlbackup.sh

[root@myhost ~]#  cd $backup_dir  && ll
##假设备份文件名为：2019-09-29.dbname.gz
[root@myhost ~]#  gzip -d 2019-09-29.dbname.gz && ll    #解压备份文件之后文件名： 2019-09-29.dbname
[root@myhost ~]#  cat  2019-09-29.dbname > 2019-09-29_dbname.sql 或者 mv  2019-09-29.dbname  2019-09-29_dbname.sql 
[root@myhost ~]# mysql -uroot -proot123456 -B  dbname <   2019-09-29_dbname.sql   #恢复数据库