running composer install in Dockerfile - php

Question

I am trying to dockerize a PHP laravel app. I am using a PHP and a composer image to achieve this. However, when I run composer install, I get all my packages installed but then run into this error:
/app/vendor does not exist and could not be created.
I want composer to create the /vendor directory! Could this be a permission issue?
Here is my Dockerfile:
FROM php:7.4.3-cli
# Install system dependencies
RUN apt-get update && apt-get install -y \
git \
curl \
libpng-dev \
libonig-dev \
libxml2-dev \
zip \
unzip
# Clear cache
RUN apt-get clean && rm -rf /var/lib/apt/lists/*
# Install PHP extensions
RUN docker-php-ext-install pdo_mysql mbstring exif pcntl bcmath gd
COPY --from=composer:2.4.4 /usr/bin/composer /usr/local/bin/composer
# Set working directory
WORKDIR /app
COPY . .
# Add a new user "john" with user id 8877
RUN useradd -u 8877 john
# Change to non-root privilege
USER john
RUN composer install
I created a user with an arbitrary ID since it's a bad practice to run composer install as root security-wise.

Answer 1

I was able to solve the problem by making some changes to my Dockerfile:
FROM php:7.4.3-cli
# Install system dependencies
RUN apt-get update && apt-get install -y \
git \
curl \
libpng-dev \
libonig-dev \
libxml2-dev \
zip \
unzip
# Clear cache
RUN apt-get clean && rm -rf /var/lib/apt/lists/*
# Install PHP extensions
RUN docker-php-ext-install pdo_mysql mbstring exif pcntl bcmath gd
COPY --from=composer:2.4.4 /usr/bin/composer /usr/local/bin/composer
# Add a new user "john" with user id 8877
RUN useradd -u 8877 john
# Set working directory
WORKDIR /app
COPY . .
RUN chmod -R 775 /app
RUN chown -R john:john /app
# Change to non-root privilege
USER john
RUN composer install --no-scripts --no-plugins