FROM ruby:2.6.3-alpine AS base

ARG BUILD_PACKAGES="build-base git"
ARG DEV_PACKAGES="postgresql-dev nodejs yarn"
ARG RUBY_PACKAGES="tzdata"

# Add git to clone Rspec repositories and build-base to compile nokogiri gem
# Additionally, we need to set timezone information
RUN apk add --update --no-cache $BUILD_PACKAGES $DEV_PACKAGES $RUBY_PACKAGES

# Make an app directory, just like Heroku.
RUN mkdir /app
WORKDIR /app

################################################################################
FROM base AS builder

# Copying the Gemfile separately allows the image to be cached.
# These steps are not rerun unless the Gemfile or Gemfile.lock is changed.
COPY Gemfile Gemfile.lock /app/
RUN bundle install --jobs 4 --retry 5 --without development test

# Again, copy seperately so we can cache this step.
COPY package.json yarn.lock /app/
RUN yarn install

# Copy our app over now
COPY . /app

# And compile our assets, removing unneeded node_modules directory afterwards
RUN rails assets:precompile && \
      rm -rf node_modules tmp/cache app/assets vendor/assets spec

# Copy the docker configurations over
COPY config/database.yml.docker config/database.yml

################################################################################
# We want a tiny image, so don't start from base
FROM ruby:2.6.3-alpine AS prod

ENV RAILS_ENV=production

RUN apk add --update --no-cache $RUBY_PACKAGES

# Grab everything from the builder
COPY --from=builder /usr/local/bundle/ /usr/local/bundle/
COPY --from=builder /app/ /app/

# Run the server
EXPOSE 3000
CMD ["rails", "server", "-b", "0.0.0.0"]