Jenkins Training Docker Container

A Jenkins container with auto-installed plugins.

Latest Jenkins container derived from official Jenkins Docker Image with automatic plugin installation and environment enhancements. Mainly used for training purposes, but serves as well as a nicely configured starting point for other experiments.

Features

The image contains a lot of plugins pre-installed. It also contains docker binaries, such that docker images can be started "within" (sibling mode) the Jenkins container once the docker socket from host is mapped.

Important notice regarding Docker Support: To make docker builds and runs available, I took the approach to make docker and docker-compose binaries suid root, which means they will be executed with a user id of 0 (root). This approach should work on all platforms including Docker Desktop for Mac / Windows, which is not the case when using a docker system group approach. Please be aware of the possible security issues involved with having highly privileged executables being run from Jenkins, as well as giving access to Docker deamon on the Docker host in general by mounting the docker socket into the Jenkins container!

Usage

Start Jenkins Container

Suggested commandline:

docker run -p 10080:8080 --name jenkins -v jenkins_home:/var/jenkins_home -v /var/run/docker.sock:/var/run/docker.sock rgielen/jenkins-training

The options explained:

• docker run is your base command. If not available locally, the image will be pulled. Then is will be started in attached mode.
• -p 10080:8080 maps the container port 8080 to 10080 on your host. Chose a port different from 10080 if you like.
• --name jenkins gives the container the name jenkins. Chose any name you like or omit it if you like hashes of random naming ;)
• -v jenkins_home:/var/jenkins_home creates and maps a docker data container named jenkins_home to the container mount point /var/jenkins_home. Alternatively you might want to mount a host directory instead. See Manage data in containers for details.
• -v /var/run/docker.sock:/var/run/docker.sock mounts the host's docker socket for usage within the container. This enables the docker client within the container to start docker containers on the host using sudo Be careful with this option, since basically the container gains root access to your host.
• rgielen/jenkins-training is the name of the image to run.

Stop Jenkins Container

When following the commandline above, you will be running in attached mode. The container is configured to shut down gracefully on Ctrl-C, so here you go. docker stop jenkins will stop the container, given you named it jenkins, from any other shell or when running in detached mode.

Using Jenkins Container

Browser Access On Docker Toolbox

Docker basically runs in a VirtualBox virtual machine on your physical machine. To access the running container, you need to know the IP address of the virtual machine. When you started your machine earlier, this machine address was echoed during startup. To find this out later, use docker-machine env default. The IP address you are looking for is the one echoed in the DOCKER_HOST line.

Usually the address will be 192.168.99.100. Given this is the case, and given you chose port 10080 in the start command above, you can now open a browser window with the URL http://192.168.99.100:10080.

Browser Access On Docker Native

Given you chose port 10080 in the start command above, you can now open a browser window with the URL http://localhost:10080.

First time startup

You will be prompted for an initial setup password. You find the password in the console output from your running Jenkins container. Look for something similar to

*************************************************************
*************************************************************
*************************************************************

Jenkins initial setup is required. An admin user has been created and a password generated.
Please use the following password to proceed to installation:

94b0c926a101440388062e30ab3f2626

This may also be found at: /var/jenkins_home/secrets/initialAdminPassword

*************************************************************
*************************************************************
*************************************************************

This is the password you are looking for.

Afterward, setup an admin user as desired.

Last you will be presented with a choice to install default or specific plugins. Chose as you like. Most plugins will be installed already, so the this step should end quickly.

Create Jobs

Go ahead and configure Jenkins as you like and create new Jobs.

Updating the image

To receive the latest image, run docker pull rgielen/jenkins-training before next container start.

Source code and Issues

The sources are found on GitHub. Please also report issues there.