How to combine Dockerfiles in gitlab ci? - docker

Question

I have this gitlab-ci.yml to build my SpringBoot app:
image: maven:latest
variables:
MAVEN_CLI_OPTS: "-s .m2/settings.xml --batch-mode"
MAVEN_OPTS: "-Dmaven.repo.local=.m2/repository"
cache:
paths:
- .m2/repository/
- target/
build:
stage: build
script:
- mvn $MAVEN_CLI_OPTS clean compile
only:
- /^release.*/
test:
stage: test
script:
- mvn $MAVEN_CLI_OPTS test
- "cat target/site/coverage/jacoco-ut/index.html"
only:
- /^release.*/
Now, i need to run another JOB on the Test Stage: Integration Tests. My app runs the integration tests on Headless Chrome with an in memory database, all i need to do on windows is: mvn integration-test
I've found a Dockerfile that has the Headless Chrome ready, so i need to combine the maven:latest image with this new image https://hub.docker.com/r/justinribeiro/chrome-headless/
How can i do that?

Answer 1

You can write a new docker file by choosing maven:latest as the base image. (That means all the maven latest image dependencies are there). You can refer this link to how to write a docker file.
Since the base image of the maven:latest is a debian image and docker file that contains Dockerfile that has the Headless Chrome is also a debian image so all the OS commands are same. So you can write a docker file like following where the base image is maven:latest and rest is same as here.
FROM maven:latest
LABEL name="chrome-headless" \
maintainer="Justin Ribeiro <justin#justinribeiro.com>" \
version="2.0" \
description="Google Chrome Headless in a container"
# Install deps + add Chrome Stable + purge all the things
RUN apt-get update && apt-get install -y \
apt-transport-https \
ca-certificates \
curl \
gnupg \
--no-install-recommends \
&& curl -sSL https://dl.google.com/linux/linux_signing_key.pub | apt-key add - \
&& echo "deb https://dl.google.com/linux/chrome/deb/ stable main" > /etc/apt/sources.list.d/google-chrome.list \
&& apt-get update && apt-get install -y \
google-chrome-beta \
fontconfig \
fonts-ipafont-gothic \
fonts-wqy-zenhei \
fonts-thai-tlwg \
fonts-kacst \
fonts-symbola \
fonts-noto \
ttf-freefont \
--no-install-recommends \
&& apt-get purge --auto-remove -y curl gnupg \
&& rm -rf /var/lib/apt/lists/*
# Add Chrome as a user
RUN groupadd -r chrome && useradd -r -g chrome -G audio,video chrome \
&& mkdir -p /home/chrome && chown -R chrome:chrome /home/chrome \
&& mkdir -p /opt/google/chrome-beta && chown -R chrome:chrome /opt/google/chrome-beta
# Run Chrome non-privileged
USER chrome
# Expose port 9222
EXPOSE 9222
# Autorun chrome headless with no GPU
ENTRYPOINT [ "google-chrome" ]
CMD [ "--headless", "--disable-gpu", "--remote-debugging-address=0.0.0.0", "--remote-debugging-port=9222" ]
I have checked this and it's working fine. Once you have write the Dockerfile you can build it using dokcer build . from the same repository as Dockerfile. Then you can either push this to docker hub or your own registry where your gitlab runner can access the docker image. Make sure you tag the docker image of your preference as example let's think the tag is and you are pushing to your local repository {your-docker-repo}/maven-with-chrome-headless:1.0.0
Then use that previous tag in your gitlab-ci.yml file as image: {your-docker-repo}/maven-with-chrome-headless:1.0.0

Answer 2

You do not "combine" docker containers. You put different services into different containers and run them all together. Look at kubernetes (it has now generic support in gitlab) or choose simpler solution like docker-compose or docker-swarm.
For integration tests we use docker-compose.
Anyway, if using docker-compose, you will probably fall into the situation that you need so-called docker-in-docker. It depends on the type of worker, you use to run your gitlab jobs. If you use shell executor, everything will be fine. If you are using docker executor, you will have to setup it properly, because you cant call docker from docker without additional manual setup.
If using several containers is not your choice and you definitely want to put all in one container, the recommended way is to use supervisor to launch processes inside container. One of the options is supervisord: http://supervisord.org/