title: How can I get the free memory available on minions using on salt?
body: <p>I am looking for a simple way to get information about memory usage, like free memory form the salt minions.</p>
  
  <p>So far I know that the total memory can be listed using <code>salt '*' grains.items</code> but I don't even know how to list only just the total memory instead of the all grains data.</p>
  
  <p>Second problem is that I don't know how to get the free memory returned.</p>