Learn how Jenkins automates software builds, testing, integration, delivery, and deployment using pipelines, Jenkinsfiles, stages, agents, and plugins.
Jenkins Pipeline
Source Code
Build Application
Run Tests
Package Application
Deploy Application
Introduction
Jenkins is an automation platform commonly used to build Continuous Integration and Continuous Delivery pipelines.
Jenkins Pipelines allow teams to define software delivery workflows as code. A Pipeline can include stages for building, testing, packaging, and deploying applications.
Pipelines are commonly stored in a file called aJenkinsfile, allowing the automation process to be versioned alongside the application source code.
Core Concepts
Jenkins Pipelines combine stages, steps, agents, source control, and plugins to automate different parts of the software delivery lifecycle.
A Jenkins Pipeline defines an automated software delivery process. It can model stages such as building, testing, packaging, and deployment.
Key Topics
A Jenkinsfile contains the definition of a Jenkins Pipeline and can be stored in source control alongside the application code.
Key Topics
Stages organize a Pipeline into logical phases such as Build, Test, Security Scan, Package, and Deploy.
Key Topics
Steps are individual tasks that Jenkins executes inside a stage, such as running shell commands, tests, or other automation actions.
Key Topics
Jenkins Architecture
The Jenkins controller manages the Jenkins environment, coordinates jobs, and schedules Pipeline execution.
An agent provides an execution environment where Jenkins jobs and Pipeline stages can run.
A Pipeline defines the complete automation process used to build, test, and deliver software.
A logical section of a Pipeline representing a specific phase of the delivery process.
An individual operation that Jenkins performs as part of a Pipeline.
Plugins extend Jenkins with integrations, build tools, source control support, notifications, cloud platforms, and additional functionality.
Pipeline as Code
A Jenkinsfile is a text file containing the definition of a Jenkins Pipeline. It can be committed to the same source control repository as your application.
This approach allows your CI/CD workflow to be reviewed, versioned, updated, and maintained as part of the software project.
Jenkins supports both Declarative Pipeline and Scripted Pipeline syntax. Declarative syntax provides a structured approach, while Scripted Pipeline offers more flexibility for advanced use cases.
Example Project Structure
my-project/ │ ├── src/ │ ├── package.json │ ├── README.md │ └── Jenkinsfile
Your First Pipeline
This example shows a simple Declarative Pipeline with stages for checking out source code, building the application, running tests, and preparing for deployment.
Each stage contains one or more steps that Jenkins executes on the configured agent.
Jenkinsfile
pipeline {
agent any
stages {
stage('Checkout') {
steps {
checkout scm
}
}
stage('Build') {
steps {
sh 'npm ci'
sh 'npm run build'
}
}
stage('Test') {
steps {
sh 'npm test'
}
}
stage('Deploy') {
steps {
echo 'Deploying application'
}
}
}
}Pipeline Execution
A developer pushes code or creates a change in the source control repository.
Jenkins starts the configured job or Pipeline based on a trigger or manual action.
Jenkins allocates an available execution environment for the Pipeline or stage.
The Pipeline runs build commands, tests, validation, and other automation tasks.
A successful build can create artifacts, packages, or container images.
The final Pipeline stages can deploy the validated application to the required environment.
Use Cases
Jenkins can automate many tasks throughout the software development and delivery lifecycle.
Automatically build and test software changes whenever developers push code to a repository.
Automate the software delivery process and prepare validated application builds for deployment.
Run automated unit tests, integration tests, and other validation processes as part of a Pipeline.
Build container images and integrate container workflows into your CI/CD pipeline.
Automate deployments to cloud infrastructure, virtual machines, Kubernetes environments, or other platforms.
Run recurring jobs for backups, maintenance, reports, monitoring, or other scheduled tasks.
Learning Roadmap
Follow these steps to move from Jenkins fundamentals to building complete CI/CD pipelines.
Learn how Jenkins is used for automation and understand the role of controllers, agents, jobs, and plugins.
Create a simple Jenkins job and run basic build or automation commands.
Understand Pipeline syntax and how stages and steps define an automated workflow.
Define your Pipeline in a Jenkinsfile and store it in your application's source code repository.
Automate dependency installation, application builds, tests, linting, and other validation processes.
Combine source control, builds, tests, containerization, and deployment into a complete automated delivery pipeline.
Best Practices
Store Pipeline definitions in source control so CI/CD workflows can be versioned and reviewed with the application code.
Use descriptive names for stages and organize automation into logical parts of the delivery process.
Store passwords, tokens, keys, and other sensitive values using Jenkins credential management instead of hardcoding them.
Keep build, test, security, packaging, and deployment processes separated for easier troubleshooting.
Configure appropriate agents and execution environments for different workloads and Pipeline stages.
Review build logs, test results, failures, and Pipeline execution history to identify issues quickly.
Continue Learning
Learn Continuous Integration, Continuous Delivery, pipelines, testing, and automated software delivery.
⚡Learn how to automate builds, testing, workflows, and deployments directly from your GitHub repository.
⚙️Understand DevOps culture, collaboration, automation, and modern software delivery practices.
Next Step
Practice creating Jenkinsfiles, defining stages, running builds, executing tests, using agents, and building complete CI/CD automation workflows.