How to display output in a simple dockerized Python application?

Question

I just started using docker and am still struggling a bit in it's usage. I have a python simple python application that uses Matplotlib to generate some simple graphs. I currently have the following Dockerfile:

FROM python:2

COPY requirements.txt /    
RUN pip install --requirement requirements.txt   
COPY my_code.py /

CMD [ "python", "./my_code.py" ]

This however generates the following error:

Traceback (most recent call last):
  File "./fraud_detection_sample_code.py", line 161, in <module>
    plt.figure(1)
  File "/usr/local/lib/python2.7/site-packages/matplotlib/pyplot.py", line 535, in figure
    **kwargs)
  File "/usr/local/lib/python2.7/site-packages/matplotlib/backends/backend_tkagg.py", line 81, in new_figure_manager
    return new_figure_manager_given_figure(num, figure)
  File "/usr/local/lib/python2.7/site-packages/matplotlib/backends/backend_tkagg.py", line 89, in new_figure_manager_given_figure
    window = Tk.Tk()
  File "/usr/local/lib/python2.7/lib-tk/Tkinter.py", line 1820, in __init__
    self.tk = _tkinter.create(screenName, baseName, className, interactive, wantobjects, useTk, sync, use)
_tkinter.TclError: no display name and no $DISPLAY environment variable

What would be the best way to solve this? Is it even possible with my approach?

Answer 1

Could you test this?

docker run -ti --rm -e DISPLAY=$DISPLAY -v /tmp/.X11-unix:/tmp/.X11-unix your_image_name

It worked for me in a similar project. Idea from here