Jenkins Webhook Demo

Project Overview

This project demonstrates a minimal CI/CD setup using Jenkins and Docker that triggers a pipeline whenever a GitHub pull request is merged into the main branch. The setup is designed to be easy to run, clean, and educational.

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Features

• Jenkins runs in Docker with pre-installed plugins for Git and GitHub integration.
• Automatically creates a pipeline job on startup.
• Runs a sample Python script as a build step.
• Skips the Jenkins setup wizard and creates a default admin user.
• Persistent Jenkins home volume for data storage.

Prerequisites

• Docker
• Docker Compose
• GitHub repository (for webhook integration)

Getting Started

1. Clone this repository:

   git clone https://github.com/hitibash/jenkins-python-webhook.git
   cd jenkins-python-webhook

2. Build and start Jenkins using Docker Compose:

   docker-compose up --build

3. Access Jenkins:

   • Open http://localhost:8080 in your browser.
   • Login with username: admin, password: admin

4. Expose Jenkins to GitHub (for webhook delivery):

   If running Jenkins locally, you need to expose your local server to the internet so GitHub can reach it. You can use either ngrok or smee.io:

   • Using ngrok:

     1. Download ngrok and install it.
     2. Run the following command to forward port 8080:

        ngrok http 8080

     3. Copy the generated https://xxxx.ngrok.io URL.

   • Using smee.io:

     1. Go to https://smee.io and click "Start a new channel".
     2. Copy the generated smee URL (e.g., https://smee.io/your-channel-id).
     3. Install smee-client:

        npm install --global smee-client

     4. Forward events to your local Jenkins:

        smee -u https://smee.io/your-channel-id --target http://localhost:8080/github-webhook/

5. Configure GitHub Webhook:

   • Go to your GitHub repository settings.
   • Add a webhook pointing to your public URL (from ngrok or smee.io), e.g., https://xxxx.ngrok.io/github-webhook/ or your smee channel.
   • Set content type to application/json.
   • Choose "Let me select individual events" and select "Pull request".

6. Test the Pipeline:

   • Merge a pull request into the main branch of your repository.
   • The Jenkins pipeline should trigger and run the sample Python script.

File Structure

• dockerfile - Jenkins Docker image with Python and plugins.
• docker-compose.yml - Docker Compose configuration.
• plugins.txt - Jenkins plugins to install.
• scripts/disable_wizard.groovy - Disables Jenkins setup wizard and creates admin user.
• scripts/pipeline.groovy - Automatically creates the pipeline job.
• Jenkinsfile - Pipeline definition.
• main.py - Sample Python script.

Customization

• Edit main.py to change the script executed by the pipeline.
• Modify Jenkinsfile to add more build/test/deploy stages.
• Update scripts/pipeline.groovy to change job configuration.

Example Output

Jenkins Container Logs

To view Jenkins container logs, run:

docker compose logs jenkins

Pipeline Output

Open the job's "Console Output" in Jenkins to see the Python script executed by the pipeline:

Troubleshooting

• Ensure Docker and Docker Compose are installed and running.
• If Jenkins plugins fail to install, try rebuilding the image.
• For webhook issues, verify your Jenkins server is accessible from GitHub.
• Make sure your ngrok tunnel or smee.io forwarding service is running and actively forwarding requests to your local Jenkins instance.