Automate Jenkins Build with GitHub Webhook on Amazon Linux 2

🎯 Project Objective

Automate your Jenkins CI pipeline using GitHub webhooks so that any git push to the repository triggers a Jenkins job — removing manual build triggers.

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🧰 Tools Used

• Amazon EC2 (Amazon Linux 2)

• Jenkins

• GitHub

• Maven (Optional, if you're building a Java project)

• Ngrok (To expose local Jenkins to GitHub Webhooks)

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🚀 Step-by-Step Guide

1️⃣ Ensure Jenkins is Running

• Jenkins should be accessible on your EC2 instance via http://<public-ip>:8080

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2️⃣ Install GitHub Plugin in Jenkins

• Go to: Manage Jenkins → Plugin Manager → Available

• Search & install: GitHub Integration Plugin, GitHub Branch Source Plugin

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3️⃣ Set Up a Jenkins Job for Your GitHub Repo

• New Item → Freestyle Project

• Under Source Code Management, choose Git

• Add your GitHub repo URL

• Use credentials if private repo

• In Build Triggers, check: ✅ GitHub hook trigger for GITScm polling

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4️⃣ Expose Jenkins to the Internet (Temporary) Using Ngrok

Jenkins is running on EC2, but GitHub needs a public HTTPS URL. Use ngrok.

• Download Ngrok on your local machine

• Expose Jenkins:

    ngrok http 8080
  

• Copy the HTTPS URL like https://abcd1234.ngrok.io

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5️⃣ Update GitHub Webhook

• Go to your GitHub Repo → Settings → Webhooks

• Click Add webhook

  • Payload URL: https://abcd1234.ngrok.io/github-webhook/

  • Content type: application/json

  • Events: ✅ Just the push event

  • Click Add webhook

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6️⃣ Test the Webhook

• Make a small change in your GitHub repo (e.g., edit README)

• Push it:

    git add .
    git commit -m "Trigger Jenkins build"
    git push
  

• Go to Jenkins — you should see the job running automatically! 🚀

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✅ Expected Outcome

• Jenkins job is triggered automatically every time code is pushed to the GitHub repo.

• No manual triggering required anymore.