DevOps Classroomnotes 22/Jul/2023

Pipeline as Code

• This is expressing CI/CD pipleine in terms of some code/expressions/statements
• This is part of version control i.e. each change done to the steps will have history
• Refer Here for official docs
• Azure DevOps

# Starter pipeline
# Start with a minimal pipeline that you can customize to build and deploy your code.
# Add steps that build, run tests, deploy, and more:
# https://aka.ms/yaml

trigger:
- main

pool:
  name: Default
steps:
  - task: Maven@3
    inputs:
      mavenPOMFile: 'pom.xml'
      goals: 'package'
      publishJUnitResults: true
      testResultsFiles: '**/surefire-reports/TEST-*.xml'
      testRunTitle: 'unittests'

• Jenkins

node("JDK-11-MVN") {
  stage("get-code") {
    sh " git clone https://github.com/spring-projects/spring-petclinic.git && cd spring-petclinic"
  }
  stage("build") {
    sh "mvn package"
    junit '**/surefire-reports/TEST-*.xml'
  }
}

• The only manual work would be to go to jenkins and create a pipeline project and configure where your pipeline is

Pipeline as Code in Jenkins

• Jenkins has two flavours
  • Scripted Pipeline
    • This was developed where you can execute groovy language directly
  • Declartive Pipeline
    • Jenkins has created a DSL (Domain specific Language) which is mostly inspired from traditional jenkins

Create a Scripted Pipeline

• Create a game of life project
  
  
• Pipeline can be written directly or can be chosen from source code management
  
• Open pipeline syntax
• Created the following structure
  
• Sample pipeline

node('JDK_8') {
    stage('git') {
        git branch: 'master', url: 'https://github.com/dummyrepos/game-of-life-july23.git'
    }
    stage('build') {
        sh 'mvn package'
    }
    stage('reporting') {
        archiveArtifacts artifacts: '**/gameoflife.war', followSymlinks: false
        junit '**/surefire-reports/TEST-*.xml'
    }
}

Create a Declartive Pipeline

• This has different structure in pipeline not for creating the project
  
• We have written

pipeline {
    agent { label 'JDK-17' }
    stages {
        stage('git') {
            steps {
                git branch: 'main', url: 'https://github.com/dummyrepos/spring-petclinic-1.git'
            }
        }
        stage('build') {
            steps {
                sh 'mvn package'
            }
        }
    }

}

Scripted Pipelines

• Generally we create a file called as Jenkinsfile
• Basic structure: Refer Here
  
• For all the steps Refer Here
• In scripted and declartive pipelines when we install plugins we get extra steps.

Declarative Pipelines

• Here also we create a file called as Jenkinsfile
• Basic structure: Refer Here for official docs of jenkins
  

Lets create a declarative pipeline by exploring most options in Declarative pipeline

• Refer Here for the repo
• Lets create a develop branch
• We have developed the basic skeleton

pipeline {
    agent { label 'JDK-17' }
    options {
        timeout(time: 30, unit: 'MINUTES')
    }
    triggers {
        pollSCM('* * * * *')
    }
    tools {
        jdk 'JDK_17'
    }
    stages {
        stage('vcs') {
            steps {

            }
        }
        stage('build and package') {
            steps {

            }
        }
        stage('reporting') {
            steps {

            }
        }
    }

}

• Now using pipeline steps reference Refer Here lets do the build
• git Refer Here
• and also other steps as done in the class
• Refer Here for the changeset
• Create a project and build now
  
  
• Build result
  

Note:

• Create a free account in mailtrap Refer Here
• Exercise: Create a declarative pipeline
  • for spring petclinic
  • for game of life