title: Failed to discover available identity in OpenStack
body: <p>I have a little problem with OpenStack installation.
  When i use this:</p>
  
  <pre><code>openstack service list
  </code></pre>
  
  <p>the terminal return this error:</p>
  
  <pre><code>Failed to discover available identity versions when contacting 
  http://controller:35357/v3. Attempting to parse version from URL.
  Internal Server Error (HTTP 500)
  </code></pre>
  
  <p>what is the solution?</p>