title: Jenkins Pipeline pulls entire source code for jenkinsfile
body: <p>I was playing Jenkins 2.0 with multibranch pipeline with one master server plus a couple of slave nodes.  </p>
  
  <p>The <em>Jenkinsfile</em> looks like:</p>
  
  <pre><code>node('slave') {
      stage 'Checkout'
      checkout scm
      stage 'Build'
      ...
  }
  </code></pre>
  
  <p>We see that the plugin pulls the entire source code on the master node in order to get <em>Jenkinsfile</em> and then pull the entire source tree again on the slave nodes.  Is there a way to have the master only pull <em>Jenkinsfile</em>?</p>
  
  <p>Thanks.</p>