title: Permission denied inside Docker container
body: <p>I have a started container <code>gigantic_booth</code> and I want to create the directory <code>/etc/test</code>:</p>
  
  <pre><code># docker exec -it gigantic_booth /bin/bash
  $ mkdir /etc/test
  $ mkdir: cannot create directory '/etc/test': Permission denied
  </code></pre>
  
  <p>And <code>sudo</code> command is not found. I don't want to create this directory in image-build-time but once is started.</p>
  
  <p>How can I do?</p>
  
  <p>Thanks :)</p>