Including entrypoint.sh to run xvfb to simulate an X Server.

tests/Dockerfile

@@ -1,12 +1,25 @@
 FROM txgio/anki
 
+USER root
+RUN apt-get update
+RUN apt-get install -y xvfb
+USER anki-user
+
 RUN mkdir -p /home/anki-user/Documents/Anki/addons
 
 COPY AnkiConnect.py /home/anki-user/Documents/Anki/addons
 
 # Required if you want to access it from another IP address.
-# RUN sed -i 's/127.0.0.1/0.0.0.0/' /home/anki-user/Documents/Anki/addons/AnkiConnect.py
+RUN sed -i 's/127.0.0.1/0.0.0.0/' /home/anki-user/Documents/Anki/addons/AnkiConnect.py
 
 COPY tests/prefs.db /home/anki-user/Documents/Anki/prefs.db
 
+ADD tests/entrypoint.sh /entrypoint.sh
+
+USER root
+RUN chmod +x /entrypoint.sh
+USER anki-user
+
+ENTRYPOINT ["/entrypoint.sh"]
+
 CMD /bin/bash -c "(/usr/bin/ibus-daemon -xd; /usr/bin/anki;)"

tests/entrypoint.sh

@@ -0,0 +1,8 @@
+#!/usr/bin/env bash
+set -e
+
+# Start Xvfb
+Xvfb -ac -screen scrn 1280x2000x24 :99.0 &
+export DISPLAY=:99.0
+
+exec "$@"