What is a Pipeline - A pipeline is a collection of steps or jobs interlinked in a sequence.

Declarative: Declarative is a more recent and advanced pipeline implementation as a code.

Scripted: Scripted was the first and most traditional pipeline implementation as a code in Jenkins. It was designed as a general-purpose DSL (Domain Specific Language) built with Groovy.

Why you should have a Pipeline

The definition of a Jenkins Pipeline is written into a text file (called a Jenkinsfile), which can be committed to a project’s source control repository.
This is the foundation of "Pipeline-as-code"; treating the CD pipeline as a part of the application to be versioned and reviewed like any other code.

Creating a Jenkinsfile and committing it to source control provides some immediate benefits:

• Automatically creates a Pipeline build process for all branches and pull requests.

• Code review/iteration on the Pipeline (along with the remaining source code).

Pipeline syntax

pipeline {
    agent any 
    stages {
        stage('Build') { 
            steps {
                // 
            }
        }
        stage('Test') { 
            steps {
                // 
            }
        }
        stage('Deploy') { 
            steps {
                // 
            }
        }
    }
}

Task

• Create a New Job, this time select Pipeline instead of Freestyle Project.

• Follow the Official Jenkins Hello World example

• Complete the example using the Declarative pipeline

1. to create a pipeline

1. configure settings add GitHub repo, select GitHub hook trigger for GITScm polling, and add pipeline script.

   

1. Done Now, run Build.

Happy learning!!!