title: docker build and publish plugin usage
body: <p>I have jenkins running as Docker container, I tried to install jenkins build and publish plugin here and copied Dockerfile inside jenkins workspace, but whenever I run the build, it gives me:</p>
  
  <pre><code>Started by user Jenkins Admin
  Building in workspace /var/lib/jenkins/jobs/workspace
  [workspace] $ docker build -t index.docker.io/test/openshift:latest --pull=true /var/lib/jenkins/jobs/test/workspace
  ERROR: Cannot run program "docker" (in directory "/var/lib/jenkins/jobs/workspace"): error=2, No such file or directory
  java.io.IOException: Cannot run program "docker" (in directory "/var/lib/jenkins/jobs/workspace"): error=2, No such file or directory
      at java.lang.ProcessBuilder.start(ProcessBuilder.java:1048)
      at hudson.Proc$LocalProc.&lt;init&gt;(Proc.java:244)
      at hudson.Proc$LocalProc.&lt;init&gt;(Proc.java:216)
      at hudson.Launcher$LocalLauncher.launch(Launcher.java:803)
      at hudson.Launcher$ProcStarter.start(Launcher.java:381)
  
  Build step 'Docker Build and Publish' marked build as failure
  Finished: FAILURE
  </code></pre>
  
  <p>could you please tell me why is that so?</p>