title: How to install mcrypt on Docker
body: <p>I have a Docker Container with Phalcon3 and php 7. I am trying to install the php extension Mcrypt without luck.</p>
  
  <p>If I do ssh to the container, and execute:</p>
  
  <pre><code>apt-get update
  apt-get install php7.0-mcrypt  
  </code></pre>
  
  <p>I get the following:</p>
  
  <pre><code>E: Unable to locate package php7.0-mcrypt
  E: Couldn't find any package by regex 'php7.0-mcrypt'
  </code></pre>
  
  <p>Is there a way to get it installed?</p>