How to use Dockerfile in Gitlab CI - docker

Question

Using gitlab-ci for my node/react app, I'm trying to use phusion/passenger-nodejs as the base docker image
I can specify this easily in .gitlab-ci.yml:
image: phusion/passenger-nodejs:latest
variables:
HOME: /root
cache:
paths:
- node_modules/
stages:
- build
- test
- deploy
set_environment:
stage: build
script:
- npm install
tags:
- docker
test_node:
stage: test
script:
- npm install
- npm test
tags:
- docker
However, Phusion Passenger expects you to make configuration changes, e.g. python support, using their special init process, etc. in the Dockerfile.
#FROM phusion/passenger-ruby24:<VERSION>
#FROM phusion/passenger-jruby91:<VERSION>
FROM phusion/passenger-nodejs:<VERSION>
#FROM phusion/passenger-customizable:<VERSION>
# Set correct environment variables.
ENV HOME /root
# Use baseimage-docker's init process.
CMD ["/sbin/my_init"]
# If you're using the 'customizable' variant, you need to explicitly opt-in
# for features.
#
# N.B. these images are based on https://github.com/phusion/baseimage-docker,
# so anything it provides is also automatically on board in the images below
# (e.g. older versions of Ruby, Node, Python).
#
# Uncomment the features you want:
#
# Ruby support
#RUN /pd_build/ruby-2.0.*.sh
#RUN /pd_build/ruby-2.1.*.sh
#RUN /pd_build/ruby-2.2.*.sh
#RUN /pd_build/ruby-2.3.*.sh
#RUN /pd_build/ruby-2.4.*.sh
#RUN /pd_build/jruby-9.1.*.sh
# Python support.
RUN /pd_build/python.sh
# Node.js and Meteor standalone support.
# (not needed if you already have the above Ruby support)
RUN /pd_build/nodejs.sh
# ...put your own build instructions here...
# Clean up APT when done.
RUN apt-get clean && rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*
Is there a way to use a Dockerfile with gitlab-ci? Is there a good work around other than apt-get install and adding shell scripts?

Answer 1

Yes, create a second Gitlab repository where you place your Dockerfile in. There you add a gitlab-ci.yml file with a script command that builds you modified image and push it to your private registry or the Gitlab embedded Docker registry, eg:
script:
docker build . -t http://myregistry:5000/mymodified image
docker push http://myregistry:5000/mymodified
Inside your other Gitlab repository, change the image: line accordingly:
image: http://myregistry:5000/mymodified
Information on the Gitlab embedded Docker registry can be found here -> here