jenkinsfile

pipeline {
  agent
    node {
      label 'generic'
         }
  options {
    buildDiscarder(logRotator(numToKeepStr: '5'))
  }
  environment
    {
        VERSION   = 'latest'
        PROJECT   = 'shelleg/gitbook'
        IMAGE     = "${PROJECT}/${VERSION}:latest"
    }
  stages {
    stage('Build preparations')
        {
            steps
            {
                script
                {
                    // calculate GIT lastest commit short-hash
                    gitCommitHash = sh(returnStdout: true, script: 'git rev-parse HEAD').trim()
                    shortCommitHash = gitCommitHash.take(7)
                    // calculate a sample version tag
                    VERSION = shortCommitHash
                    // set the build display name
                    currentBuild.displayName = "#${BUILD_ID}-${VERSION}"
                    IMAGE = "$PROJECT:$VERSION"
                    IMAGE_LATEST = "$PROJECT:latest"
                }
            }
        }
    stage('Build') {
      steps {
        docker.build("$IMAGE")
        docker.build("$IMAGE_LATEST")
      }
    }
    stage('Publish') {
      when {
        branch 'master'
      }
      steps {
        withDockerRegistry([ credentialsId: "dockerHub", url: "" ]) {
        // version eq latest git tag
        docker.image(IMAGE).push()
        // override the latest tag
        docker.image(IMAGE_LATEST).push()
        }
      }
    }
  }
}