extend jenkins image to install maven

Question

I'm using the jenkins/jenkins:lts image at the moment. It runs fine and does everything I want to expect one thing. I want it to run Maven goals in the build steps. The problem is that there is not maven installed in the jenkins container environment.

So I want to extend the mentioned image to run an apt-get install maven.

My solution:

FROM "jenkins/jenkins:lts
USER root
RUN /bin/bash -c "apt-get install maven"

Will this be enough? I assume that all RUN and ENTRYPOINT steps of the jenkins image will run by itself and I do not need to re-execute them in my Dockerfile right?

Answer 1

According to the documentation, this would be in your dockerfile

FROM jenkins/jenkins:lts
# if we want to install via apt
USER root
RUN apt-get update && apt-get install -y maven
# drop back to the regular jenkins user - good practice
USER jenkins

Assuming your docker file is in your current directory this is how you would build the image and install in your local docker repo

docker build -t jenkins-maven .

For more information

https://github.com/jenkinsci/docker

After installing maven this way, the mvn version will probably be older than what you need. When I ran this, it was Apache Maven 3.3.9

Answer 2

Here is the simplest way to install maven into docker:

1. Connect to docker with root privilages

   sudo docker exec -u root -t -i [container-id] bash

2. update and install maven

   apt-get update & apt-get install

That's it.

Answer 3

Works file for me

FROM jenkins/jenkins:lts
USER root
RUN apt-get update && apt-get install -y maven

Answer 4

you need to update package cache before install, and don't miss -y for apt-get install.

FROM jenkins/jenkins:lts
RUN apt-get update && apt-get install -y maven