added more fine-grained control of custom_before_steps

Author: skoef

README.md

@@ -85,7 +85,7 @@ Gitlab CI uses a .gitlab-ci.yml file in the root of your repository tell Gitlab
 | custom_jobs    |Define custom Gitlab CI jobs that will be executed. It is recommended that you use this option if you need customized Gitlab CI jobs. Please see the [.gitlab-ci.yml](https://docs.gitlab.com/ce/ci/yaml/README.html) docs for specifics.|
 | rubygems_mirror | Use a custom rubygems mirror url |
 | image          |Define the Docker image to use, when using the Docker runner. Please see the [Using Docker images](https://docs.gitlab.com/ee/ci/docker/using_docker_images.html) docs for specifics.|
-| custom_before_steps |Allows you to pass additional steps to the GitLab CI before_script. Please see the [.gitlab-ci.yml](https://docs.gitlab.com/ce/ci/yaml/#before_script-and-after_script) docs for specifics.|
+| custom_before_steps |Allows you to pass additional steps to the GitLab CI before_script. Please see the [.gitlab-ci.yml](https://docs.gitlab.com/ce/ci/yaml/#before_script-and-after_script) docs for specifics. If given as an array, the steps are executed _before_ the default steps of the before_script. If you want to have more control over the execution order of the steps, you can define a hash with a `before` and/or `after` key holding an array of steps to be executed before and after the default_script respectively.|
 | default_before_script  |If false, removes the default `before_script` section. Useful if you need a customised Bundler install, or to remove Bundler entirely. If the key is unset the default behaviour is to add `before_script`.|
 |use_litmus| By default it is disabled. Set to `true` to configure travis to use Litmus testing tool for acceptance testing jobs with default values.|
 |litmus|Allows you to update default config values. Its sub keys are `provision_list`, `puppet_collection`, `ruby_version`, `install_wget` which are detailed below.|

moduleroot/.gitlab-ci.yml.erb

@@ -50,8 +50,13 @@ default:
 <% if !configs.has_key?('default_before_script') || configs['default_before_script'] -%>
   before_script: &before_script
 <% if configs['custom_before_steps'] -%>
-<%   configs['custom_before_steps'].each do |step| -%>
+<%   if configs['custom_before_steps'].is_a? Array -%>
+<%     configs['custom_before_steps'] = { 'before' => configs['custom_before_steps'] } -%>
+<%   end -%>
+<%   if configs['custom_before_steps']['before'] -%>
+<%     configs['custom_before_steps']['before'].each do |step| -%>
     - <%= step %>
+<%     end -%>
 <%   end -%>
 <% end -%>
     - bundle -v
@@ -68,6 +73,11 @@ default:
     - gem --version
     - bundle -v
     - bundle install <%= configs['bundler_args'] %>
+<% if configs['custom_before_steps'] and configs['custom_before_steps']['after'] -%>
+<%     configs['custom_before_steps']['after'].each do |step| -%>
+    - <%= step %>
+<%     end -%>
+<%   end -%>
 <% end -%>
 
 <% if configs['ruby_versions'] -%>