Dockerfile

FROM php:7.4-fpm

RUN apt-get update && apt-get install -y git zip unzip

COPY --from=composer:2 /usr/bin/composer /usr/bin/composer

WORKDIR /app

# to cache composer dependencies, we do not compile container on first run
COPY composer.json ./
RUN --mount=type=ssh (mkdir -p -m 0600 ~/.ssh && ssh-keyscan -t rsa github.com >> ~/.ssh/known_hosts) \
   && composer install -o --prefer-dist --no-interaction --no-scripts