Module 8 - Build Automation & CI/CD with Jenkins

This repository contains a demo project created as part of my DevOps studies in the TechWorld with Nana – DevOps Bootcamp.

https://www.techworld-with-nana.com/devops-bootcamp

Demo Project: Configure Webhook to trigger CI Pipeline automatically on every change

Technologies used: Jenkins, GitHub, Git, Docker, Java, Maven

Project Description:

• Install GitHub Plugin in Jenkins
• Configure GitHub access token and connection to Jenkins in GitHub project settings
• Configure Jenkins to trigger the CI pipeline, whenever a change is pushed to GitHub

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Step 1 — Install GitHub Plugins in Jenkins

Verify the following plugins are installed before proceeding:

Plugin	Purpose
GitHub Plugin	Core GitHub integration
GitHub Integration	Enables webhook-based triggers
GitHub Branch Source Plugin	Required for multibranch pipelines

How to check / install:

1. Go to Manage Jenkins → Plugins → Installed plugins
2. Search for each plugin by name
3. If missing, switch to the Available tab, find the plugin, and install it

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Step 2 — Configure GitHub Access Token & Server Connection

2a. Add a GitHub Server in Jenkins

1. Go to Manage Jenkins → System → scroll to the GitHub section
2. Click Add GitHub Server and fill in:

Field	Value
Name	GitHub
API URL	https://api.github.com

2b. Create a GitHub Personal Access Token

1. Navigate to https://github.com/settings/tokens/new
2. Set the Note to jenkins
3. Select the following scopes:

Scope	Reason
admin:repo_hook	Create, read, and delete webhooks
public_repo	Access public repositories
repo:status	Update commit statuses

Note: Add the repo scope only if you need access to private repositories.

2c. Add the Token as a Jenkins Credential

1. In the GitHub Server config, click Add next to Credentials → Jenkins
2. Choose Secret text and fill in:

Field	Value
ID	github-token
Scope	Global
Secret	<your generated token>

3. Click Test connection — you should see Credentials verified
4. Check Manage hooks so Jenkins can auto-create webhooks on GitHub
5. Click Save

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Step 3 — Trigger CI Pipeline on Push

3a. Create the Jenkins Pipeline Job

1. Go to Dashboard → New Item
2. Name it pipeline and select Pipeline

General tab:

• Check GitHub project
• Repo URL: https://github.com/explicit-logic/jenkins-module-8.4

Build Triggers tab:

• Check GitHub hook trigger for GITScm polling

Pipeline tab:

Field	Value
Definition	Pipeline script from SCM
SCM	Git
Repository URL	https://github.com/explicit-logic/jenkins-module-8.4
Credentials	github (GitHub username + password/token)
Branch	*/pipeline
Script Path	Jenkinsfile

3. Click Save

3b. Add a Webhook in GitHub

1. Navigate to your repo → Settings → Webhooks → Add webhook
2. Configure it as follows:

Field	Value
Payload URL	http://<DROPLET_IP>:8080/github-webhook/
SSL verification	Disabled
Events	Just the push event

3. Click Add webhook

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Step 4 — Configure a Multibranch Pipeline

A multibranch pipeline automatically discovers branches and pull requests, creating a pipeline job for each.

4a. Create the Multibranch Pipeline Job

1. Go to Dashboard → New Item
2. Name it multibranch, select Multibranch Pipeline, click OK

Branch Sources:

• Click Add source → GitHub

Field	Value
Credentials	github
Repository HTTPS URL	https://github.com/explicit-logic/jenkins-module-8.4

• Click Validate to confirm access

Behaviors — click Add and include:

• Discover branches
• Discover pull requests from origin

Build Configuration:

• Script Path: Jenkinsfile

Scan Multibranch Pipeline Triggers:

• Check Periodically if not otherwise run → set interval to 1 day

3. Click Save — Jenkins will scan the repository and create jobs for each branch