The jobs should be able to skip the build

[arangamani]

The CI server currently builds a job for every single commit to master and pull requests. There are certain commits where we use the [skip ci] functionality provided by travis-ci to skip builds that only has non-functional changes but the cookbooks-ci doesn't currently has this feature.

Similar to the behavior of the travis CI, if either [ci skip] or [skip ci] is specified in the commit message, skip the CI build. This is not supported by default by the Jenkins Git plugin. But there is a simple plugin in Jenkins called Ci Skip which seems to work. It triggers a new build regardless of the commit message but the build finishes as NOT_BUILT if the commit message matches the skip regex. This is fine as long as it doesn't use any resources.

The following xml portion is added to the job configuration. This can simply be added to the job template in the buildWrappers section.

<buildWrappers>
  ...
  <ruby-proxy-object>
    <ruby-object ruby-class="Jenkins::Tasks::BuildWrapperProxy" pluginid="ci-skip">
      <pluginid pluginid="ci-skip" ruby-class="String">ci-skip</pluginid>
      <object ruby-class="CiSkipWrapper" pluginid="ci-skip">
        <ci__skip ruby-class="NilClass" pluginid="ci-skip"/>
      </object>
    </ruby-object>
  </ruby-proxy-object>
  ...
</buildWrappers>