How to Use Environment Variables in Jenkins Pipeline

In Jenkins pipelines, use the environment block to define environment variables accessible throughout the pipeline stages. These variables help store configuration values or secrets and can be referenced using env.VARIABLE_NAME in your pipeline script.

Syntax

The environment block is placed inside the pipeline or stage block. It defines key-value pairs where keys are variable names and values are their values. Variables set here are available as env.VARIABLE_NAME in the pipeline script.

Example parts:

• environment: block to declare variables
• VAR_NAME = 'value': sets a variable
• Access with env.VAR_NAME in steps

groovy

pipeline {
    agent any
    environment {
        GREETING = 'Hello'
        TARGET = 'World'
    }
    stages {
        stage('Example') {
            steps {
                echo "${env.GREETING}, ${env.TARGET}!"
            }
        }
    }
}

Example

This example shows a Jenkins pipeline that sets two environment variables GREETING and TARGET. The pipeline prints a message using these variables in the echo step.

groovy

pipeline {
    agent any
    environment {
        GREETING = 'Hello'
        TARGET = 'World'
    }
    stages {
        stage('Print Message') {
            steps {
                echo "${env.GREETING}, ${env.TARGET}!"
            }
        }
    }
}

Output

[Pipeline] echo
Hello, World!
[Pipeline] End of Pipeline

Common Pitfalls

Common mistakes when using environment variables in Jenkins pipelines include:

• Defining variables outside the environment block, so they are not recognized as environment variables.
• Trying to use variables without the env. prefix inside steps.
• Using single quotes in echo which prevents variable expansion.
• Overwriting environment variables unintentionally in nested scopes.

groovy

pipeline {
    agent any
    environment {
        NAME = 'Jenkins'
    }
    stages {
        stage('Wrong Usage') {
            steps {
                // This will print the literal string, not the variable value
                echo '$NAME'
                // Correct usage with double quotes and env prefix
                echo "${env.NAME}"
            }
        }
    }
}

Output

[Pipeline] echo
$NAME
[Pipeline] echo
Jenkins
[Pipeline] End of Pipeline

Quick Reference

Concept	Usage	Notes
Define environment variables	Use environment { VAR = 'value' }	Variables available as env.VAR
Access variable	Use echo "${env.VAR}"	Use double quotes for expansion
Scope	Defined in pipeline or stage	Stage-level overrides pipeline-level
Secrets	Use Jenkins credentials with credentials()	Avoid plain text in environment
Common mistake	Using single quotes in echo	Variables won't expand

Key Takeaways

Use the environment block to define variables accessible in all pipeline stages.

Access environment variables with env.VARIABLE_NAME inside pipeline steps.

Always use double quotes in echo to expand variables correctly.

Define environment variables at the pipeline or stage level depending on scope needs.

Avoid putting secrets directly in environment; use Jenkins credentials instead.