Jenkins Pipelines are a suite of plugins that support implementing and integrating continuous delivery pipelines into Jenkins. A pipeline is a series of automated steps that Jenkins uses to build, test, and deploy software. This topic will cover the basics of Jenkins Pipelines, their components, and how to create and manage them.

1. Pipeline: A user-defined model of a continuous delivery pipeline. It is a series of steps that Jenkins will execute.
2. Node: A machine that Jenkins runs on. Pipelines can run on multiple nodes.
3. Stage: A block that contains a series of steps. Stages help to visualize the pipeline process.
4. Step: A single task that Jenkins executes. Steps can be commands, scripts, or other actions.

Jenkins supports two types of pipelines:

1. Declarative Pipeline: A more structured and simpler syntax for defining pipelines. It is designed to make writing and reading pipeline code easier.
2. Scripted Pipeline: A more flexible and powerful syntax based on Groovy. It allows for more complex and dynamic pipeline definitions.

Here is a simple example of a declarative pipeline:

• pipeline: The block that defines the entire pipeline.
• agent any: Specifies that the pipeline can run on any available agent.
• stages: A block that contains all the stages of the pipeline.
• stage('Build'), stage('Test'), stage('Deploy'): Individual stages of the pipeline.
• steps: The actual tasks to be executed within each stage.

Here is a simple example of a scripted pipeline:

• node: The block that defines the node on which the pipeline will run.
• stage('Build'), stage('Test'), stage('Deploy'): Individual stages of the pipeline.
• echo 'Building...', echo 'Testing...', echo 'Deploying...': The actual tasks to be executed within each stage.

Create a Jenkins pipeline that includes the following stages:

1. Checkout: Checkout the code from a Git repository.
2. Build: Compile the code.
3. Test: Run unit tests.
4. Deploy: Deploy the application.

• git 'https://github.com/your-repo/your-project.git': Checks out the code from the specified Git repository.
• sh 'make build': Runs the build command.
• sh 'make test': Runs the test command.
• sh 'make deploy': Runs the deploy command.

• Syntax Errors: Ensure that the pipeline syntax is correct. Use the Jenkins Pipeline Syntax tool to generate correct syntax.
• Agent Specification: Always specify an agent for the pipeline to run on.
• Stage Names: Use meaningful names for stages to make the pipeline easier to understand.
• Error Handling: Implement error handling to manage failures gracefully.

Understanding Jenkins Pipelines is crucial for automating the build, test, and deployment processes. By mastering both declarative and scripted pipelines, you can create robust and flexible CI/CD pipelines. In the next topic, we will delve deeper into using Jenkins plugins to extend the functionality of your Jenkins instance.