Running composer install within a Dockerfile

I'm attempting to Dockerize a Laravel application. The app is already created and in git, but my vendor folder is.gitignored. I've added a Dockerfile with the following contents:

FROM php:7.1-fpm-alpine

RUN apk update && apk add curl && \
  curl -sS https://getcomposer.org/installer | php \
  && chmod +x composer.phar && mv composer.phar /usr/local/bin/composer

RUN apk --no-cache add --virtual .build-deps $PHPIZE_DEPS \
  && apk --no-cache add --virtual .ext-deps libmcrypt-dev freetype-dev \
  libjpeg-turbo-dev libpng-dev libxml2-dev msmtp bash openssl-dev pkgconfig \
  && docker-php-source extract \
  && docker-php-ext-configure gd --with-freetype-dir=/usr/include/ \
                                   --with-png-dir=/usr/include/ \
                                   --with-jpeg-dir=/usr/include/ \
  && docker-php-ext-install gd mcrypt mysqli pdo pdo_mysql zip opcache \
  && pecl install mongodb redis xdebug \
  && docker-php-ext-enable mongodb \
  && docker-php-ext-enable redis \
  && docker-php-ext-enable xdebug \
  && docker-php-source delete \
  && apk del .build-deps

WORKDIR /var/www/html

COPY composer.json composer.lock ./
RUN composer install --no-scripts --no-autoloader

COPY . .
RUN chmod +x artisan

RUN composer dump-autoload --optimize && composer run-script post-install-cmd

CMD php artisan serve --host 0.0.0.0 --port 5001

This appears to function well when I'm building. In the output, I see the dependencies being downloaded and the autoload file being generated. However, once the build is finished, the vendor folder is missing. I'm presuming everything was done in a temporary container that was subsequently removed? So when I run docker-compose up, I get: Fatal error: require(): Failed opening required '/var/www/html/bootstrap/../vendor/autoload.php'

I looked at some other threads but wasn't able to find a suitable answer.

No answer to this question. Be the first to respond.