title: trouble using systemd for autostart in Python/Tkinter on Beaglebone
body: <p>I am unable to enable a systemd autostart service for a python script on the Beaglebone running Debian Jessie. I am using Tkinter in my script. Here is my unit file code:</p>
  
  <pre><code>[Unit]
  Description=Startup OQY
  
  [Service]
  WorkingDirectory=/home/debian/oqy
  ExecStart=/usr/bin/python oqy.py
  SyslogIdentifier=oqy
  
  [Install]
  WantedBy=multi-user.target
  </code></pre>
  
  <p>and here is the status error</p>
  
  <pre><code>● oqy.service - Startup OQY
     Loaded: loaded (/lib/systemd/system/oqy.service; enabled)
     Active: failed (Result: exit-code) since Wed 2016-04-06 16:40:35 UTC; 2min 58s ago
    Process: 10739 ExecStart=/usr/bin/python oqy.py (code=exited, status=1/FAILURE)
   Main PID: 10739 (code=exited, status=1/FAILURE)
  
  Apr 06 16:40:35 beaglebone oqy[10739]: Traceback (most recent call last):
  Apr 06 16:40:35 beaglebone oqy[10739]: File "oqy.py", line 270, in &lt;module&gt;
  Apr 06 16:40:35 beaglebone oqy[10739]: main()
  Apr 06 16:40:35 beaglebone oqy[10739]: File "oqy.py", line 252, in main
  Apr 06 16:40:35 beaglebone oqy[10739]: root = tk.Tk()
  Apr 06 16:40:35 beaglebone oqy[10739]: File "/usr/lib/python2.7/lib-tk/Tkinter.py", line 1813, in __init__
  Apr 06 16:40:35 beaglebone oqy[10739]: self.tk = _tkinter.create(screenName, baseName, className, interactive, wantobjects, useTk, sync, use)
  Apr 06 16:40:35 beaglebone oqy[10739]: _tkinter.TclError: no display name and no $DISPLAY environment variable
  Apr 06 16:40:35 beaglebone systemd[1]: oqy.service: main process exited, code=exited, status=1/FAILURE
  Apr 06 16:40:35 beaglebone systemd[1]: Unit oqy.service entered failed state.
  </code></pre>
  
  <p>What am I doing wrong?</p>
  
  <p><strong>UPDATE:</strong> Systemd services configure system services. The GUI has to wait until the display server and display manager have started, so I shouldn't be using systemd at all.</p>