Dockerfile for cryptpad that works behind port forwarding

cryptpad-dockerfile

FROM node:6

# Should run as non-root user but currently can't make it to work behind a reverse proxy. Alternatives are:
# 1) Change source to show a different websocket port than the one listened: https://github.com/xwiki-labs/cryptpad/issues/42
# 2) Tweak reverse proxy to rewrite GET /api/config responses
# 3) Expose server on port 80 within Docker container <-- simplest approach selected

# Create directories
RUN mkdir /data \
  && mkdir -p /usr/src/app \
#  && useradd --home-dir /usr/src/app --no-create-home user \
#  && chown -R user:user /data \
#  && chown -R user:user /usr/src/app \
  && npm install -g bower

#USER user

WORKDIR /usr/src/app

RUN git clone https://github.com/xwiki-labs/cryptpad.git . \
  && mv customize.dist customize \
  && rm customize/BottomBar.html \
  && npm install --unsafe-perm \
  && bower install --allow-root \
  && sed "s/Port: 3000/Port: 80/g" config.js.dist > config.js

EXPOSE 80

CMD [ "node", "server.js" ]