title: Fabric: rsync between two remote hosts
body: <p>I want rsync files from remote Production server to remote Backup server using Fabric.</p>
  
  <p>Server credentials stored in my local <code>~/.ssh/config</code></p>
  
  <pre><code>Host backup
       HostName 1.1.1.1
       Port 33333
       User swasher
  
  Host production
      HostName 2.2.2.2
      Port 44444
      User swasher
  </code></pre>
  
  <p>Now I want run rsync on Production machine, and I need insert host/user/name of Backup server in this command, something like this</p>
  
  <pre><code>@hosts('production')
  def backup():
      run("rsync -avz  -e 'ssh -p {PORT}' /from/ {USER}@{HOST}:/to/'.format(backup.PORT, backup.USER, backup.HOST))
  </code></pre>
  
  <p>How I can get credential of Backup server to run rsync?</p>