Run opus in docker-container

docker-entrypoint.sh

#!/bin/sh

cd /var/www/html

if [ -f "./.env" ]; then
    source .env
fi

composer install --no-plugins --no-scripts &&
php artisan migrate

if [ -z "$FIRST_RUN" ]; then
    php artisan key:generate
    php artisan db:seed
fi

chown www-data:www-data . -Rf

if [ "${1#-}" != "$1" ]; then
    set -- apache2-foreground "$@"
fi

exec "$@"

Dockerfile

FROM php:7.1-apache

RUN export CFLAGS="$PHP_CFLAGS" CPPFLAGS="$PHP_CPPFLAGS" LDFLAGS="$PHP_LDFLAGS" \
    && apt-get update > /dev/null \
    && apt-get install -yyq \
    git \
    curl \
    unzip \
    > /dev/null \
    && docker-php-ext-install \
    pdo_mysql \
    iconv \
    pdo \
    > /dev/null \
    && docker-php-ext-enable \
    pdo_mysql \
    iconv \
    pdo \
    > /dev/null \
    && apt-get clean \
    && rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*

RUN a2enmod rewrite

RUN sed -i /etc/apache2/sites-enabled/000-default.conf -e "s#www/html#www/html/public#"

RUN curl -Lo /usr/local/bin/composer https://getcomposer.org/composer.phar \
    && chmod +x /usr/local/bin/composer

COPY . /var/www/html/

RUN chmod +x /var/www/html/docker-entrypoint.sh
ENTRYPOINT ["/var/www/html/docker-entrypoint.sh"]

Men, there are a way for externalize de database to other docker container or volumen?