docker-entrypoint.sh

#!/bin/bash
set -e

: "${MYSQL_ROOT_PASSWORD:=O5Nz88BTPc6krzQ2gQuXJMOEroVKiY9po1LZSy1UQBk}"
: "${MYSQL_DATABASE:-wordpress}"
: "${MYSQL_USER:-wpuser}"
: "${MYSQL_PASSWORD:-wpuser}"

if [ ! -f /docker-entrypoint-initdb.d/flagfile ]; then
    # If the command executed is 'mariadbd'
    if [ "$1" = 'mariadbd' ]; then
        # Check if we are running as root
        if [ "$(id -u)" = '0' ]; then
            # Start the MySQL server in the background as root
            mysqld_safe &

            # Wait for the server to start up
            sleep 5s

            # Set the root password only if it is not already set
            if mysqladmin -u root password >/dev/null 2>&1; then
                mysql -e "ALTER USER 'root'@'localhost' IDENTIFIED BY '$MYSQL_ROOT_PASSWORD';"
            else
                echo "Root user in MySQL has a password."
            fi

            # Stop the server
            mysqladmin -u root -p"$MYSQL_ROOT_PASSWORD" shutdown

            # If we are, use gosu to step down from root
            exec gosu mysql "$BASH_SOURCE" "$@"
        fi

        # Start the MySQL server in the background
        "$@" --skip-networking --socket=/tmp/mysql.sock &

        # Wait for the server to start up
        mysql=( mysql --protocol=socket -uroot -p"$MYSQL_ROOT_PASSWORD" -hlocalhost --socket=/tmp/mysql.sock )
        for i in {30..0}; do
            if echo 'SELECT 1' | "${mysql[@]}" &> /dev/null; then
                break
            fi
            sleep 1
        done
        if [ "$i" = 0 ]; then
            echo >&2 'MySQL init process failed.'
            exit 1
        fi

        # Create a new database only if it does not already exist
        if [ -n "$MYSQL_DATABASE" ]; then
            echo "CREATE DATABASE IF NOT EXISTS \`$MYSQL_DATABASE\` ;" | "${mysql[@]}"
        fi

        # Create a new user only if it does not already exist
        if [ -n "$MYSQL_USER" -a -n "$MYSQL_PASSWORD" ]; then
            echo "CREATE USER IF NOT EXISTS '$MYSQL_USER'@'%' IDENTIFIED BY '$MYSQL_PASSWORD' ;" | "${mysql[@]}"
            echo "GRANT ALL ON *.* TO '$MYSQL_USER'@'%' ;" | "${mysql[@]}"
            echo 'FLUSH PRIVILEGES ;' | "${mysql[@]}"
        fi

        # Stop the server
        if ! mysqladmin --protocol=socket -uroot -p"$MYSQL_ROOT_PASSWORD" -hlocalhost --socket=/tmp/mysql.sock shutdown; then
            echo >&2 'MySQL init process failed.'
            exit 1
        fi

        echo
        echo 'MySQL init process done. Ready for start up.'
        echo
    fi
else
    echo 'Database initialization is already completed'
fi

if [ ! -f /docker-entrypoint-initdb.d/flagfile ]; then
    touch /docker-entrypoint-initdb.d/flagfile
    # Run the command (this will start the MySQL server)
    exec "$@"
else
    # Run the command (this will start the MySQL server)
    exec gosu mysql "$@"
fi