title: Ansible ad-hoc command with direct host specified - no hosts matched
body: <p>I am running a 16.04 Ubuntu desktop machine using VirtualBox. This VM has Ansible 2.4.0 installed. I am trying to run an ad-hoc ansible command just to prove it works (I am doing an online course). To simulate a small server farm, I use lxc (linux containters) and have three of them running:</p>
  
  <pre><code>root@tomasz-VirtualBox:/home/tomasz/ansible# lxc-ls --fancy
  NAME STATE   AUTOSTART GROUPS IPV4       IPV6 
  db1  RUNNING 0         -      10.0.3.248 -    
  web1 RUNNING 0         -      10.0.3.110 -    
  web2 RUNNING 0         -      10.0.3.226 -
  </code></pre>
  
  <p>I can SSH to any of these servers, however when I try to run a one-off ansible command, for example:</p>
  
  <pre><code>root@tomasz-VirtualBox:/home/tomasz/ansible# ansible 10.0.3.248 -m ping -u ubuntu
  </code></pre>
  
  <p>I get the following errors, that no inventory has been matched:</p>
  
  <pre><code> [WARNING]: No inventory was parsed, only implicit localhost is available
  
   [WARNING]: provided hosts list is empty, only localhost is available
  
   [WARNING]: Could not match supplied host pattern, ignoring: 10.0.3.248
  
   [WARNING]: No hosts matched, nothing to do
  </code></pre>
  
  <p>I am puzzled, to be honest, and as an Ansible novice, I have no idea how to move this forward. Seems such a simple issue, have not come across any similar thing here on stackoverflow. Many thanks for any hints!</p>