title: Ho to fix the `getaddrinfo ENOTFOUND marketplace.visualstudio.com` when running a vs code project in Dev Container mode (with proxy pac and VPN)
body: <p><strong><em>Given:</em></strong></p>
  
  <ol>
  <li>machine connected through VPN (SitePoint) to company private network</li>
  <li>vscode runs with the proxy pac configuration switch <code>--proxy-pac-url=http://&lt;myhostname&gt;/&lt;path_to_proxypac&gt;/proxy.pac"</code>: </li>
  <li><p>any extensions can be seen and installed successfully</p></li>
  <li><p>python 3 project opened with vscode</p></li>
  <li>development container configuration files... (Python 3) added to project</li>
  <li><p>Add the following extensions to .devcontainer.json</p>
  
  <pre><code>  "extensions": [
      "ms-python.python",
      "himanoa.python-autopep8",
      "wholroyd.jinja",
      "magicstack.MagicPython",
    ]
  </code></pre></li>
  <li>Reopened project in container</li>
  </ol>
  
  <p><strong><em>Expected:</em></strong></p>
  
  <ul>
  <li>extensions configured in .devcontainer.json are successfully installed in the Dev Container mode vs code.</li>
  </ul>
  
  <p><strong><em>Actual:</em></strong></p>
  
  <ol>
  <li>the list of <code>DEV CONTAINER: PYTHON 3 - INSTALLED</code> is empty</li>
  <li>and got the following error in vs code terminal</li>
  </ol>
  
  <pre><code>    [27528 ms] Installing extensions...
      [27528 ms] getaddrinfo ENOTFOUND marketplace.visualstudio.com
      getaddrinfo ENOTFOUND marketplace.visualstudio.com
      getaddrinfo ENOTFOUND marketplace.visualstudio.com
      getaddrinfo ENOTFOUND marketplace.visualstudio.com
      [27528 ms] Exit code 1
  </code></pre>
  
  <p><strong><em>Mentions:</em></strong>
  1. I can install extensions from Dev Container mode vs code.</p>
  
  <p><strong><em>What am I supposed to do to address this problem?</em></strong></p>
  
  <p><strong><em>Could this be an issue or feature request for <code>Remote-Containers</code> extension?</em></strong></p>