mariadb_backup

#!/bin/bash

################################################################################
# Shell script to backup MariaDB databases.
################################################################################
#
# Este script puede programarse en el crontab con las siguientes opciones 
# (ojo a las rutas, que tendrán que adecuarse convenientemente):
# 
# 0 1 * * * /<ruta>/mariadb-backup /<ruta>/mariadb-backup.conf > /<ruta>/mariadb-backup.log 2>&1
#
################################################################################

# GNU/Linux bin paths
CHOWN="$(which chown)"
CHMOD="$(which chmod)"
DATE="$(which date)"
EXPR="$(which expr)"
FIND="$(which find)"
GZIP="$(which gzip)"
ID="$(which id)"
MKDIR="$(which mkdir)"
MV="$(which mv)"
MYSQLDUMP="$(which mysqldump)"

################################################################################
# HELPER FUNCTIONS
################################################################################
##
# Function that shows an error message and abort backup process.
#   $1 error description.
##
function showErrorAndExit()
{
  NOW=$(date +"%Y/%m/%d-%T")
  echo  $NOW "[ ERROR ] $1. Aborting." 1>&2
  exit 1
}

##
# Function that perform the backup process depending upon period given.
#   $1 period ( monthly | weekly | daily ) 
##
function doBackups()
{
  PERIOD=$1
  
  if [ $PERIOD == "daily" ];
  then
    SCHEMA_ONLY_DB_LIST=$D_SCHEMA_ONLY_DB_LIST
    FULL_BACKUP_DB_LIST=$D_FULL_BACKUP_DB_LIST
  elif [ $PERIOD == "weekly" ];
  then
    SCHEMA_ONLY_DB_LIST=$W_SCHEMA_ONLY_DB_LIST
    FULL_BACKUP_DB_LIST=$W_FULL_BACKUP_DB_LIST
  else
    SCHEMA_ONLY_DB_LIST=$M_SCHEMA_ONLY_DB_LIST
    FULL_BACKUP_DB_LIST=$M_FULL_BACKUP_DB_LIST
  fi
  
  echo -e "\n--------------------------------------------"  
  FINAL_BACKUP_DIR=$BACKUP_DIR"`$DATE +\%Y\%m\%d`-$PERIOD/"

  echo "Making backup directory in $FINAL_BACKUP_DIR"
  if ! $MKDIR -p $FINAL_BACKUP_DIR;
  then
    showErrorAndExit "Cannot create backup directory in $FINAL_BACKUP_DIR"
  fi;

  #### Schema-only backups ####
  echo -e "\nSchema-only backups ($PERIOD)"
  echo -e "--------------------------------------------"

  if [[ $SCHEMA_ONLY_DB_LIST ]];
  then
    echo -e "The following databases were matched for $PERIOD schema-only backup:\n${SCHEMA_ONLY_DB_LIST}\n"
  
    for DATABASE in $SCHEMA_ONLY_DB_LIST
    do
      echo "Performing schema-only backup of $DATABASE..."
    
      if ! $MYSQLDUMP --no-data -h $HOSTNAME -u $USERNAME -p$PASSWORD $DATABASE | $GZIP -9 > $FINAL_BACKUP_DIR"$DATABASE"_SCHEMA.sql.gz.in_progress;
      then
	showErrorAndExit "Failed to backup database schema of $DATABASE database"
      else
	$MV $FINAL_BACKUP_DIR"$DATABASE"_SCHEMA.sql.gz.in_progress $FINAL_BACKUP_DIR"$DATABASE"_SCHEMA.sql.gz
	echo "  done!"
      fi
    done
    
    echo -e "\nAll $PERIOD schema-only backups complete!"
  else
    echo -e "There are no databases matched for $PERIOD schema-only backup.\n"
  fi
  
  #### Full backups ####
  echo -e "\nFull backups ($PERIOD)"
  echo -e "--------------------------------------------"

  if [[ $FULL_BACKUP_DB_LIST ]];
  then
    echo -e "The following databases were matched for $PERIOD full backup:\n${FULL_BACKUP_DB_LIST}\n"
    
    for DATABASE in $FULL_BACKUP_DB_LIST
    do
      echo "Performing full backup of $DATABASE..."
    
      if ! $MYSQLDUMP -h $HOSTNAME -u $USERNAME -p$PASSWORD $DATABASE | $GZIP -9 > $FINAL_BACKUP_DIR"$DATABASE".sql.gz.in_progress;
      then
	showErrorAndExit "Failed to produce backup of $DATABASE database"
      else
	$MV $FINAL_BACKUP_DIR"$DATABASE".sql.gz.in_progress $FINAL_BACKUP_DIR"$DATABASE".sql.gz
	echo "  done!"
      fi
    done

    echo -e "\nAll $PERIOD database backups complete!"
  else
    echo -e "There are no databases matched for $PERIOD full backup.\n"
  fi
}


################################################################################
# MAIN
################################################################################
#### Load config settings ####
CONFIG_FILE_PATH=$1

if [ ! -r ${CONFIG_FILE_PATH} ];
then
  showErrorAndExit "Could not load config file from ${CONFIG_FILE_PATH}"
fi

#source "${CONFIG_FILE_PATH}"
. "${CONFIG_FILE_PATH}"

#### Pre-backup checks ####
# Make sure we're running as the required backup user
if [ $BACKUP_USER != "" -a "$($ID -un)" != "$BACKUP_USER" ];
then
  showErrorAndExit "This script must be run as $BACKUP_USER."
fi

#### Initialise defaults ####
if [ ! $HOSTNAME ];
then
  HOSTNAME="localhost"
fi;

if [ ! $USERNAME ];
then
  USERNAME="root"
fi;

#### Prepare backup directory ####
# Create main directory where backups will be stored, if needed
[ ! -d $BACKUP_DIR ] && $MKDIR -p $BACKUP_DIR || :

# Only root can access it!
$CHOWN 0.0 -R $BACKUP_DIR
$CHMOD 0600 $BACKUP_DIR

# Rock 'n Roll!!
#### Monthly backups ####
DAY_OF_MONTH=`$DATE +%d`
if [ $DAY_OF_MONTH -eq 1 ];
then
  # Delete all expired monthly directories
  $FIND $BACKUP_DIR -maxdepth 1 -name "*-monthly" -exec rm -rf '{}' ';'
  
  doBackups "monthly"
  
  # That's all folks!
  exit 0
fi

#### Weekly backups ####
DAY_OF_WEEK=`$DATE +%u` #1-7 (Monday-Sunday)
EXPIRED_DAYS=`$EXPR $((($WEEKS_TO_KEEP * 7) + 1))`
if [ $DAY_OF_WEEK = $DAY_OF_WEEK_TO_KEEP ];
then
  # Delete all expired weekly directories
  $FIND $BACKUP_DIR -maxdepth 1 -mtime +$EXPIRED_DAYS -name "*-weekly" -exec rm -rf '{}' ';'
  
  doBackups "weekly"
  
  # That's all folks!
  exit 0
fi

#### Daily backups ####
# Delete all expired daily directories
$FIND $BACKUP_DIR -maxdepth 1 -mtime +$DAYS_TO_KEEP -name "*-daily" -exec rm -rf '{}' ';'

doBackups "daily"

# That's all folks!
exit 0