Мой docker file
FROM php:7.2.2-fpm
RUN apt-get update && \
apt-get install -y --no-install-recommends git zip
RUN apt -yqq update
RUN apt -yqq install nginx iputils-ping
RUN curl -sS https://getcomposer.org/installer | php -- --install-dir=/usr/local/bin --filename=composer
WORKDIR /var/www/html
RUN composer install
EXPOSE 9000
CMD ["php-fpm"]
Выводится ошибка
Do not run Composer as root/super user! See https://getcomposer.org/root for details
Composer could not find a composer.json file in /var/www/html
To initialize a project, please create a composer.json file as described in the https://getcomposer.org/ "Getting Started" section
Захожу по этому пути /var/www/html composer.json там есть . в чем моя ошибка?