Setting up CI pipeline with Jenkins, GitHub & Docker on Ubuntu (Linux) machine

Pre-requisites

You should know Docker, basic concept of CI/CD& basic of what Jenkins is used for

You should have Linux OS like Ubuntu, Java (OpenJDK 11) & Docker installed

Description

This project was created to install Jenkins on a local machine (Ubuntu 16.04) and create a basic pipeline with GitHub & Docker

We will be doing is

• Installing Jenkins and running it, on a local machine
• Creating a docker image
• Pushing it to docker hub using Jenkins’ pipeline

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Installing Jenkins

1. Add repository keystream

wget -q -O — https://pkg.jenkins.io/debian-stable/jenkins.io.key | sudo apt-key add -
You must get a response printed as `OK`

2. Now add the Debian package to your sources.list

sudo sh -c ‘echo deb https://pkg.jenkins.io/debian-stable binary/ > /etc/apt/sources.list.d/jenkins.list’

3. Now, update the system

sudo apt update

4. Finally, install Jenkins

sudo apt install jenkins

Now, Jenkins is installed in your system and is ready to run.

Start, stop, and status of Jenkins service

We would be using standard systemctl commands

• To start

sudo systemctl start jenkins

• To check status

sudo systemctl status jenkins

• To stop

sudo systemctl stop jenkins

• To start on boot

sudo systemctl enable jenkins

First-time login

1. Go to <IP_ADDRESS>:8080

2. Jenkins login page should appear asking you to enter the administrator password

3. Now open a terminal and type

sudo cat /var/lib/jenkins/secrets/initialAdminPassword

A string printed on the console is the administrator password, enter this is on Jenkins login page

4. Choose Install selected plugins (You may choose Select plugins to install)
Now it will install plugins and show you the details, it takes some time

5. It would ask you to create a new ‘Admin User’.

Now, Jenkins is configured for the system

Integrating GitHub with Jenkins

1. Go to Manage Jenkins from the menu on the left pane

2. Click on Manage Plugins

3. Go to Advance tab

4. Search & install GitHub Integration, Pipeline, Docker & Docker Pipeline plugins

a. Click on Download now and install after restart

b. On the next window select the checkbox Restart Jenkins when the installation is complete and no jobs are running at the bottom of the page. Jenkins will restart once the plugin is downloaded

5. Now go to your GitHub repository, go to Settings, go to Webhooks, click on Add Webhook

6. For the payload URL, provide your Jenkins URL and the GitHub webhook path at the end of the URL — https://<JENKINS_URL>/github-webhook/

7. Content-type should be JSON

8. In Which events would you like to trigger this webhook? select Just the push event

Now we are ready to integrate any GitHub repository with Jenkins

Creating Pipeline

1. On the dashboard, click on Create Job option

2. Give a name to your pipeline

3. Choose Pipeline

4. In Build Triggers select GitHub hook trigger for GITScm polling

5. In the Pipeline section choose definition as Pipeline script from SCM

6. In the SCM (Source Code Management ) tab, select Git enter GitHub repository URL, and save

7. Now copy this Jenkinsfile in your repository base path

8. Add Docker credentials to Jenkins host

a. On the top right of the home page, click on the dropdown next to the username

b. Select Credentials

c. Go to System OR click on Global from anyone pre-existing credentials

d. Click on Add Credentials

e. Keep scope Global

f. Enter Docker Hub username & password and set some ID

9. Now in the Jenkinsfile in the environment set the ID

The pipeline is now created, push code to GitHub to see the pipeline run

GitHub Repository