title: Running gitlab-ci pipeline jobs as non-root user
body: <p>I have a <code>mvn</code> project  which must be build as an non-root user
  but by default gitlab-ci allows runners to run as root user.
  I'm using <code>gitlab.com</code> runners by setting up <code>gitlab-ci.yml</code> file.
  I tried creating a user and switching to it like this:</p>
  
  <pre><code>$ useradd ***
  $ su -***
  $ whoami
  root
  </code></pre>
  
  <p>It still says I'm root.
  How can I solve this?</p>