title: how does docker use apt-get in mac?
body: <p>I have those lines in a <code>Dockerfile</code>:</p>
  <pre><code>RUN apt-get update &amp;&amp; apt-get install -y --no-install-recommends
    &lt;list of packages&gt;
  </code></pre>
  <p>I'm able to build a docker image via <code>docker build -f Dockerfile ...</code> in mac.</p>
  <p>given that mac doesn't have <code>apt-get</code>, how does that work under the hood? Particularly, if I run a linux container in macOS and there is a python script with a dependency on some package installed with apt-get, how is that dependency resolved in the Mac environment?</p>