Build tools (Maven, Gradle, npm) in Jenkins - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to run a Maven build in a Jenkins pipeline.

Jenkins

pipeline {
  agent any
  stages {
    stage('Build') {
      steps {
        sh 'mvn [1]'
      }
    }
  }
}

Drag options to blanks, or click blank then click option'

Acompile

Btest

Cclean install

Dpackage

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'clean install' when only compilation is needed.

Using 'test' which runs tests but does not compile separately.

The compile goal compiles the source code of the project. It is a common first step in Maven builds.

2fill in blank

medium

Complete the code to run a Gradle build task in a Jenkins pipeline.

Jenkins

pipeline {
  agent any
  stages {
    stage('Build') {
      steps {
        sh './gradlew [1]'
      }
    }
  }
}

Drag options to blanks, or click blank then click option'

Aassemble

Bbuild

Cclean

Dtest

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'assemble' which only packages without running tests.

Using 'clean' which deletes build files but does not build.

The build task compiles, tests, and assembles the project in Gradle.

3fill in blank

hard

Fix the error in the npm build command in this Jenkins pipeline.

Jenkins

pipeline {
  agent any
  stages {
    stage('Build') {
      steps {
        sh 'npm [1]'
      }
    }
  }
}

Drag options to blanks, or click blank then click option'

Abuild

Binstall

Crun build

Dstart

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'npm build' which is not a valid npm command.

Using 'npm start' which runs the start script, not build.

To run a custom npm script like 'build', you use npm run build. Just 'npm build' is not a valid command.

4fill in blank

hard

Fill both blanks to run a Maven clean and package in a Jenkins pipeline.

Jenkins

pipeline {
  agent any
  stages {
    stage('Build') {
      steps {
        sh 'mvn [1] [2]'
      }
    }
  }
}

Drag options to blanks, or click blank then click option'

Aclean

Binstall

Cpackage

Dtest

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'install' instead of 'package' which also installs to local repo.

Using 'test' which only runs tests.

The clean goal removes previous build files, and package compiles and packages the project.

5fill in blank

hard

Fill all three blanks to run a Gradle clean, build, and test in a Jenkins pipeline.

Jenkins

pipeline {
  agent any
  stages {
    stage('Build and Test') {
      steps {
        sh './gradlew [1] [2] [3]'
      }
    }
  }
}

Drag options to blanks, or click blank then click option'

Aclean

Bbuild

Ctest

Dassemble

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'assemble' instead of 'build' which does not run tests.

Omitting 'clean' which may cause stale files.

The commands clean, build, and test run cleaning, building, and testing respectively in Gradle.

Practice

1. What is the primary purpose of build tools like Maven, Gradle, and npm in Jenkins pipelines?

easy

A. To automate compiling, testing, and packaging code

B. To write application code manually

C. To deploy applications to production servers

D. To monitor server health and uptime

Solution

1. Step 1: Understand build tools' role

   Build tools automate tasks like compiling code, running tests, and packaging software.

2. Step 2: Connect with Jenkins pipeline usage

   Jenkins pipelines use these tools to automate software delivery steps efficiently.

3. Final Answer:

   To automate compiling, testing, and packaging code -> Option A

4. Quick Check:

   Build tools automate build tasks = D [OK]

Hint: Build tools automate code build and test steps [OK]

Common Mistakes:

• Confusing build tools with deployment tools
• Thinking build tools write code
• Mixing monitoring tools with build tools

2. Which of the following is the correct Jenkins pipeline syntax to run a Maven build command?

easy

A. sh 'gradle build'

B. bat 'npm install'

C. bat 'mvn deploy'

D. sh 'mvn clean install'

Solution

1. Step 1: Identify the shell command for Maven

   Maven commands run in shell using sh 'mvn ...' in Jenkins on Linux agents.

2. Step 2: Match the correct Maven build command

   mvn clean install compiles and packages the project.

3. Final Answer:

   sh 'mvn clean install' -> Option D

4. Quick Check:

   Maven build command in shell = C [OK]

Hint: Use sh 'mvn clean install' for Maven builds on Linux [OK]

Common Mistakes:

• Using npm or gradle commands for Maven builds
• Using bat instead of sh on Linux agents
• Confusing deploy with build commands

3. Given this Jenkins pipeline snippet, what will be the output if the npm install command fails?

pipeline {
  agent any
  stages {
    stage('Install') {
      steps {
        sh 'npm install'
      }
    }
  }
}

medium

A. Pipeline continues to next stage ignoring failure

B. Pipeline stops and marks build as failed

C. Pipeline retries npm install automatically

D. Pipeline marks build as unstable but continues

Solution

1. Step 1: Understand default Jenkins shell step behavior

   By default, if sh command fails, Jenkins stops the pipeline and marks build as failed.

2. Step 2: Apply this to npm install failure

   If npm install fails, the pipeline will stop immediately and fail.

3. Final Answer:

   Pipeline stops and marks build as failed -> Option B

4. Quick Check:

   Failed shell command stops pipeline = A [OK]

Hint: Failed shell commands stop Jenkins pipeline by default [OK]

Common Mistakes:

• Assuming pipeline continues after failure
• Thinking Jenkins retries commands automatically
• Confusing unstable with failed build status

4. You wrote this Jenkins pipeline step to run Gradle build but it fails with 'command not found':

sh 'gradle build'

What is the most likely cause and fix?

medium

A. Gradle is not installed or not in PATH; install Gradle or set PATH

B. Syntax error in Jenkinsfile; change to bat 'gradle build'

C. Use npm instead of Gradle for Java projects

D. Replace 'build' with 'install' in the command

Solution

1. Step 1: Analyze error 'command not found'

   This error means the system cannot find the gradle command in the PATH.

2. Step 2: Fix by installing Gradle or updating PATH

   Ensure Gradle is installed on the Jenkins agent and its bin directory is in the PATH environment variable.

3. Final Answer:

   Gradle is not installed or not in PATH; install Gradle or set PATH -> Option A

4. Quick Check:

   Command not found means missing install or PATH = A [OK]

Hint: Check PATH and install Gradle if 'command not found' error occurs [OK]

Common Mistakes:

• Using Windows bat syntax on Linux agents
• Confusing npm with Gradle for Java builds
• Changing command without fixing environment

5. You want to create a Jenkins pipeline that runs npm install, then runs tests with npm test, but only if install succeeds. Which pipeline snippet correctly implements this?

hard

A. sh 'npm install; npm test'

B. try {
sh 'npm install'
sh 'npm test'
} catch (e) {
echo 'Install failed'
}

C. sh 'npm install && npm test'

D. sh 'npm test'
sh 'npm install'

Solution

1. Step 1: Understand command chaining with &&

   Using npm install && npm test runs tests only if install succeeds.

2. Step 2: Compare with other options

   sh 'npm install; npm test' runs test regardless because ';' executes the next command irrespective of exit code. try { sh 'npm install' sh 'npm test' } catch (e) { echo 'Install failed' } uses try-catch but Jenkins declarative pipeline syntax does not support this directly. sh 'npm test' sh 'npm install' runs test before install, which is wrong order.

3. Final Answer:

   sh 'npm install && npm test' -> Option C

4. Quick Check:

   Use && to run second command only if first succeeds = B [OK]

Hint: Chain commands with && to run second only if first succeeds [OK]

Common Mistakes:

• Using ';' instead of '&&' to chain commands
• Using try-catch incorrectly in Jenkinsfile
• Running tests before installing dependencies