currentBuild variables in Jenkins - Mini Project: Build & Apply

Using currentBuild Variables in Jenkins Pipeline

📖 Scenario: You are working on a Jenkins pipeline to automate your software build process. You want to track and display information about the current build, such as its number and result status, to help your team monitor the build progress easily.

🎯 Goal: Build a simple Jenkins pipeline script that uses currentBuild variables to access and display the build number and build result.

📋 What You'll Learn

Create a variable to store the current build number using currentBuild.number

Create a variable to store the current build result using currentBuild.result

Print both the build number and build result in the pipeline script

💡 Why This Matters

🌍 Real World

Jenkins pipelines often need to report build status and details to users or other systems for monitoring and alerting.

💼 Career

Knowing how to use <code>currentBuild</code> variables is essential for DevOps engineers to create informative and responsive CI/CD pipelines.

1

Create a variable for the current build number

Create a variable called buildNumber and set it to currentBuild.number to get the current build number.

Jenkins

# Your code here

Hint

The currentBuild.number gives you the number of the current build in Jenkins.

2

Create a variable for the current build result

Create a variable called buildResult and set it to currentBuild.result to get the current build result status.

Jenkins

def buildNumber = currentBuild.number
# Your code here

Hint

The currentBuild.result holds the status of the build like SUCCESS, FAILURE, or null if not finished.

3

Use the variables in a print statement

Write a println statement that prints the text: "Build number: " followed by buildNumber and " with result: " followed by buildResult.

Jenkins

def buildNumber = currentBuild.number
def buildResult = currentBuild.result
# Your code here

Hint

Use Groovy string interpolation with ${variable} inside double quotes to print variables.

4

Display the build information

Run the pipeline script and ensure the output shows the build number and build result in the format: Build number: X with result: Y where X is the build number and Y is the build result.

Jenkins

def buildNumber = currentBuild.number
def buildResult = currentBuild.result
println("Build number: ${buildNumber} with result: ${buildResult}")
# Run the script to see output

Hint

The first build usually has number 1 and result is null before completion.

Practice

1. What does the currentBuild.number variable represent in a Jenkins Pipeline?

easy

A. The number of failed tests in the build

B. The unique build number of the current running job

C. The number of parallel stages in the pipeline

D. The total number of builds ever run on Jenkins

Solution

1. Step 1: Understand the role of currentBuild

   The currentBuild variable holds information about the current Jenkins job execution.

2. Step 2: Identify what number means

   The number property specifically gives the unique build number assigned to this run.

3. Final Answer:

   The unique build number of the current running job -> Option B

4. Quick Check:

   currentBuild.number = build number [OK]

Hint: Remember: currentBuild.number is the build's unique ID [OK]

Common Mistakes:

• Confusing build number with total builds
• Thinking it counts test failures
• Mixing it with stage counts

2. Which of the following is the correct way to access the current build's result status in a Jenkins Pipeline script?

easy

A. currentBuild.result

B. currentBuild.status

C. currentBuild.state

D. currentBuild.outcome

Solution

1. Step 1: Recall the property for build result

   The Jenkins currentBuild object uses result to store the build status like SUCCESS or FAILURE.

2. Step 2: Verify other options

   status, state, and outcome are not valid properties for currentBuild.

3. Final Answer:

   currentBuild.result -> Option A

4. Quick Check:

   Build status = currentBuild.result [OK]

Hint: Use currentBuild.result for build status, not status or state [OK]

Common Mistakes:

• Using currentBuild.status which is undefined
• Confusing result with outcome
• Trying to access non-existent properties

3. Given this Jenkins Pipeline snippet:

echo "Build number: ${currentBuild.number}"
echo "Build status: ${currentBuild.result}"

If the build number is 42 and the build just finished successfully, what will be the output?

medium

A. Build number: 42
Build status: SUCCESS

B. Build number: 42
Build status: null

C. Build number: null
Build status: SUCCESS

D. Build number: 0
Build status: FAILURE

Solution

1. Step 1: Understand variable values after build

   After a successful build, currentBuild.number is the build number (42), and currentBuild.result is "SUCCESS".

2. Step 2: Substitute variables in echo statements

   Replacing variables gives:
   Build number: 42
   Build status: SUCCESS

3. Final Answer:

   Build number: 42 Build status: SUCCESS -> Option A

4. Quick Check:

   Number=42, Result=SUCCESS [OK]

Hint: After success, currentBuild.result = SUCCESS, number = build ID [OK]

Common Mistakes:

• Expecting result to be null before build ends
• Confusing build number with zero
• Assuming result is FAILURE by default

4. You wrote this Jenkins Pipeline snippet:

if (currentBuild.status == 'SUCCESS') {
  echo 'Build succeeded'
} else {
  echo 'Build failed'
}

But it always prints 'Build failed' even when the build succeeds. What is the issue?

medium

A. The string comparison should use == instead of =

B. The if statement needs parentheses around the condition

C. The echo command is incorrect syntax

D. The property should be currentBuild.result, not currentBuild.status

Solution

1. Step 1: Identify the incorrect property usage

   The currentBuild object does not have a status property; the correct property for build result is result.

2. Step 2: Understand why the condition fails

   Since currentBuild.status is undefined, the condition never matches 'SUCCESS', so it always goes to else.

3. Final Answer:

   The property should be currentBuild.result, not currentBuild.status -> Option D

4. Quick Check:

   Use currentBuild.result for status check [OK]

Hint: Use currentBuild.result, not currentBuild.status, for build status [OK]

Common Mistakes:

• Using currentBuild.status instead of currentBuild.result
• Confusing assignment (=) with comparison (==)
• Incorrect echo syntax in Jenkinsfile

5. In a Jenkins Pipeline, you want to set the display name of the current build to include the build number and status, like "Build #42 - SUCCESS". Which snippet correctly does this?

hard

A. currentBuild.displayName = "Build #${build.number} - ${build.result}"

B. currentBuild.name = "Build #${currentBuild.number} - ${currentBuild.status}"

C. currentBuild.displayName = "Build #${currentBuild.number} - ${currentBuild.result}"

D. currentBuild.setDisplayName("Build #${currentBuild.number} - ${currentBuild.result}")

Solution

1. Step 1: Identify the correct property to set display name

   The property to set the build's display name is currentBuild.displayName.

2. Step 2: Use correct variable names and syntax

   Use currentBuild.number and currentBuild.result inside the string with Groovy string interpolation.

3. Final Answer:

   currentBuild.displayName = "Build #${currentBuild.number} - ${currentBuild.result}" -> Option C

4. Quick Check:

   Set displayName with currentBuild.displayName and correct variables [OK]

Hint: Set displayName with currentBuild.displayName and correct variables [OK]

Common Mistakes:

• Using currentBuild.name instead of displayName
• Using undefined variable 'build'
• Trying to call setDisplayName() which doesn't exist