Chapter 21: Jenkins Pipeline and Jenkinsfile

21.5 Full Declarative Jenkinsfile for badge Node

By Ravindra Bagale · Last updated: 25 October 2026

Why: the problem

Now we write the full Jenkinsfile for the badge Node app. Think of Myntra before a big sale. Every change to the shop app must pass the same checks, in the same order, every time. Checkout the code. Install. Build. Test. Copy the result to a place where people can try it. Keep the build output safe. Tell the team if it broke. If a human does this by hand, one step gets skipped on a busy day. A full Jenkinsfile never skips. It also stops at the first red stage, so a broken build never reaches the live folder. In this lesson you will build the file in three rounds. First the simple stages. Then options and environment. Then post actions, archive and test reports. Each round runs green before the next.

What we will build

You will write the complete badge Node Jenkinsfile with Checkout, Install, Build, Test and Lab Live stages. You will add timestamps, a timeout, an environment block, JUnit test reports, archived artifacts and post messages. You will run it green, break a test, and see the Live stage skipped.

What: every term in plain English

• checkout scm — Clones the exact commit this build is for.
• options — Settings for the whole pipeline, like timeout and timestamps.
• environment — Variables for every stage.
• archiveArtifacts — Saves files on the build page for download.
• junit — Reads test result XML and shows a test trend chart.
• post — Actions after the stages: always, success, failure, unstable, cleanup.
• Lab Live — A folder on the agent that acts as our practice live server.
• Skipped stage — A stage that did not run because an earlier one failed.

How: step by step

1. Add a JUnit reporter

   npm install --save-dev jest-junit
   

   What it does: Lets Jest write test results as XML.

   Output

   added 6 packages in 2s
   

2. Tell Jest to write XML

   npm pkg set scripts.test="jest --ci --reporters=default --reporters=jest-junit"
   

   What it does: Writes junit.xml on every test run.

   Output

   (no output)
   

3. Write the Jenkinsfile

   nano Jenkinsfile
   

   What it does: Full file from example 2 below.

   Output

   (file saved)
   

4. Push

   git add . && git commit -m "ci: full pipeline" && git push
   

   What it does: Jenkins sees the new file.

   Output

   [main 7d3e2a1] ci: full pipeline
   

5. Run

   Build Now
   

   What it does: All five stages run.

   Output

   Finished: SUCCESS
   

6. Open the reports

   Build page > Test Result and Build Artifacts
   

   What it does: Shows 2 tests passed and dist/index.html.

   Output

   Test Result (no failures)
   dist/index.html 31 B
   

7. Break and watch

   Change one expect, push, build
   

   What it does: Test is red, Live is skipped.

   Output

   Stage "Live" skipped due to earlier failure(s)
   

Example 1: Round 1: the five stages

Stack. Jenkins Declarative, Node.js 20

Goal. Round 1: the five stages.

Jenkinsfile

pipeline {
  agent any
  stages {
    stage('Checkout') { steps { checkout scm } }
    stage('Install')  { steps { sh 'npm ci' } }
    stage('Build')    { steps { sh 'npm run build' } }
    stage('Test')     { steps { sh 'npm test' } }
    stage('Live') {
      steps {
        sh 'mkdir -p "$HOME/lab-live/badge-node"'
        sh 'cp -r dist/* "$HOME/lab-live/badge-node/"'
        sh 'ls -l "$HOME/lab-live/badge-node"'
      }
    }
  }
}

What each line does

• checkout scm — Clones the commit. Declarative does this anyway; writing it makes it visible.
• mkdir -p — Makes the live folder if missing, no error if it exists.
• "$HOME/..." — Single quotes in Groovy, so the shell expands HOME, not Groovy.
• cp -r dist/* — Copies the build to the lab live folder.

Green output

[Pipeline] stage (Checkout)
[Pipeline] stage (Install)
added 276 packages in 8s
[Pipeline] stage (Build)
build done: dist/index.html
[Pipeline] stage (Test)
Tests: 2 passed, 2 total
[Pipeline] stage (Live)
+ ls -l /var/jenkins_home/lab-live/badge-node
-rw-r--r-- 1 jenkins jenkins 31 Oct 25 10:30 index.html
Finished: SUCCESS

Expected result. Five green boxes. The live folder has the new file.

Example 2: Round 2 and 3: the full file

Stack. Jenkins, Jest, jest-junit, Workspace Cleanup plugin

Goal. Round 2 and 3: the full file.

Jenkinsfile

pipeline {
  agent any
  options {
    timestamps()
    timeout(time: 15, unit: 'MINUTES')
    buildDiscarder(logRotator(numToKeepStr: '20'))
    disableConcurrentBuilds()
  }
  environment {
    APP = 'badge-node'
    LIVE_DIR = "${env.HOME}/lab-live/badge-node"
    CI = 'true'
  }
  stages {
    stage('Checkout') { steps { checkout scm } }
    stage('Install')  { steps { sh 'node --version && npm ci' } }
    stage('Build')    { steps { sh 'npm run build' } }
    stage('Test') {
      steps { sh 'npm test' }
      post { always { junit 'junit.xml' } }
    }
    stage('Live') {
      steps {
        sh 'mkdir -p "$LIVE_DIR" && cp -r dist/* "$LIVE_DIR/"'
        echo "Lab live updated for ${APP} build ${BUILD_NUMBER}"
      }
    }
  }
  post {
    success { archiveArtifacts artifacts: 'dist/**', fingerprint: true }
    failure { echo "FAILED: ${APP} #${BUILD_NUMBER} see ${BUILD_URL}console" }
    always  { echo "Result: ${currentBuild.currentResult} in ${currentBuild.durationString}" }
    cleanup { cleanWs() }
  }
}

