title: How to debug a failed systemctl service (code=exited, status=217/USER)? [CentOS]
body: <p>I'm trying to configure Pterodactyl but the pteroq.service wont start [CentOS 8.0]</p>
  <pre><code>● pteroq.service - Pterodactyl Queue Worker
     Loaded: loaded (/etc/systemd/system/pteroq.service; enabled; vendor preset: disabled)
     Active: failed (Result: exit-code) since Sun 2020-08-23 09:35:28 IST; 6h ago
    Process: 753 ExecStart=/usr/bin/php /var/www/pterodactyl/artisan queue:work --queue=high,standard,low --sleep=3 --tries=3 &gt;
   Main PID: 753 (code=exited, status=217/USER)
   
  Aug 23 09:35:27 iface.ptro01 systemd[1]: pteroq.service: Main process exited, code=exited, status=217/USER
  Aug 23 09:35:27 iface.ptro01 systemd[1]: pteroq.service: Failed with result 'exit-code'.
  Aug 23 09:35:28 iface.ptro01 systemd[1]: pteroq.service: Service RestartSec=100ms expired, scheduling restart.
  Aug 23 09:35:28 iface.ptro01 systemd[1]: pteroq.service: Scheduled restart job, restart counter is at 5.
  Aug 23 09:35:28 iface.ptro01 systemd[1]: Stopped Pterodactyl Queue Worker.
  Aug 23 09:35:28 iface.ptro01 systemd[1]: pteroq.service: Start request repeated too quickly.
  Aug 23 09:35:28 iface.ptro01 systemd[1]: pteroq.service: Failed with result 'exit-code'.
  Aug 23 09:35:28 iface.ptro01 systemd[1]: Failed to start Pterodactyl Queue Worker.
  </code></pre>
  <p>my pteroq.service file [Unit File]:</p>
  <pre><code># Pterodactyl Queue Worker File
  # ----------------------------------
   
  [Unit]
  Description=Pterodactyl Queue Worker
  After=redis.service
   
  [Service]
  # On some systems the user and group might be different.
  # Some systems use `apache` or `nginx` as the user and group.
  User=www-data
  Group=www-data
  Restart=always
  ExecStart=/usr/bin/php /var/www/pterodactyl/artisan queue:work --queue=high,standard,low --sleep=3 --tries=3
   
  [Install]
  WantedBy=multi-user.target
  </code></pre>