bundle install --deployment got "Could not locate Gemfile"

[agate]

Hi,

I am trying to build a docker image. And my Dockerfile is like this.

RUN mkdir -p /tmp/bundle
ADD Gemfile.lock /tmp/bundle/Gemfile.lock
RUN cd /tmp/bundle && bundle install --deployment --path=/bundle

I only add Gemfile.lock (without Gemfile). It's because there are some complicated requirements in the original Gemfile. So it can not work alone in docker.

So I have some questions:

• Why under deployment mode I got the error: "Could not locate Gemfile"
• Does --deployment mode still need Gemfile ? If so, is that possible to generate a Gemfile based on Gemfile.lock?

[segiddins]

You still need to add your gemfile, bundler requires both the gemfile and the lockfile to work.

[agate]

@segiddins is there a way to reverse Gemfile.lock to Gemfile?

[agate]

Can I just use the gems under DEPENDENCIES in Gemfile.lock?

[segiddins]

@agate there is not, as information in the gemfile such as groups, platforms, install conditionals are not stored in the lockfile

[agate]

Aha! That make sense. Thanks for the explanation. I don't have those special info in my original Gemfile. I can simply read the DEPENDENCIES in Gemfile.lock and revert it. So I wrote a gem for this.

• https://github.com/agate/gemfile_lock_to_gemfile
• https://rubygems.org/gems/gemfile_lock_to_gemfile

[segiddins]

Cool!