Jenkins_Pipeline.txt

Backup
=========

Install a plugin called, 'ThinBackup'
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Jenkins Pipeline

In Jenkins we can create Jobs in 2 ways:
1) Free Style Project (Graphical User Interface)
2) Pipelines 

# Pipeline means set of stages and steps to automate build a project.
# Using Pipeline, we can handle complex projects and deployment tasks.

We can create a Pipeline in 2 ways:
1)Declarative Pipeline
2)Scripted Pipeline

============================================
Declarative Pipeline: Pipeline1

pipeline {
   agent any
   
   stages {
	 stage('Github') {
		steps {
		   echo 'This is stage 1.'
		}
	 }
	 
	 stage('Build') {
		steps {
		   echo 'This is stage 2.'
		}
	 }
	 
	 stage('Deploy') {
		steps {
		   echo 'This is stage 3.'
		}
	 }
   }
}
=============================================
Pipeline2
-------------
pipeline {
   agent any
   
   tools {
        // Install the Maven version configured as "M3" and add it to the path.
        maven "Maven 3.9.6"
   }
	
   stages {
	 stage('Github') {
		steps {
		   // Get some code from a GitHub repository
           git branch: 'main', url: 'https://github.com/madandevops2024/FedExProjectMar13.git'
		   
		   script {
			  try {
				sh 'make r'
		      } catch(Exception ex) {
				   echo 'In catch block, something went wrong in stage: Github'
		        }
		   }
		}
	 }
	 
	 stage('Build') {
		steps {
		   // Run Maven on a Unix agent.
           sh "mvn clean package"
		}
	 }	 
   }
}
================================================================
Pipeline3 - post stage
-----------------------
pipeline {
   agent any
   
   tools {
        // Install the Maven version configured as "M3" and add it to the path.
        maven "Maven 3.9.6"
   }
	
   stages {
	 stage('Github') {
		steps {
		   // Get some code from a GitHub repository
           git branch: 'main', url: 'https://github.com/madandevops2024/FedExProjectMar13.git'
		   
		   script {
			  try {
				sh 'make r'
		      } catch(Exception ex) {
				   echo 'In catch block, something went wrong in stage: Github'
		        }
		   }
		}
	 }
	 
	 stage('Build') {
		steps {
		   // Run Maven on a Unix agent.
           sh "mvn clean package"
		}
	 }	 
   }
   
   post {
	   always {
			echo "Always step has been executed"
	   }
	   
	   success {
			echo "Success step has been executed"
	   }
	   
	   failure {
			echo "Failure step has been executed"
	   }
   }
}
================================================================
Scripted Pipeline:
---------------------

node {      
	 stage('Github') {		
		   // Get some code from a GitHub repository
           git branch: 'main', url: 'https://github.com/madandevops2024/FedExProjectMar13.git'		  
	 }	 
	 
	 stage('Build') {
		def mavenHome = tool name:"Maven 3.9.6", type:"maven";
		def path ="${mavenHome}/bin/mvn";
		sh "${path} clean package";		
	 }	 
   }
}


========================
Multi-Branch Pipeline
------------------------

#Creating a seperate Jenkins Pipeline is difficult
# We can create one pipeline and we can build the code from the multiple branches at a time using 'MultiBranch Pipeline'

#It will scan all the branches in a git repository and it will execute pipeline for all the branches.
=====================================
Jenkins Shared Library
-------------------------

DevOps Engineers when they are working on various Pipeline scripts, normally the repeated tasks they will write in a seperate file inside a functions.

Groovy Language/Script

Jenkins Shared Library is a concept of having a common pipeline code in the version control system that can be used by any number of pipelines just by referencing the library available in the Github. 

Multiple teams can use the same shared library for their team.

1)Create a Repository for the Jenkins Shared Library
2) Folder Structure:
vars -> Important, create a 'vars' folder inside the repository.
src -> Source files
resources -> resources files
3)create below groovy file: (WelcomeMessage.groovy)
def call() {
	echo "Welcome to Jenkins Shared Library"
}

4) push the latest changes to Github repository
5)Manage Jenkins -> System -> Add the library name and branch name under 'Global Pipeline Libraries'

6) Add below statement in the pipeline:
@Library('Common-Jenkins-Shared-Library') _

7)Github Repository Path:
https://github.com/madandevops2024/Common-Jenkins-Shared-Library.git

8)
@Library('Common-Jenkins-Shared-Library') _

pipeline {
    agent any
	
    stages{
        stage('Welcome Message'){
            steps{
              WelcomeMessage()
            }
        }
		
        stage('Addition'){
            steps{
              script{
                  addition.add(10,10)
                  addition.add(20,20)
              }
            }
        }
    }
}
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