Jenkins environment variables

Jenkins 환경 변수

List environment variables

Using env-vars.html

${JENKINS_HOST}/env-vars.html

Using shell command

pipeline {
    agent any

    stages {
        stage("Env Variables") {
            steps {
                sh "printenv" | sort
            }
        }
    }
}

Reading environment variables

pipeline {
    agent any

    stages {
        stage("Env Variables") {
            steps {
                echo "The build number is ${env.BUILD_NUMBER}"
                echo "You can also use \${BUILD_NUMBER} -> ${BUILD_NUMBER}"
                sh 'echo "I can access $BUILD_NUMBER in shell command as well."'
            }
        }
    }
}

Setting environment variables

pipeline {
    agent any

    environment {
        FOO = "bar"
    }

    stages {
        stage("Env Variables") {
            environment {
                NAME = "Alan"
            }

            steps {
                echo "FOO = ${env.FOO}"
                echo "NAME = ${env.NAME}"

                script {
                    env.TEST_VARIABLE = "some test value"
                }

                echo "TEST_VARIABLE = ${env.TEST_VARIABLE}"

                withEnv(["ANOTHER_ENV_VAR=here is some value"]) {
                    echo "ANOTHER_ENV_VAR = ${env.ANOTHER_ENV_VAR}"
                }
            }
        }
    }
}

Overriding environment variables

pipeline {
    agent any

    environment {
        FOO = "bar"
        NAME = "Joe"
    }

    stages {
        stage("Env Variables") {
            environment {
                NAME = "Alan" // overrides pipeline level NAME env variable
                BUILD_NUMBER = "2" // overrides the default BUILD_NUMBER
            }

            steps {
                echo "FOO = ${env.FOO}" // prints "FOO = bar"
                echo "NAME = ${env.NAME}" // prints "NAME = Alan"
                echo "BUILD_NUMBER =  ${env.BUILD_NUMBER}" // prints "BUILD_NUMBER = 2"

                script {
                    env.SOMETHING = "1" // creates env.SOMETHING variable
                }
            }
        }

        stage("Override Variables") {
            steps {
                script {
                    env.FOO = "IT DOES NOT WORK!" // it can't override env.FOO declared at the pipeline (or stage) level
                    env.SOMETHING = "2" // it can override env variable created imperatively
                }

                echo "FOO = ${env.FOO}" // prints "FOO = bar"
                echo "SOMETHING = ${env.SOMETHING}" // prints "SOMETHING = 2"

                withEnv(["FOO=foobar"]) { // it can override any env variable
                    echo "FOO = ${env.FOO}" // prints "FOO = foobar"
                }

                withEnv(["BUILD_NUMBER=1"]) {
                    echo "BUILD_NUMBER = ${env.BUILD_NUMBER}" // prints "BUILD_NUMBER = 1"
                }
            }
        }
    }
}

Storing Boolean values in environment variables

모든 변수는 String 으로 저장된다.

pipeline {
    agent any

    environment {
        IS_BOOLEAN = false
    }

    stages {
        stage("Env Variables") {
            steps {
                // one way
                script {
                    if (env.IS_BOOLEAN) {
                        echo "You can see this message, because \"false\" String evaluates to Boolean.TRUE value"
                    }

                    if (env.IS_BOOLEAN.toBoolean() == false) {
                        echo "You can see this message, because \"false\".toBoolean() returns Boolean.FALSE value"
                    }
                }

                // second way
                when {
                    expression {
                        env.IS_BOOLEAN.toBoolean() == true
                    }
                }

                // third way
                when {
                    environment name: "IS_BOOLEAN", value: "true" // syntax checking
                }
            }
        }
    }
}

Capturing the output from other steps

pipeline {
    agent any

    environment {
        LS = "${sh(script:'ls -lah', returnStdout: true).trim()}"
    }

    stages {
        stage("Env Variables") {
            steps {
                echo "LS = ${env.LS}"
            }
        }
    }
}

pipeline {
    agent any

    stages {
        stage("Env Variables") {
            steps {
                script {
                    env.LS = sh(script:'ls -lah', returnStdout: true).trim()
                    echo "LS = ${env.LS}"
                    // or if you access env variable in the shell command
                    sh 'echo $LS'
                }
            }
        }
    }
}

Dealing with null in the env variable

pipeline {
    agent any

    environment {
        SOME_VAL = "${someFunc() ?: ''}"
    }

    stages {
        stage("Env Variables") {
            steps {
                echo "Some value is ${env.SOME_VAL} of type class ${env.SOME_VAL?.class}"
            }
        }
    }
}

def someFunc() {
    return null
}

Reference

https://www.youtube.com/watch?v=KwQDxwZRZiE

https://e.printstacktrace.blog/jenkins-pipeline-environment-variables-the-definitive-guide/

https://github.com/wololock?tab=repositories&q=jenkin&type=&language=