Jenkins Declarative Pipeline

So, Lets go deep into Jenkins and learn to start Pipeline in Jenkins. First let basics of Pipeline and all stuffs.

What is a Pipeline?

A pipeline is a sequence of steps or jobs that are interconnected. These steps automate the process of building, testing, and deploying applications, ensuring that your code goes through a consistent workflow every time changes are made.

Declarative vs. Scripted Pipelines

In Jenkins, there are two main types of pipelines:

• Declarative Pipeline: This is a more recent and advanced way to define your pipeline. It’s simpler, more readable, and designed to provide a more straightforward experience.

• Scripted Pipeline: This was the first implementation of pipeline as code in Jenkins. It uses Groovy-based DSL (Domain-Specific Language) and offers more flexibility, but can be complex and harder to maintain.

Why Use a Pipeline?

Implementing a Jenkins pipeline provides several benefits:

1. Pipeline as Code: The pipeline is defined in a text file called a . This file is versioned and reviewed like any other code in your project.

2. Automation: Automatically creates a pipeline build process for all branches and pull requests.

3. Code Review: Facilitates code review and iteration on the pipeline along with the source code.

4. Consistency: Ensures a consistent build, test, and deployment process across all environments.

Jenkins Declarative Pipeline Syntax

Here’s a basic structure of a Jenkins Declarative Pipeline:

Key Components:

• Agent: Defines where the pipeline should run.

• Stages: Represents a sequence of stages to be executed.

• Steps: Defines the actual tasks to be performed in each stage.

Creating Your First Declarative Pipeline

Let's get hands-on! Today’s task is to create a new Jenkins job using the Declarative Pipeline.

Step-by-Step Guide:

1. Create a New Job: Open your Jenkins dashboard. Click on "New Item". Enter a name for your job and select "Pipeline" as the project type

2. Follow the Official Jenkins Hello World Example: Refer to the Jenkins Pipeline Syntax for the Hello World example.

3. Complete the Example: Your should look something like this:

Script: Enter the following Declarative Pipeline script:

4. Save and Run:

• Save your job configuration.

• Click "Build Now" to run the pipeline.