technonotes-hacker

Posted on Oct 12, 2023

Jenkins - Day - 3

Pipeline concept

Select Pipeline Project after giving the name.

Pull the code " https://github.com/tkdhanasekar/jenkins-python.git "

Save the project and build now.

Jenkins File

pipeline {
  agent any
  stages {
    stage('version') {
      steps {
        sh 'python3 --version'
      }
    }
    stage('hello') {
      steps {
        sh 'python3 hello.py'
        sh 'python3 world.py'
      }
    }
  }
}

Python File 1

print('Hello DevOps')

Python File 2

print('Hello World')

Console Output

Pipeline Logs

Let's Try with "https://github.com/Zulaikha12/git-test"

Create Project & Add the Git , START to EXPLORE

Its trying to Check & Gets into ERROR , so this is where we need to provide the FILE NAME.

Lets Change & Execute one by one

Jenkinsfile.txt

pipeline {
    agent any

    stages {
        stage('Build') {
            steps {
                echo 'Building.. This is the build phase'
            }
        }
        stage('Test') {
            steps {
                echo 'Testing.. This is the testing phase'
            }
        }
        stage('Deploy') {
            steps {
                echo 'Deploying....  This is the deployment phase'
            }
        }
    stage('Postdeploy') {
        steps {
            echo 'Postdeployment phase....'
        }
    }
    }
}

Markdown inside the script & Paste the script rather than calling the file name in GIT

Jenkinsfile1.txt

pipeline {
    agent any
    stages {
        stage('Build') {
            steps {
                sh 'echo "Hello World"'
                sh '''
                    echo "Multiline shell steps works too"
                    ls -lah
                '''
            }
        }
    }
}

From where this "ls -lah" got executed ? [TBD]

Passing SH script

Jenkinsfile2.txt

pipeline {
    agent any
    stages {
        stage('Deploy') {
            steps {
                retry(3) {
                    sh './flakey-deploy.sh'
                }

                timeout(time: 3, unit: 'MINUTES') {
                    sh './health-check.sh'
                }
            }
        }
    }
}

ERROR:
+ ./flakey-deploy.sh
/var/lib/jenkins/workspace/pipeline_Zulaikha12_Jenkinsfile2@tmp/durable-1c6bcb96/script.sh: 1: ./flakey-deploy.sh: not found

Whether we need to keep the script over this location ? [TBD]

Usage of POST in the Pipeline script

Jenkinsfile3.txt

pipeline {
    agent any
    stages {
        stage('Test') {
            steps {
                 echo 'Fail!'; exit 1
            }
        }
    }
    post {
        always {
            echo 'This will always run'
        }
        success {
            echo 'This will run only if successful'
        }
        failure {
            echo 'This will run only if failed'
        }
        unstable {
            echo 'This will run only if the run was marked as unstable'
        }
        changed {
            echo 'This will run only if the state of the Pipeline has changed'
            echo 'For example, if the Pipeline was previously failing but is now successful'
        }
    }
}

Approve or Reject

Jenkinsfile4.txt

pipeline {
    agent any

    stages {
        stage('Input') {
            steps {
                input('Do you want to proceed?')
            }
        }

        stage('If Proceed is clicked') {
            steps {
                print('hello')
            }
        }
    }
}

Writing scipt in Panel

script.txt

pipeline{
    agent any
    stages{
        stage("dev"){
            echo"This is DEV environment"
        }
        stage("UAT"){
            echo"Testing in UAT"
        }
        stage("PROD"){
            echo"Go-live"
        }
    }
}

Apply and Save

Important Points to be Remembered

What is SCM ?

In Jenkins, SCM stands for "Source Code Management". This option instructs Jenkins to obtain your Pipeline from Source Control Management (SCM), which will be your locally cloned Git repository.