title: Gitlab: add all users to all groups without changing permisions of existing users
body: <p>In GitLab you can add all users to all groups with a simple command:</p>
  
  <pre><code> gitlab-rake gitlab:import:all_users_to_all_groups
  </code></pre>
  
  <p>After execution the GitLab <em>Users</em> became <strong>developers</strong> and GitLab <em>administrators</em> become <strong>owners</strong> of each group. If there were existing users in the group with different permissions, the permissions are discarded with this command.</p>
  
  <p>The question is if there is a command to add all users to all groups where: </p>
  
  <ul>
  <li>command would add only the users which are not already in the group or</li>
  <li>command would add all users, but remain existing permissions which were already attributed to the users in the groups</li>
  </ul>