Artifact fingerprinting in Jenkins - Mini Project: Build & Apply

Artifact Fingerprinting in Jenkins

📖 Scenario: You are working as a DevOps engineer managing a Jenkins pipeline for a software project. You want to track and verify the artifacts produced by your builds to ensure consistency and traceability.Artifact fingerprinting helps Jenkins record unique identifiers (hashes) for files created during builds. This way, you can trace which build produced which artifact and detect if artifacts are reused or changed.

🎯 Goal: Build a simple Jenkins pipeline script that enables artifact fingerprinting for a specific file. You will create a file, configure fingerprinting, and then print the fingerprint information.

📋 What You'll Learn

Create a file named app.jar with sample content

Enable fingerprinting for the app.jar artifact

Use Jenkins pipeline syntax to record the fingerprint

Print the fingerprint details in the build log

💡 Why This Matters

🌍 Real World

Artifact fingerprinting is used in real Jenkins pipelines to track build outputs and ensure traceability of files across builds and deployments.

💼 Career

Understanding artifact fingerprinting helps DevOps engineers maintain build integrity and troubleshoot issues related to artifact reuse or corruption.

1

Create the artifact file

Create a file named app.jar with the exact content Sample artifact content using the sh step in the Jenkins pipeline.

Jenkins

// Your code here to create app.jar with content

Hint

Use the sh step with an echo command to create the file app.jar with the exact text.

2

Enable artifact fingerprinting

Add a fingerprint step inside the Create Artifact stage to fingerprint the file app.jar.

Jenkins

pipeline {
    agent any
    stages {
        stage('Create Artifact') {
            steps {
                sh 'echo "Sample artifact content" > app.jar'
                // Add fingerprint step for app.jar below
            }
        }
    }
}

Hint

Use the fingerprint step with the exact string 'app.jar' to enable fingerprinting.

3

Retrieve fingerprint information

Add a script block inside the Create Artifact stage steps to get the fingerprint information for app.jar using currentBuild.rawBuild.getFingerprint('app.jar') and store it in a variable called fp.

Jenkins

pipeline {
    agent any
    stages {
        stage('Create Artifact') {
            steps {
                sh 'echo "Sample artifact content" > app.jar'
                fingerprint 'app.jar'
                script {
                    // Get fingerprint info for app.jar and assign to fp
                }
            }
        }
    }
}

Hint

Use a script block and assign currentBuild.rawBuild.getFingerprint('app.jar') to a variable named fp.

4

Print fingerprint details

Inside the same script block, add a println statement to print the fingerprint hash using fp.getHashString().

Jenkins

pipeline {
    agent any
    stages {
        stage('Create Artifact') {
            steps {
                sh 'echo "Sample artifact content" > app.jar'
                fingerprint 'app.jar'
                script {
                    def fp = currentBuild.rawBuild.getFingerprint('app.jar')
                    // Print the fingerprint hash below
                }
            }
        }
    }
}

Hint

Use println with the exact string Fingerprint hash: ${fp.getHashString()} to display the fingerprint.

Practice

1. What is the main purpose of artifact fingerprinting in Jenkins?

easy

A. To uniquely track files across different builds

B. To speed up the build process

C. To automatically deploy artifacts to servers

D. To create backups of build logs

Solution

1. Step 1: Understand artifact fingerprinting concept

   Artifact fingerprinting is used to track files uniquely across Jenkins builds.

2. Step 2: Identify the main purpose

   Its main purpose is to know where files come from and where they are used, not speeding builds or deployment.

3. Final Answer:

   To uniquely track files across different builds -> Option A

4. Quick Check:

   Artifact fingerprinting = Unique file tracking [OK]

Hint: Fingerprinting tracks files uniquely across builds [OK]

Common Mistakes:

• Confusing fingerprinting with deployment
• Thinking it speeds up builds
• Assuming it backs up logs

2. Which Jenkins pipeline step is used to enable artifact fingerprinting for a file?

easy

A. archiveArtifacts 'file.txt'

B. publish 'file.txt'

C. stash 'file.txt'

D. fingerprint 'file.txt'

Solution

1. Step 1: Recall Jenkins pipeline steps for artifacts

   Common steps include archiveArtifacts, stash, fingerprint, and publish.

