Jenkins in Docker

This project is about how to setup jenkins master and slave in a docker and kubernetes environment.

Build Step

1. Build the image of jenkins-master in ./master folder

   docker build -t="{{IMAGE_NAME}}" ./master

2. Build the image of jenkins-master in ./slave folder

   docker build -t="{{IMAGE_NAME}}" ./slave

3. Push those images to docker hub

Run in Docker

*** slave is not available here since it is used for distributed builds in different machines ***

Requirement:

• docker
• docker-compose

#####Start Jenkins server

docker run -d -p 8080:8080 \
 	-v /var/run/docker.sock:/var/run/docker.sock \
	-v $(which docker):/usr/bin/docker \
 	-v $(which docker-compose):/usr/bin/docker-compose \
	{{JENKINS_MASTER_IMAGE_NAME}}

Remind: All the docker/docker-compose operation in Jenkins require sudo

#####Test whether setup properly

Open a new jobs in Jenkins and execute sudo docker run hello-world and check the console output.

Integration to Kubernetes

1. Move the jenkins-master.yaml and jenkins-slave.yaml to the host machine.

2. Create a folder to store the Jenkins master data

mkdir -p /var/jenkins
chmod -R 777 /var/jenkins

3. Edit jenkins-master.yaml and jenkins-slave.yaml to use the correct image if you have built a new image. Moreover, make sure the path of docker and docker-compose in volumes is correct.

4. Start the Jenkins master server - kubectl create -f jenkins-master.yaml

5. Access Jenkins through its address, you can get it through kubectl describe svc jenkins

6. Configurate jenkins according to the instruction

7. Edit the env in jenkins-slave.yaml. Change the value of variable according to your setting in previous step.

8. Start the Jenkins slave - kubectl create -f jenkins-slave.yaml

9. You can scale the number of slave later - kubectl scale rc jenkins-controller --replicas={{new number}}

###Why don't use environment variable in yaml

Giving users the power to customize the env to the app is better than customizing the app to the env

• One of the kubernetes members