title: How do I mount --bind inside a Docker container?
body: <p>I have this container based on <code>debian:jessie</code> (but this is not very relevant as I had the same issue with <code>alpine:3.3</code>). I get to the point where I need to</p>
  
  <pre><code>mount --bind /htdocs/www /home/user/example.com/www
  </code></pre>
  
  <p>and I get</p>
  
  <pre><code>mount: permission denied
  </code></pre>
  
  <p>I can't find anything in any kernel log, and <code>-vvv</code> yields nothing interesting. I obviously can do this on the host (with any other pair of subtree/node). In my example above /htdocs/www is the mountpoint of a Docker volume, but it doesn't appear like it's of any importance, as I can't <code>mount --bind</code> any pair of subtree/node inside the container.</p>