mysql-check.sh

#!/bin/bash -eux

source /etc/environment

echo "=> Trying to connect to MySQL/MariaDB using:"
echo "========================================================================"
echo "      Database Host Address:  $DB_HOST"
echo "      Database Port number:   $DB_PORT"
echo "      Database Username:      $DB_USER"
echo "      Database Password:      $DB_PASS"
echo "========================================================================"

for ((i=0;i<10;i++))
do
    DB_CONNECTABLE=$(mysql -u$DB_USER -p$DB_PASS -h$DB_HOST -P$DB_PORT -e 'status' >/dev/null 2>&1; echo "$?")
    if [[ DB_CONNECTABLE -eq 0 ]]; then
        exit 0
    fi
    sleep 5
done

exit 1