title: Add button to Django admin index page
body: <p>I want to add a site-wide action to Django admin, called "Synchronize SQL-KB".
  <a href="https://i.stack.imgur.com/B3Ztc.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/B3Ztc.jpg" alt="Site-wide button &quot;Synchronize SQL-KB&quot;"></a></p>
  
  <p>For that I have copied locally <code>templates/admin/index.html</code> file from Django and modified it as follows:</p>
  
  <pre><code>...
  {% if app_list %}
      &lt;table&gt;
          &lt;tr&gt;
              &lt;td&gt;
                  &lt;a href="sync-sql-kb/"&gt;Synchronize SQL-KB&lt;/a&gt;
              &lt;/td&gt;
          &lt;/tr&gt;
      &lt;/table&gt;
      {% for app in app_list %}
      ...
  </code></pre>
  
  <p>So as you can see I want the link button to trigger a request to <code>/admin/sync-sql-kb/</code>.</p>
  
  <p>How to register this URL now? Where and how to implement a handler function?</p>
  
  <p>Note that this situation in my view differs from other SO questions in that the action is site-wide, rather than bound to a specific Django model.</p>