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 implementation of a pipeline as a code.

Scripted: Scripted was the first and most traditional implementation of the pipeline 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 in turn 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 a number of 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-01

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

  Create a Jenkins declarative pipeline select new items > pipeline and give the pipeline name.

  

  

  

  Pipeline:

  The Declarative pipeline should start with the pipeline block and this is the mandatory block.

  Agent:

  Agent signifies where the Jenkins build job should run. In this case, we have selected agents as any.

  Stages:

  stages block consists of different executable stage blocks. we have name stage “Hello”.

  Steps:

  Steps blocks consist of the actual operation which needs to be performed inside Jenkins.

  we are printing “Hello World“.

You can manually build the project by clicking on "Build Now".

Thank you for reading this blog!

Happy learning!