title: apache not working, shows a "404 page not found" error
body: <p>i have been trying to set up apache2 on my ubuntu 16.04 but after successful install i get a <code>404 page not found</code> error whenever i type localhost in the browser. I have uninstalled and installed apache2 several times but the problem still persists.
  This is the output of my /var/log/apache2/error.log file..</p>
  
  <blockquote>
    <p>[Tue Jun 26 02:20:52.809104 2018] [mpm_event:notice] [pid 1010:tid 139925306578816] AH00491: caught SIGTERM, shutting down
    [Tue Jun 26 02:20:58.753357 2018] [mpm_event:notice] [pid 1359:tid 139843231913856] AH00489: Apache/2.4.18 (Ubuntu) configured -- resuming normal operations
    [Tue Jun 26 02:20:58.753554 2018] [core:notice] [pid 1359:tid 139843231913856] AH00094: Command line: '/usr/sbin/apache2'</p>
  </blockquote>