# Docker for Rails Developers(p60): webpacker install fails in docker-compose if volume used

**URL:** <https://forum.devtalk.com/t/docker-for-rails-developers-p60-webpacker-install-fails-in-docker-compose-if-volume-used/2337>\
**Category:** PragProg Customers\
**Tags:** question, book-docker-for-rails-developers\
**Created:** [19 September 2020 04:49 UTC](https://forum.devtalk.com/t/docker-for-rails-developers-p60-webpacker-install-fails-in-docker-compose-if-volume-used/2337 "2020-09-19T04:49:58Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![Big-Gray-Al](https://forum.devtalk.com/letter_avatar_proxy/v4/letter/b/2acd7d/32.png) [@Big-Gray-Al](https://forum.devtalk.com/u/Big-Gray-Al)\
**Post date:** [19 September 2020 04:49 UTC](https://forum.devtalk.com/t/docker-for-rails-developers-p60-webpacker-install-fails-in-docker-compose-if-volume-used/2337/1 "2020-09-19T04:49:58Z")

</div>

It seems to me that the default Rails 6 install with webpacker presents a problem.

Within my Dockerfile, I have the line:

```auto
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

```auto
volumes:
- .:/usr/src/app

```

It seems to be because the config/webpacker.yml gets overwritten when docker-compose performs the mount.