title: One Jenkinsfile for multi project git repository
body: <p>My developers team want to use a single GIT repo to store several microservices as it is more convenient to only synchronise one repo.</p>
  
  <p>Unfortunately, all Jenkins pipeline litterature i've found always show a Jenkinsfile at the root of a repo holding only one microservice.</p>
  
  <p>If we consider the following git repository structure:</p>
  
  <pre><code>MyProject
           ¦-&gt; Microservice1
           ¦                ¦-&gt; src/main/java/...
           ¦                ¦-&gt; src/main/docker/Dockerfile
           ¦
           ¦-&gt; Microservice2 (etc.)
           ¦-&gt; Microservice3 (etc.)
           ¦
           ...
           ¦-&gt; Jenkinsfile
  </code></pre>
  
  <p>How can I detect inside the jenkinsfile which Microservices projects were updated in order to execute de pipeline on those projects only?                               </p>