Why Copying artifacts between jobs in Jenkins? - Purpose & Use Cases

The Big Idea

Discover how a simple step can save hours of manual work and prevent costly mistakes in your builds!

The Scenario

Imagine you have two separate Jenkins jobs: one builds your software, and the other runs tests. You need to move the build files from the first job to the second manually.

The Problem

Manually copying files between jobs is slow and risky. You might forget files, copy wrong versions, or waste time searching for the right artifacts. This causes delays and errors in your pipeline.

The Solution

Using artifact copying between jobs automates this transfer. Jenkins securely and reliably passes the exact files needed from one job to another without manual steps.

Before vs After

✗ Before

scp build/output.zip user@server:/test-job/input/
ssh user@server 'cd /test-job && ./run-tests.sh'

✓ After

copyArtifacts(projectName: 'BuildJob', filter: 'output.zip')
sh './run-tests.sh'

What It Enables

This lets your pipeline flow smoothly, saving time and avoiding mistakes by automatically sharing build results between jobs.

Real Life Example

When building a mobile app, the build job creates an APK file. The test job then automatically gets this APK to run tests, ensuring only the latest version is tested.

Key Takeaways

Manual file copying is slow and error-prone.

Copying artifacts automates file sharing between Jenkins jobs.

This improves pipeline speed and reliability.

Practice

1. What is the main purpose of using the copyArtifacts step in Jenkins?

easy

A. To compile source code in a Jenkins job

B. To delete artifacts after a build completes

C. To trigger a new Jenkins job automatically

D. To copy files from one Jenkins job to another

Solution

1. Step 1: Understand the copyArtifacts step

   The copyArtifacts step is designed to transfer files (artifacts) from one Jenkins job to another.

2. Step 2: Identify the main use case

   This step helps share build outputs between jobs without rebuilding, enabling reuse of files.

3. Final Answer:

   To copy files from one Jenkins job to another -> Option D

4. Quick Check:

   copyArtifacts = copy files between jobs [OK]

Hint: copyArtifacts copies files between jobs, not triggers or deletes [OK]

Common Mistakes:

• Confusing copyArtifacts with job triggers
• Thinking it deletes files instead of copying
• Assuming it compiles code

2. Which of the following is the correct syntax to copy artifacts from a job named BuildJob in a Jenkins pipeline script?

easy

A. copyArtifacts(projectName: 'BuildJob')

B. copyArtifacts('BuildJob')

C. copyArtifacts job: 'BuildJob'

D. copyArtifacts from: 'BuildJob'

Solution

1. Step 1: Recall the correct syntax for copyArtifacts

   The correct syntax uses named parameters, with projectName specifying the source job.

2. Step 2: Match the syntax to the options

   copyArtifacts(projectName: 'BuildJob') uses copyArtifacts(projectName: 'BuildJob'), which is the correct form in pipeline scripts.

3. Final Answer:

   copyArtifacts(projectName: 'BuildJob') -> Option A

4. Quick Check:

   Use named parameter projectName in copyArtifacts [OK]

Hint: Use named parameter projectName: 'JobName' in copyArtifacts [OK]

Common Mistakes:

• Using positional arguments instead of named parameters
• Using incorrect keywords like job or from
• Missing parentheses or quotes

3. Given the following Jenkins pipeline snippet, what files will be copied?

copyArtifacts(projectName: 'BuildJob', filter: '**/*.jar')

medium

A. Only files with .jar extension from BuildJob artifacts

B. All files from BuildJob workspace

C. Only files named exactly 'filter' from BuildJob

D. No files will be copied due to syntax error

Solution

1. Step 1: Understand the filter parameter

   The filter parameter uses Ant-style patterns to select files. '**/*.jar' means all .jar files in any folder.

2. Step 2: Determine which files are copied

   Only artifact files matching the pattern '*.jar' from the 'BuildJob' are copied, not all files.

3. Final Answer:

   Only files with .jar extension from BuildJob artifacts -> Option A

4. Quick Check:

   filter '**/*.jar' copies only .jar files [OK]

Hint: filter '**/*.ext' copies only files with that extension [OK]

Common Mistakes:

• Assuming all files copy without filter
• Thinking filter is a filename, not a pattern
• Believing syntax causes error here

4. You wrote this snippet to copy artifacts but it fails:

copyArtifacts(projectName: BuildJob)

What is the likely cause of the failure?

medium

A. copyArtifacts does not accept projectName parameter

B. Missing quotes around the job name 'BuildJob'

C. The job BuildJob does not exist

D. copyArtifacts requires a filter parameter

Solution

1. Step 1: Check syntax for projectName parameter

   In pipeline scripts, string values must be quoted. Missing quotes cause syntax errors.

2. Step 2: Identify the error cause

   Since BuildJob is unquoted, Jenkins treats it as a variable, causing failure if undefined.

3. Final Answer:

   Missing quotes around the job name 'BuildJob' -> Option B

4. Quick Check:

   Job names must be quoted strings [OK]

Hint: Always quote job names in copyArtifacts [OK]

Common Mistakes:

• Forgetting quotes around job names
• Assuming filter is mandatory
• Ignoring existence of source job

5. You want to copy only the latest successful build's output.zip artifact from job PackageJob to your current job. Which snippet correctly does this?

hard

A. copyArtifacts(projectName: 'PackageJob', selector: latest(), filter: 'output.zip')

B. copyArtifacts(projectName: 'PackageJob', filter: 'output.zip')

C. copyArtifacts(projectName: 'PackageJob', selector: lastSuccessful(), filter: 'output.zip')

D. copyArtifacts(projectName: 'PackageJob', selector: lastCompleted(), filter: 'output.zip')

Solution

1. Step 1: Understand selecting the build to copy from

   The selector parameter chooses which build's artifacts to copy. lastSuccessful() picks the latest successful build.

2. Step 2: Verify filter and selector usage

   copyArtifacts(projectName: 'PackageJob', selector: lastSuccessful(), filter: 'output.zip') uses selector: lastSuccessful() and filters for 'output.zip', matching the requirement exactly.

3. Final Answer:

   copyArtifacts(projectName: 'PackageJob', selector: lastSuccessful(), filter: 'output.zip') -> Option C

4. Quick Check:

   Use selector lastSuccessful() to copy latest successful build [OK]

Hint: Use selector lastSuccessful() to get latest successful build artifacts [OK]

Common Mistakes:

• Using selector latest() which is invalid
• Omitting selector and copying from last build regardless of status
• Using lastCompleted() which may include failed builds