2. Step 2: Identify the step for fingerprinting

   The fingerprint step is specifically used to enable artifact fingerprinting on files.

3. Final Answer:

   fingerprint 'file.txt' -> Option D

4. Quick Check:

   Use fingerprint step to track files [OK]

Hint: Use fingerprint step with file path to track [OK]

Common Mistakes:

• Using archiveArtifacts instead of fingerprint
• Confusing stash with fingerprint
• Using publish which is unrelated

3. Given this Jenkins pipeline snippet:

pipeline {
  agent any
  stages {
    stage('Build') {
      steps {
        sh 'echo Hello > output.txt'
        fingerprint 'output.txt'
      }
    }
  }
}

What does the fingerprint 'output.txt' step do here?

medium

A. Deletes output.txt after the build

B. Creates a unique hash for output.txt to track it across builds

C. Copies output.txt to the workspace

D. Uploads output.txt to a remote server

Solution

1. Step 1: Analyze the pipeline snippet

   The pipeline creates a file output.txt and then fingerprints it.

2. Step 2: Understand fingerprint step effect

   The fingerprint step creates a unique hash for the file to track it across builds, not deleting or copying it.

3. Final Answer:

   Creates a unique hash for output.txt to track it across builds -> Option B

4. Quick Check:

   Fingerprint = unique hash tracking [OK]

Hint: Fingerprint creates unique hash for file tracking [OK]

Common Mistakes:

• Thinking fingerprint deletes files
• Assuming it copies files
• Confusing fingerprint with upload

4. You added fingerprint 'app.jar' in your Jenkins pipeline, but fingerprints are not generated. What is a likely cause?

medium

A. You must archive artifacts before fingerprinting

B. Fingerprinting requires a separate plugin installation

C. The file path 'app.jar' is incorrect or file does not exist

D. Fingerprinting only works on text files

Solution

1. Step 1: Check file existence for fingerprinting

   Fingerprinting requires the file to exist at the specified path during the build.

2. Step 2: Identify common causes for no fingerprints

   If the file path is wrong or file missing, fingerprinting won't generate fingerprints.

3. Final Answer:

   The file path 'app.jar' is incorrect or file does not exist -> Option C

4. Quick Check:

   File must exist for fingerprinting [OK]

Hint: Ensure file exists at path before fingerprinting [OK]

Common Mistakes:

• Assuming fingerprint needs extra plugin
• Thinking archiveArtifacts is mandatory before fingerprint
• Believing fingerprint only works on text files

5. In a Jenkins pipeline, you want to track multiple artifacts and find all builds that used them. Which approach correctly uses artifact fingerprinting for this?

hard

A. Use fingerprint '**/*.jar' after building all jar files

B. Archive artifacts first, then fingerprint only one file manually

C. Use stash for all files and fingerprint none

D. Fingerprint files only in the first build, skip others

Solution

1. Step 1: Understand tracking multiple artifacts

   To track multiple files, fingerprinting should be applied to all relevant files, e.g., using a pattern.

2. Step 2: Evaluate options for multiple files

   Using fingerprint '**/*.jar' fingerprints all jar files, enabling tracking across builds.

3. Final Answer:

   Use fingerprint '**/*.jar' after building all jar files -> Option A

4. Quick Check:

   Fingerprint all files with pattern for tracking [OK]

Hint: Fingerprint all files with a pattern to track multiple artifacts [OK]

Common Mistakes:

• Fingerprinting only one file when multiple exist
• Confusing stash with fingerprinting
• Skipping fingerprinting in later builds