Adding Docker to a Ruby gem
As a maintainer of a few Ruby gems, I have to decide what is accepted and what gets rejected into the gems. The other day someone submitted a pull request to add a Dockerfile to DatabaseCleaner
I thought it was a good idea, because the current version of DatabaseCleaner requires you to have Postgres, MySQL, Redis, and Mongo up and running before you run rake.
Here are the steps:
-
Download the Docker Toolbox , a 176+ MB package.
-
Install the package, which will expand to 400+ MB in your filesystem.
-
In the terminal:
docker-machine start default -
Then within your project:
docker-compose up(before this I had to runeval "$(docker-machine env default)"because of this issue ). Get ready to wait for a few minutes while it sets up your virtual machine. -
Finally:
docker-compose run --rm gem
Supposedly these steps should start the required services and run the build. I was expecting to watch it pass, but this is what I saw:
Installing mongo_ext 0.19.3 with native extensions
Gem::Ext::BuildError: ERROR: Failed to build gem native extension.
/usr/local/rvm/rubies/ruby-2.2.2/bin/ruby -r ./siteconf20151224-6-fhvc98.rb extconf.rb
checking for asprintf()... *** extconf.rb failed ***
Could not create Makefile due to some reason, probably lack of necessary
libraries and/or headers. Check the mkmf.log file for more details. You may
need configuration options.
Provided configuration options:
--with-opt-dir
--without-opt-dir
--with-opt-include
--without-opt-include=${opt-dir}/include
--with-opt-lib
--without-opt-lib=${opt-dir}/lib
--with-make-prog
--without-make-prog
--srcdir=.
--curdir
--ruby=/usr/local/rvm/rubies/ruby-2.2.2/bin/$(RUBY_BASE_NAME)
If I were to add this contribution, I’d make sure that the CONTRIBUTE.markdown lists Docker as an option to run the specs, not as the default.