title: Create reusable concourse pipelines
body: <p>I have a bunch of applications that follow the same basic pattern so I'm trying to create a pipeline that would act as a reusable library.  So far it's working pretty good by doing something like:</p>
  
  <pre><code>fly -t TARGET set-pipeline /n /c Pipelines\WindowsApp.yml ^
      /l ..\Secrets\config.yml /p %PRODUCT%-%BRANCH% ^
      --var productname=%PRODUCT% --var branch=%BRANCH%
  </code></pre>
  
  <p>It's working great so far but one thing I don't see is  what if I want to execute a step for one scenario but not another.   Is there a way to apply a condition to a step?  I am able to pass the variables into my run steps and act upon them in a shell script but that seems to defeat the purpose of using resources and steps if I go down that road.</p>