#!/bin/bash

# Created on: July 26, 2018
# Created by: Andrew Abraham
# Purpose:
#    This script will restore a local mysql database to a Azure Mysql Server.
#    It is set to drop the target DB prior to restoring this dump.
#    I created to restore a copy of the a local db to azure every night using a cron.


## Vars ##
DB=''
MY_LOC_USER=''
MY_LOC_PASS=''
MY_AZ_USER=''
MY_AZ_PASS=''
AZ_HOST=''
DUMP_FILE='/mysql/dump.sql'
LOG_FILE='/var/log/mysql_restore_azure.log'


## Functions ##
dump_db (){
	echo "$(date '+%Y-%m-%d %H:%M:%S') -- Starting ${DB} dump to ${DUMP_FILE} ..." | tee -a ${LOG_FILE}
	mysqldump -u $1  -p"$2" --databases --add-drop-database --events --triggers --routines $3 > $4 && \
	echo "$(date '+%Y-%m-%d %H:%M:%S') -- Completed dumped to ${DUMP_FILE} successfully!" | tee -a ${LOG_FILE}
}

prep_dump (){
	DUMP="$1"
	echo "$(date '+%Y-%m-%d %H:%M:%S') -- Refactoring MyISAM to InnoDB & removing Definer references in dump file..." | tee -a ${LOG_FILE}
	sed -i 's/MyISAM/InnoDB/g' ${DUMP} && \
	sed -i 's/DEFINER=[^*]*\*/\*/g' ${DUMP} && \
	echo "$(date '+%Y-%m-%d %H:%M:%S') -- Completed dump file preperation for restore to Azure!" | tee -a ${LOG_FILE}
}

restore_db (){
	echo "$(date '+%Y-%m-%d %H:%M:%S') -- Starting DB restore to Azure..." | tee -a ${LOG_FILE}
	mysql -u $1 -p"$2" -h "$3" < "$4" && \
	echo "$(date '+%Y-%m-%d %H:%M:%S') -- ${DB} successfully restored to ${AZ_HOST}" | tee -a ${LOG_FILE}
}


## Main ##
dump_db "${MY_LOC_USER}" "${MY_LOC_PASS}" "${DB}" "${DUMP_FILE}" && \
prep_dump "${DUMP_FILE}" && \
restore_db "${MY_AZ_USER}" "${MY_AZ_PASS}" "${AZ_HOST}" "${DUMP_FILE}"