How to Use Stash and Unstash in Jenkins Pipeline

In Jenkins pipelines, use stash to save files temporarily and unstash to retrieve them in another stage. This helps share files between stages without writing to permanent storage.

Syntax

The stash command saves files with a name for later use, and unstash retrieves those files by name in another stage.

stash syntax:

stash name: 'stashName', includes: 'filesPattern'

unstash syntax:

unstash 'stashName'

Here, name is the identifier for the stash, and includes specifies which files to save.

groovy

stash name: 'myFiles', includes: '**/*.txt'
unstash 'myFiles'

Example

This example shows how to stash a file in one stage and unstash it in a later stage to use it.

groovy

pipeline {
    agent any
    stages {
        stage('Create File') {
            steps {
                sh 'echo Hello Jenkins > greeting.txt'
                stash name: 'greetingFiles', includes: 'greeting.txt'
            }
        }
        stage('Use File') {
            steps {
                unstash 'greetingFiles'
                sh 'cat greeting.txt'
            }
        }
    }
}

Output

Hello Jenkins

Common Pitfalls

• Forgetting to unstash the files before using them causes errors because the files are not present.
• Using the same stash name in multiple places without clearing can overwrite files unexpectedly.
• stash only works within the same pipeline run; it cannot share files across different runs.
• Including too many files in stash can slow down the pipeline due to large data transfer.

groovy

pipeline {
    agent any
    stages {
        stage('Wrong Usage') {
            steps {
                // Trying to use file without unstashing
                sh 'cat greeting.txt' // This will fail if file is not present
            }
        }
        stage('Correct Usage') {
            steps {
                unstash 'greetingFiles'
                sh 'cat greeting.txt' // This works
            }
        }
    }
}

Quick Reference

Command	Purpose	Example
stash	Save files temporarily in pipeline	stash name: 'data', includes: '**/*.log'
unstash	Retrieve stashed files in another stage	unstash 'data'

Key Takeaways

Use stash to save files and unstash to retrieve them between pipeline stages.

Always unstash files before accessing them to avoid errors.

Stash names must be unique per pipeline run to prevent overwriting.

Stash and unstash only share files within the same pipeline execution.

Keep stashed files minimal to maintain pipeline speed.