How to Set Environment Variables in Jenkins Pipeline

In Jenkins Pipeline, you set environment variables using the environment block in declarative pipelines or by using env.VAR_NAME = 'value' in scripted pipelines. These variables are then accessible throughout the pipeline stages and steps.

Syntax

In Jenkins declarative pipelines, environment variables are set inside the environment block at the top level or inside stages. In scripted pipelines, you assign variables directly to env object.

• Declarative: Use environment { VAR_NAME = 'value' }
• Scripted: Use env.VAR_NAME = 'value'

groovy

pipeline {
    agent any
    environment {
        MY_VAR = 'HelloWorld'
    }
    stages {
        stage('Example') {
            steps {
                echo "Value is: ${env.MY_VAR}"
            }
        }
    }
}

Example

This example shows a declarative Jenkins pipeline setting an environment variable GREETING and printing it in a stage.

groovy

pipeline {
    agent any
    environment {
        GREETING = 'Hello from Jenkins'
    }
    stages {
        stage('Print Greeting') {
            steps {
                echo "Message: ${env.GREETING}"
            }
        }
    }
}

Output

[Pipeline] echo
Message: Hello from Jenkins

Common Pitfalls

Common mistakes when setting environment variables in Jenkins pipelines include:

• Trying to set variables inside steps block in declarative pipelines instead of environment.
• Using shell syntax like export VAR=value which only affects the shell, not the Jenkins environment.
• Not referencing variables with ${env.VAR_NAME} or env.VAR_NAME in Groovy.

groovy

pipeline {
    agent any
    stages {
        stage('Wrong') {
            steps {
                // This does NOT set a Jenkins env variable
                sh 'export BAD_VAR=wrong'
                echo "Bad var: ${env.BAD_VAR}"
            }
        }
        stage('Right') {
            environment {
                GOOD_VAR = 'right'
            }
            steps {
                echo "Good var: ${env.GOOD_VAR}"
            }
        }
    }
}

Output

[Pipeline] sh
+ export BAD_VAR=wrong
[Pipeline] echo
Bad var: 
[Pipeline] echo
Good var: right

Quick Reference

Summary tips for setting environment variables in Jenkins Pipeline:

• Use environment block in declarative pipelines.
• Use env.VAR_NAME = 'value' in scripted pipelines.
• Access variables with ${env.VAR_NAME} or env.VAR_NAME.
• Shell export commands do not persist variables in Jenkins environment.

Key Takeaways

Set environment variables in declarative pipelines using the environment block.

In scripted pipelines, assign variables directly to the env object.

Access environment variables with ${env.VAR_NAME} syntax.

Avoid using shell export commands to set Jenkins environment variables.

Environment variables set in the pipeline are available in all stages and steps.