What each line does

• timestamps() — Time on every log line.
• timeout(time: 15, unit: 'MINUTES') — Kills a stuck build after 15 minutes.
• buildDiscarder — Keeps only the last 20 builds, saves disk.
• disableConcurrentBuilds() — One build of this job at a time.
• environment APP, LIVE_DIR, CI — Variables for all stages. CI=true makes tools act non interactive.
• junit 'junit.xml' — Shows test results, inside a stage post always so it runs even when tests fail.
• fingerprint: true — Tracks this file across jobs.
• cleanup { cleanWs() } — Deletes the workspace at the very end. Needs the Workspace Cleanup plugin.

Green output

10:41:02  [Pipeline] stage (Install)
10:41:02  + node --version
10:41:02  v20.15.1
10:41:10  added 276 packages in 8s
10:41:11  [Pipeline] stage (Test)
10:41:14  Tests: 2 passed, 2 total
10:41:14  Recording test results
10:41:15  [Pipeline] stage (Live)
10:41:15  Lab live updated for badge-node build 5
10:41:15  Archiving artifacts
10:41:15  Result: SUCCESS in 14 sec
10:41:16  [WS-CLEANUP] Deleting project workspace...
Finished: SUCCESS

Expected result. A real company shape: time limits, history limits, test reports, artifacts and clean workspace.

Example 3: Break a test and read the red build

Stack. Jenkins Declarative

Goal. Break a test and read the red build.

terminal

sed -i 's/passing/oops/' test/badge.test.js
git commit -am "test: break on purpose"
git push

What each line does

• sed -i — Makes one test fail.
• git commit -am — Commits changed tracked files.
• Live skipped — Declarative skips later stages after a failure.
• junit still runs — Because it is in post always of the Test stage.

Green output

[Pipeline] stage (Test)
FAIL test/badge.test.js
  x makes a badge
Tests: 1 failed, 1 passed, 2 total
script returned exit code 1
Recording test results
[Pipeline] stage (Live)
Stage "Live" skipped due to earlier failure(s)
FAILED: badge-node #6 see http://localhost:8080/job/badge-scm/6/console
Result: FAILURE in 9.2 sec
Finished: FAILURE

Expected result. The broken code never reached the live folder. The test chart shows one failure. Revert with git revert HEAD.

Verify: did it work?

1. Check the live folder

   docker exec jenkins ls -l /var/jenkins_home/lab-live/badge-node
   

   What it does: Only green builds update it.

   Output

   index.html
   

2. Test trend

   Job page > Test Result Trend
   

   What it does: A chart of pass and fail over builds.

   Output

   Chart shows build 6 red
   

When it is red 1

No test report files were found. Configuration error?

Cause. junit.xml was not written, or the path is wrong.

Fix, step by step

1. Check the test script uses jest-junit.
2. Run ls in the Test stage.

When it is red 2

No such DSL method 'cleanWs' found among steps

Cause. The Workspace Cleanup plugin is missing.

Fix, step by step

1. Install Workspace Cleanup.
2. Or use deleteDir().

When it is red 3

Timeout has been exceeded
Cancelling nested steps due to timeout

Cause. A step hung, like npm waiting for input.

Fix, step by step

1. Set CI=true.
2. Find the slow step with timestamps.

When it is red 4

cp: cannot stat dist/*: No such file or directory

Cause. Build did not create dist.

Fix, step by step

1. Check the build script.
2. Add ls -l dist after build.

Cleanup

1. Clear the lab live folder

   docker exec jenkins rm -rf /var/jenkins_home/lab-live/badge-node
   

   What it does: Removes the practice live copy.

   Output

   (no output)
   

2. Revert the broken test

   git revert --no-edit HEAD && git push
   

   What it does: Back to green.

   Output

   [main 8e1f0b2] Revert "test: break on purpose"
   

Practice tasks

Homework: try at home

Recap

• Build the Jenkinsfile in rounds.
• Use options for timeout, timestamps and history.
• Put junit in post always.
• Archive artifacts only on success.
• A failed stage skips the rest.

FAQ

Why junit in the stage post and not the pipeline post?

It runs right after tests even if they fail, and keeps the report next to the stage.

Do I need checkout scm in Declarative?

No, but writing it is clear. Use skipDefaultCheckout to control it.

Why disableConcurrentBuilds?

Two builds writing to the same live folder can mix files.

What does fingerprint do?

It lets you see which jobs used the same file.

Is the lab live folder a real deploy?

No. Real deploys go to servers with SSH, Docker or Kubernetes in later chapters.

Interview questions

1. Walk me through your Jenkinsfile.

   Checkout, install, build, test with junit, deploy step, post actions for archive, notify and cleanup, with timeout and history options.

2. How do you show tests in Jenkins?

   Write JUnit XML and call junit in post always.

3. How do you stop a hung build?

   timeout in options or around a step.

4. How do you save build output?

   archiveArtifacts with fingerprint in post success.

5. What happens after a failed stage?

   Later stages are skipped and post failure and always run.

Samajla ka?

Ravi Sir's Cards for this lesson

Revision cardInterview card

मराठी cards