Jenkins Shared Library

A reusable Jenkins Shared Library built to simplify and standardize CI/CD pipeline automation across multiple projects. This library provides modular Groovy scripts for common DevOps tasks such as Docker image build & push, kubectl installation, and Kubernetes deployment.

By centralizing reusable pipeline logic, this project improves maintainability, scalability, and consistency in Jenkins-based automation workflows.

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Features

• Reusable Jenkins Shared Library architecture
• Modular Groovy pipeline scripts
• Git repository checkout automation
• Docker image build and registry push
• Kubectl installation in Jenkins agent
• Kubernetes deployment automation
• Reduced code duplication across Jenkins pipelines
• Scalable CI/CD workflow integration

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Repository Structure

JENKINS-SHARED-LIBRARY/
│
├── vars/
│   ├── gitCheckout.groovy
│   ├── dockerBuildAndPush.groovy
│   ├── installKubectl.groovy
│   └── k8sDeploy.groovy
│
└── README.md

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Module Description

1. gitCheckout.groovy

Handles Git repository checkout from a specified branch.

Purpose:

• Clone source code from Git repository
• Support reusable SCM checkout logic
• Simplify Jenkins pipeline setup

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2. dockerBuildAndPush.groovy

Automates Docker image creation and pushes the image to a container registry.

Purpose:

• Build Docker images
• Tag images
• Push images to Docker Hub / private registry
• Standardize containerization workflow

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3. installKubectl.groovy

Installs and configures kubectl on the Jenkins agent.

Purpose:

• Install kubectl dynamically
• Ensure Kubernetes CLI availability
• Support deployment automation

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4. k8sDeploy.groovy

Applies Kubernetes manifests for application deployment.

Purpose:

• Deploy deployment.yaml
• Deploy service.yaml
• Manage Kubernetes rollout process
• Simplify cluster deployment execution

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Example Jenkins Pipeline Usage

@Library('jenkins-shared-library') _

pipeline {
    agent any

    stages {

        stage('Checkout Source') {
            steps {
                script {
                    gitCheckout('main')
                }
            }
        }

        stage('Build & Push Docker Image') {
            steps {
                script {
                    dockerBuildAndPush()
                }
            }
        }

        stage('Install Kubectl') {
            steps {
                script {
                    installKubectl()
                }
            }
        }

        stage('Deploy to Kubernetes') {
            steps {
                script {
                    k8sDeploy('kubeconfig-credential-id')
                }
            }
        }
    }
}

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CI/CD Workflow

This shared library supports the following automation flow:

1. Checkout application source code
2. Build Docker image
3. Push image to container registry
4. Install kubectl on Jenkins agent
5. Connect to Kubernetes cluster
6. Deploy manifests (deployment.yaml, service.yaml)
7. Release application

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Tech Stack

• Jenkins Shared Library
• Groovy
• Jenkins Pipeline
• Git
• Docker
• Docker Registry
• Kubernetes
• Kubectl
• CI/CD
• DevOps Automation

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Benefits of This Shared Library

• Centralized reusable pipeline logic
• Cleaner Jenkinsfiles
• Reduced repetitive scripting
• Faster CI/CD implementation
• Easier maintenance across projects
• Better deployment consistency
• Improved scalability for enterprise workflows

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Developed to demonstrate reusable Jenkins Shared Library design for scalable CI/CD automation using Docker and Kubernetes.