Added docker container.

Dockerfile

+FROM rabbitmq:3-management
+
+EXPOSE 15672
+EXPOSE 1883
+
+# Define the location of the pid file
+ENV RABBITMQ_PID_FILE /var/lib/rabbitmq/mnesia/rabbitmq
+
+# Set up start script
+COPY ./files/start.sh /usr/local/bin
+CMD /usr/local/bin/start.sh

README.rst

@@ -3,8 +3,8 @@ Docker the-engine message bus
 =============================
 
 This is a Docker container for a main message bus for instances of
-`the-engine <https://github.com/openstreetmap/osm2pgsql>`__ based on 
-`rabbitmq <https://www.rabbitmq.com/>`__.
+`the-engine <https://gitext.gfz-potsdam.de/dynamicexposure/the-engine/the-engine>`__
+based on `rabbitmq <https://www.rabbitmq.com/>`__.
 
 Copyright and copyleft
 ----------------------

files/start.sh

+#!/bin/sh
+
+# Create a user for rabbitmq
+( rabbitmqctl wait --timeout 60 $RABBITMQ_PID_FILE ; \
+rabbitmqctl add_user $RABBITMQ_USER $RABBITMQ_PASSWORD 2>/dev/null ; \
+rabbitmqctl set_user_tags $RABBITMQ_USER administrator ; \
+rabbitmqctl set_permissions -p / $RABBITMQ_USER  ".*" ".*" ".*" ; \
+echo "*** User '$RABBITMQ_USER' with password '$RABBITMQ_PASSWORD' completed. ***" ; \
+echo "*** Log in the WebUI at port 15672 (example: http://localhost:15672) ***") &
+
+rabbitmq-plugins enable rabbitmq_mqtt
+# $@ is used to pass arguments to the rabbitmq-server command.
+# For example if you use it like this: docker run -d rabbitmq arg1 arg2,
+# it will be as you run in the container rabbitmq-server arg1 arg2
+rabbitmq-server $@

vars

+# Define a user for the messaging bus queue
+ENV RABBITMQ_USER test
+
+# Set password for the user of the the messaging bus queue
+ENV RABBITMQ_PASSWORD test
+