Why won't composer install run?

Question

Composer

My dockerfile

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"]

An error is displayed

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

I go to this path /var/www/html composer.json is there. what's my mistake?

Answer 1

There is a solution?))