Dockerfile CMD not running at container start - bash

Question

So i've written a Dockerfile for a project, i've defined a CMD to run on starting the container to bootstrap the application.
The Dockerfile looks like
# create our mount folders and volumes
ENV MOUNTED_VOLUME_DIR=sites
RUN mkdir /$MOUNTED_VOLUME_DIR
ENV PATH=$MOUNTED_VOLUME_DIR/sbin:$MOUNTED_VOLUME_DIR/common/bin:$PATH
RUN chown -Rf www-data:www-data /$MOUNTED_VOLUME_DIR
# Mount folders
VOLUME ["/$MOUNTED_VOLUME_DIR/"]
# Expose Ports
EXPOSE 443
# add our environment variables to the server
ADD ./env /env
# Add entry point script
ADD ./start.sh /usr/bin/startContainer
RUN chmod 755 /usr/bin/startContainer
# define entrypoint command
CMD ["/bin/bash", "/usr/bin/startContainer"]
The start.sh script, does some git stuff like cloning the right repo, setting environment vars, as well as starting supervisor.
The start script begins with this
#!/bin/bash
now=$(date +"%T")
echo "Container Start Time : $now" >> /tmp/start.txt
/usr/bin/supervisord -n -c /etc/supervisord.conf
I start my new container like this
docker run -d -p expoPort:contPort -t -i -v /$MOUNTED_VOLUME_DIR/$PROJECT:/$MOUNTED_VOLUME_DIR $CONTAINER_ID /bin/bash
when i login to the container i see that supervisor hasn't been started, and neither has nginx or php5-fpm. the /tmp/start.txt file with a timestamp set from the startContainer script doesn't exist, showing its never ran the CMD in the Dockerfile.
Any hints on to get this fixed would be great

Answer 1

This:
docker run -d -p expoPort:contPort -t -i -v /$MOUNTED_VOLUME_DIR/$PROJECT:/$MOUNTED_VOLUME_DIR $CONTAINER_ID /bin/bash
Says 'run /bin/bash' after instantiating the container. E.g. skip CMD.
Try this:
docker run -d -p expoPort:contPort -t -i -v /$MOUNTED_VOLUME_DIR/$PROJECT:/$MOUNTED_VOLUME_DIR $CONTAINER_ID