testrunner-base-ruby

A basic Ruby + Rspec testrunner docker image that holds common infrastructure I keep using in various projects.

Note this is a heavily opinionated docker image, and I built it primarily for my personal use. Contributions are welcome but please keep in mind I'm not trying create a flexible, shareable tool here. :)

Test

To run your specs in parallel:

docker run --rm -it mycargus/testrunner-base-ruby bundle exec rspec-queue spec

To run the tests in sequence:

docker run --rm -it mycargus/testrunner-base-ruby bundle exec rspec spec

wait-for

Often I need to wait for dependent Docker containers to accept incoming connections on a specified port, i.e. the containers have finished "spinning up," before I can execute the tests. A common example is Postgres. To address this need I've created the wait-for utility.

For example, let's say you need to wait for a Postgres and Web container before running your tests:

set -e

docker run --rm mycargus/testrunner-base-ruby wait-for \
  postgres:5432 \
  web:8080

docker run --rm mycargus/testrunner-base-ruby bundle exec rspec

wait-for attempts to connect to postgres:5432 and web:8080 every 1 second until either both services are ready or the utility times out (default 30 seconds). In the above script, if Postgres and Web aren't both ready after 30 seconds or less then the RSpec tests won't run and the script will exit 1.

See bin/wait-for for details and options.

Develop

testrunner-base-ruby comes with a few prepackaged tools.

rubocop

We lint our Ruby with Rubocop. If you want to quickly auto-correct any violations then we have a handy script for that. You can use it like so:

docker run --rm mycargus/testrunner-base-ruby rubocop

See bin/rubocop for details.

Debug

While writing tests you may need to view the HTTP requests the tests send to other services. We're using the airborne gem and it uses the rest-client gem under the hood to send HTTP requests.

The easiest way to view the rest-client HTTP logs is to send them to STDOUT:

docker run --rm mycargus/testrunner-base-ruby \
  -e RESTCLIENT_LOG=stdout \
  bundle exec rspec

Run that ^ and you'll see plenty of info for each HTTP request and response.

The byebug gem

We autoload this gem. Just insert a byebug statement into your code and you're good to go.

The pry gem

We autoload this gem. Just insert a binding.pry statement into your code and you're good to go.

Pry is a powerful runtime developer console and IRB alternative for Ruby. We added a few useful Pry plugins to this project. Check out our .pryrc config file to learn a couple of tricks. Click the links below for more info.

pry pry-byebug pry-doc pry-state

Add a Ruby Gem

To add a Ruby gem, first build the image without your proposed changes:

docker build . -t mycargus/testrunner-base-ruby:latest

Then modify the Gemfile. Now you can generate the new Gemfile.lock:

docker run --rm -v "$PWD:/usr/src/app" mycargus/testrunner-base-ruby:latest \
  bundle install

Finally, to use your changes you must re-build the Docker image:

docker build . -t mycargus/testrunner-base-ruby:latest

This may seem like the hard way to add a dependency, especially compared to simply running bundle install in your terminal outside of Docker. The reason we recommend this approach is to make sure we're preserving the same Ruby version and Bundler version when specifying project dependencies.

Update a Ruby Gem

Similar to adding a Ruby gem.

Build the image:

docker build . -t mycargus/testrunner-base-ruby:latest

Now update the desired Ruby gem:

docker run --rm -v "$PWD:/usr/src/app" mycargus/testrunner-base-ruby:latest \
  bundle update --conservative <gem_name>

The --conservative flag prevents shared dependencies from getting updated. Now that you've updated the Gemfile.lock, you must re-build the Docker image:

docker build . -t mycargus/testrunner-base-ruby:latest

Run this project's tests

docker run --rm -it -v "$PWD:/usr/src/app" mycargus/testrunner-base-ruby:latest

License

See LICENSE for details.

mycargus / testrunner-base-ruby