How to install Jenkins on Kubernetes

Kubernetes Linux Ubuntu

Introduction

Jenkins — is a continuous integration server that is distributed open source in the Java language. In this publication we will install this CI using kubernetes clusters.
Kubernetes is software for orchestrating containerized applications - automating their deployment, scaling, and coordination in a cluster environment. Thanks to containerization, you can easily restrict applications from each other, as well as change the allocated server resources from one application to another if needed.

In Serverspace, you can create a ready-made Kubernetes cluster, because it is convenient!

Cloud Servers from €4 / moIntel Xeon Gold 6254 3.1 GHz CPU, SLA 99,9%, 100 Mbps channel

Requirements

At least 2 CPUs to implement a kubernetes server
Or rent a kubernetes server
Client server, for managing and configuring kubernetes clusters

Preinstallation

Before installing CI, you need to deploy Kubernetes. To do this in Serverspace infrastructure, simply log in to your personal account, then go to Kubernetes and start the installation:

Configure the dedicated cluster according to the characteristics you need, don't forget to give it a name.

P.s It will take about 15 minutes to create the cluster, be patient.

After creating the cluster, you will be able to download the configuration file of the server with Cubernetes. You will need this config file later when installing CI, to link the client-server and the server with the kubernetes clusters.

Download the configuration file to your computer, upload it to the server by choosing one of the suggested solutions:

You can create a new file and put the kubernetes cluster config into it.

nano config-kubernetes

Insert the kubernetes config file into the created file and save it.

You can upload the file remotely using the SFTP protocol.

Getting started

Install the necessary packages for the CI installation.

sudo apt-get update && sudo apt-get install -y apt-transport-https

curl -s https://packages.cloud.google.com/apt/doc/apt-key.gpg | sudo apt-key add -

echo "deb https://apt.kubernetes.io/ kubernetes-xenial main" | sudo tee -a /etc/apt/sources.list.d/kubernetes.list

sudo apt-get update

sudo apt-get install -y kubectl

Specify the location of the k8s server configuration file.

export KUBECONFIG=<your path to config>

P.s. We copied/created this file after starting the kubernetes server.

Check the connection to the server.

kubectl cluster-info

Create a space for CI.

kubectl create namespace <your_namespace>

To install and run CI on a Kubernetes server, we need to create a configuration file, with our server settings.

nano our_project_jen.yaml

Enter these parameters into the created configuration file.

apiVersion: apps/v1

kind: Deployment

metadata:

name: jenkins

spec:

replicas: 1

selector:

matchLabels:

app: jenkins

template:

metadata:

labels:

app: jenkins

spec:

containers:

- name: jenkins

image: jenkins/jenkins:lts

ports:

- name: http-port

containerPort: 8080

- name: jnlp-port

containerPort: 50000

volumeMounts:

- name: jenkins-vol

mountPath: /var/jenkins_vol

volumes:

- name: jenkins-vol

emptyDir: {}

This configuration file will deploy the latest CI release. Also the ports specified in the configuration will be created and opened, you can change them to what you need.

Now point the created space which configuration file to use.

kubectl create -f jenkins.yaml --namespace <your_namespace>

Wait for the cluster to install the jenkins image and run it, use the command below to test the module.

kubectl get pods -n jenkins

After running the image, I will create two more services to use the web version of jenkins.
Create and modify the service configuration file.

nano jenkins-service.yaml

Add these settings to the created file.

Point cluster to use this configuration file with the same space created.