title: Python Tkinter in Docker .TclError: couldn't connect to display
body: <p>I am new to python and am trying to build a small app. It needs to be a GUI app and I was wanting to containerise it with docker. I am getting the following error and can not find a solution</p>
  
  <pre><code>No protocol specified
  No protocol specified
  Traceback (most recent call last):
    File "tkinker.py", line 7, in &lt;module&gt;
      tinker = Tk()
    File "/usr/lib/python2.7/lib-tk/Tkinter.py", line 1818, in __init__
      self.tk = _tkinter.create(screenName, baseName, className, interactive, wantobjects, useTk, sync, use)
  _tkinter.TclError: couldn't connect to display ":0.0"
  </code></pre>
  
  <p>It starts locally but wont start in docker. My OS is Xubuntu.</p>
  
  <p>I have created a sample app (below), see run-test.sh <a href="https://github.com/jeremysells/test/tree/master/docker-tkinter" rel="nofollow">https://github.com/jeremysells/test/tree/master/docker-tkinter</a></p>