Repository that explains how to create a custom jenkins image for Openshift (3.4) using Docker Build, S2I and Persistent volumes
OpenShift Jenkins Image Repository: https://github.com/openshift/jenkins

Jenkins is customisable using docker build (example in the directory Dockerfile). To do that, do the following steps:

1. Create a Dockerfile that extends the original openshift3/jenkins-2-rhel7

FROM openshift/jenkins-2-rhel7
COPY plugins.txt /opt/openshift/configuration/plugins.txt
RUN /usr/local/bin/install-plugins.sh /opt/openshift/configuration/plugins.txt

2. Build the image using the Dockerfile above

docker build -t docker.io/clrxm/custom-jenkins:latest .

3. Push the image in a docker registry

docker push docker.io/clrxm/custom-jenkins:latest

4. In OpenShift, create a new project

oc new-project custom-jenkins --display-name="Dockerfile Jenkins" --description="Demonstrate custom jenkins image with docker build"

5. Create an imageStream with your image (This will import all the tags).

oc import-image custom-jenkins --from=docker.io/clrxm/custom-jenkins --confirm --all

You can repeat this command to import new tags 6. Deploy Jenkins using the OpenShift jenkins template

oc new-app jenkins-ephemeral -p NAMESPACE=custom-jenkins -p JENKINS_IMAGE_STREAM_TAG=custom-jenkins:latest

As it is shown in the section "Latest Openshift Jenkins Image" you can directly build your docker image in Openshift if your dockerfile is available in a git repository.

oc new-build https://github.com/clerixmaxime/custom-jenkins.git \
   --context-dir=/Dockerfile --strategy=docker

1. Repeat steps 1, 2, & 3 above.
2. In OpenShift, create a new project

oc new-project custom-jenkins --display-name="Dockerfile Jenkins" --description="Demonstrate custom jenkins image with docker build"

3. Import the custom template under directory Dockerfile

oc create -f https://raw.githubusercontent.com/clerixmaxime/custom-jenkins/Dockerfile/jenkins-docker-image-template.yml

4. Deploy Jenkins. You have to specify the JENKINS_IMAGE to use as environement variable

oc new-app jenkins-master-s2i -p JENKINS_IMAGE=docker.io/clrxm/custom-jenkins:latest

You can use the S2I feature of OpenShift to build new Custom Jenkins Images. In order to include your modifications in Jenkins image, you need to have a Git repository with following directory structure:

• ./plugins folder that contains binary Jenkins plugins you want to copy into Jenkins
• ./plugins.txt file that list the plugins you want to install (see the section above)
• ./configuration/jobs folder that contains the Jenkins job definitions
• ./configuration/config.xml file that contains your custom Jenkins configuration

Note that the ./configuration folder will be copied into /var/lib/jenkins folder, so you can also include additional files (like credentials.xml, etc.).

1. Create a new project.

oc new-project custom-jenkins-s2i

2. Build the new custom-jenkins image using S2I jenkins image provided by OpenShift.

oc new-build jenkins:2~https://github.com/clerixmaxime/custom-jenkins.git --context-dir=/s2i --name=custom-jenkins

3. Deploy Jenkins using the OpenShift jenkins template

oc new-app jenkins-ephemeral \
     -p NAMESPACE=custom-jenkins-s2i  -p JENKINS_IMAGE_STREAM_TAG=custom-jenkins:latest

Building the last version of the openshift/jenkins image, an environment variable INSTALL_PLUGINS has been integrated that allows to provide a list of plugins. The image will install all these plugins at start up.

1. Create a new project.

oc new-project custom-jenkins-image

2. Get image in OpenShift

• Build the image directly in Openshift (This will build the image from a Dockerfile locate on a Git repository and create the ImageStream associated)

oc new-build https://github.com/openshift/jenkins.git \
   --context-dir=/1 --strategy=docker

• Import the image in Openshift as an ImageStream (The image has already been built and is available on my Docker Hub. Refer to ttps:https://github.com/openshift/jenkins to build the image on your own or retag my image and add it to your own registry)

oc import-image jenkins --from=docker.io/clrxm/jenkins-2-centos7 --confirm

3. Download the template jenkins-ephemeral-latest.json under s2i
4. Import the template

oc create -f jenkins-ephemeral-latest.json

5. Deploy Jenkins using this template

oc new-app jenkins-ephemeral-latest -p NAMESPACE=custom-jenkins-image -p JENKINS_IMAGE_STREAM_TAG=jenkins:latest -p INSTALL_PLUGINS=blueocean:1.0.1

You can also create a custom-jenkins image by mounting a persistent volume with the required plugins.

1. Create a Persistent Volume on OpenShift (Depends on your backing-storage solution)
2. Copy the required files (/plugins directory) in the persistent volume
   

/!\ The /plugins directory must contain all plugin dependencies

1. Create a new project.

oc new-project custom-jenkins-pv

1. Deploy Jenkins using the OpenShift jenkins-persistent template

oc new-app jenkins-persistent