Remove gem install bundler from Docker-based Ruby environments
Problem to solve
Remove gem install bundler from Docker-based Ruby environments to save time.
cf. #55837 (closed), #55740 (closed)
Target audience
GitLab's Ruby .gitlab-ci.yml
template users will save time to check if the bundler package is installed.
Further details
In the Docker official Ruby image, bundler has been already bundled at least since Ruby 2.1.
cf. https://github.com/docker-library/ruby/commit/1f9102c4e5c9fb9842e09c3c50f6402ed583456a
The version of bundler
packages in the Docker official images follows:
$ for v in 2.{1,2,3,4,5,6}; do docker run --rm -it ruby:$v sh -c 'ruby -v; bundle --version'; done
ruby 2.1.10p492 (2016-04-01 revision 54464) [x86_64-linux]
Bundler version 1.15.1
ruby 2.2.10p489 (2018-03-28 revision 63023) [x86_64-linux]
Bundler version 1.16.1
ruby 2.3.8p459 (2018-10-18 revision 65136) [x86_64-linux]
Bundler version 1.17.3
ruby 2.4.5p335 (2018-10-18 revision 65137) [x86_64-linux]
Bundler version 1.17.3
ruby 2.5.3p105 (2018-10-18 revision 65156) [x86_64-linux]
Bundler version 1.17.3
ruby 2.6.0p0 (2018-12-25 revision 66547) [x86_64-linux]
Bundler version 1.17.3
Proposal
Remove from the gitlab-ci yaml template for Ruby and the related docs.
What does success look like, and how can we measure that?
We might measure how many seconds a user can save in a single pipeline.