title: How does the new Docker --squash work
body: <p>In <strong>Docker 1.13</strong> the new <strong>--squash</strong> parameter was added.</p>
  <p>I'm now hoping to reduce the size of my images as well as being able to &quot;hide&quot; secret files I have in my layers.</p>
  <p>Below you can now see the difference from doing a build with and without the --squash parameter.</p>
  <p><strong>Without Squash</strong></p>
  <p><a href="https://i.stack.imgur.com/ktjwg.jpg" rel="noreferrer"><img src="https://i.stack.imgur.com/ktjwg.jpg" alt="enter image description here" /></a></p>
  <p><strong>With Squash</strong></p>
  <p><a href="https://i.stack.imgur.com/wZQIQ.jpg" rel="noreferrer"><img src="https://i.stack.imgur.com/wZQIQ.jpg" alt="enter image description here" /></a></p>
  <p><strong>Now to my question.</strong></p>
  <p>If I add a secret file in my <strong>first</strong> layer, then use the secret file in my <strong>second</strong> layer, and the finally remove my secret file in the <strong>third</strong> layer, and then build with the --squash flag.</p>
  <p>Will there be <strong>any way</strong> now to get the secret file?</p>