Configure Jenkins agent using declarative pipeline

HOWTO

• Configure agents  https://www.howtoforge.com/tutorial/ubuntu-jenkins-master-slave/
• Agent x node https://stackoverflow.com/questions/42050626/jenkins-pipeline-agent-vs-node
  
• Declarative pipeline syntax https://www.jenkins.io/doc/book/pipeline/syntax/
  
• Pipeline example https://www.jenkins.io/doc/pipeline/examples/
• https://www.jenkins.io/doc/book/pipeline/jenkinsfile/#using-multiple-agents

Configure Jenkins agent

agent

label 

  

   Execute the Pipeline, or stage, on an agent available in the Jenkins environment with the provided label. For example: agent { label 'my-defined-label' }

node

agent { node { label 'labelName' } } behaves the same as agent { label 'labelName' }, but node allows for additional options (such as customWorkspace).

Multiple agents

pipeline {
    agent none
    stages {
        stage('Build') {
            agent any
            steps {
                checkout scm
                sh 'make'
                stash includes: '**/target/*.jar', name: 'app'
            }
        }
        stage('Test on Linux') {
            agent { 
                label 'linux'
            }
            steps {
                unstash 'app'
                sh 'make check'
            }
            post {
                always {
                    junit '**/target/*.xml'
                }
            }
        }
        stage('Test on Windows') {
            agent {
                label 'windows'
            }
            steps {
                unstash 'app'
                bat 'make check'
            }
            post {
                always {
                    junit '**/target/*.xml'
                }
            }
        }
    }
}