How to not show wordpress installation page at first time?

I'm building a website using docker-compose and 3 docker containers (mariadb/nginx/wordpress) and I want to install wordpress in a script, so my wordpress Dockerfile looks like this

from    debian:buster

run     apt-get update -y;\
        apt-get install -y curl mariadb-client\
            php php7.3 php7.3-fpm php7.3-mysql php-common php7.3-cli\
            php7.3-common php7.3-json php7.3-opcache php7.3-readline\
            php-curl php-gd php-intl php-mbstring php-soap php-xml php-xmlrpc\
            php-zip

run     mkdir -p /var/www/html;\
        cd /var/www/html

add     conf/php-fpm.conf /etc/php/7.3/fpm/pool.d/www.conf
add     conf/init_wp.sh /tmp

run     mkdir -p /var/run /run/php
run     curl -O https://raw.githubusercontent.com/wp-cli/builds/gh-pages/phar/wp-cli.phar
run     chmod +x wp-cli.phar
run     mv wp-cli.phar /usr/local/bin/wp

workdir /var/www/html
run     wp core download --allow-root
run     chown -R www-data:www-data /var/www/html

cmd     [ "sh", "/tmp/init_wp.sh" ]

and my entrypoint script looks like this

FILE=/var/www/html/.exist

if  [ ! -f "$FILE" ]
then
    echo "Setting up wordpress"
    rm -rf /var/www/html/wp-config.php
    wp config create --dbname=$DB_NAME --dbuser=$WP_USER --dbpass=$WP_PASSWORD --dbhost="mariadb" --path="/var/www/html/" --allow-root --skip-check
    wp core install --url="localhost" --title="inception" --admin_user=$ADMIN_USER --admin_password=$ADMIN_PASSWORD --admin_email=$ADMIN_EMAIL --path="/var/www/html/" --allow-root
    wp user create testuser testuser@student.42.fr --role=author --user_pass="abc123" --allow-root
    touch /var/www/html/.exist
fi

echo "Wordpress setup done"
exec php-fpm7.3 -F -R

but when I load the website for the first time I still get redirected to the wordpress installation page, shouldn't wp config create and wp core install do this for me ? What did I do wrong? mariadb works fine after the wordpress installation so the problem doesn't seem to come from here, so am I missing an element in the install script ?