It seems to me that the default Rails 6 install with webpacker presents a problem.
Within my Dockerfile, I have the line:
COPY . /usr/src/app/
RUN bundle exec rake webpacker:install
Which builds fine by itself, but it fails when adding the volume to docker-compose.yml
volumes:
- .:/usr/src/app
It seems to be because the config/webpacker.yml gets overwritten when docker-compose performs the mount.