title: Clone external private submodule with deploy token from Gitlab-CI
body: <p>I have a repository repoB on a private server serverB, and get a deploy token (user + password) from it.<br>
  This repository is used as a submodule in the project I'm trying to configure.</p>
  
  <p>In this project, I want to be able to init this submodule during the Gitlab-CI.</p>
  
  <p>My <code>.gitmodules</code> is:</p>
  
  <pre class="lang-none prettyprint-override"><code>[submodule "repoB"]
      path = repoB
      url = https://serverB/groupB/repoB.git
  </code></pre>
  
  <p>And I have in my <code>.gitlab-ci.yml</code>:</p>
  
  <pre class="lang-none prettyprint-override"><code>test_build:
      variables:
          GIT_SUBMODULE_STRATEGY: recursive
  </code></pre>
  
  <p>Actually, the error I get is the following (group: <code>japan7</code>, project: <code>nanachan</code>, repoB: <code>karaneko</code>, serverB: <code>git.inpt.fr</code>)</p>
  
  <p><a href="https://i.stack.imgur.com/l42c2.png" rel="noreferrer"><img src="https://i.stack.imgur.com/l42c2.png" alt="Error from the CI job"></a></p>
  
  <p>I suppose that I should put the deploy token user and password in the project secrets (in Settings −> CI / CD −> Variables) but I could not find the name of these variables, nor any help to solve this particular case.</p>
  
  <p>How should I proceed?<br>
  Thank you in advance for your help!</p>