Build, test, deploy stages concept in Jenkins - Step-by-Step Execution

Process Flow - Build, test, deploy stages concept

Start Pipeline

↓

Build Stage

↓

Test Stage

↓

Deploy Stage

↓

Pipeline Complete

The pipeline runs in order: first building the code, then testing it, and finally deploying it if tests pass.

Execution Sample

Jenkins

pipeline {
  agent any
  stages {
    stage('Build') { steps { echo 'Building...' } }
    stage('Test') { steps { echo 'Testing...' } }
    stage('Deploy') { steps { echo 'Deploying...' } }
  }
}

This Jenkins pipeline runs three stages: Build, Test, and Deploy, printing messages at each step.

Process Table

Step	Stage	Action	Output	Next Step
1	Build	Start Build stage	Building...	Go to Test stage
2	Test	Start Test stage	Testing...	Go to Deploy stage
3	Deploy	Start Deploy stage	Deploying...	Pipeline Complete
4	End	Pipeline finished	All stages completed successfully	Stop

💡 Pipeline stops after Deploy stage completes successfully.

Status Tracker

Variable	Start	After Build	After Test	After Deploy
stageStatus	none	build complete	test complete	deploy complete

Key Moments - 2 Insights

Why does the pipeline stop if the Test stage fails?

Because Jenkins runs stages sequentially and stops the pipeline on failure to avoid deploying broken code, as shown by the absence of Deploy stage execution in the table if Test fails.

Can Deploy run before Test finishes?

No, stages run one after another. Deploy only starts after Test completes successfully, as seen in the execution_table step order.

Visual Quiz - 3 Questions

Look at the execution table, what is the output at Step 2?

A Testing...

B Building...

C Deploying...

D Pipeline finished

💡 Hint

Check the 'Output' column for Step 2 in the execution_table.

At which step does the pipeline complete all stages?

A Step 3

B Step 2

C Step 4

D Step 1

💡 Hint

Look at the 'Next Step' column and find where it says 'Stop'.

If the Test stage fails, what happens to the Deploy stage?

A It runs anyway

B It is skipped

C It runs before Test

D It runs twice

💡 Hint

Refer to the key_moments section explaining pipeline stop on failure.

Concept Snapshot

Jenkins pipeline runs stages in order: Build -> Test -> Deploy.
Each stage must succeed for the next to run.
If a stage fails, pipeline stops to prevent errors.
Stages print messages to show progress.
This ensures safe, step-by-step delivery of code.

Full Transcript

This Jenkins pipeline example shows three main stages: Build, Test, and Deploy. The pipeline starts by running the Build stage, which compiles or prepares the code. Next, it runs the Test stage to check if the code works correctly. If tests pass, the Deploy stage runs to release the code to users. The execution table traces each step, showing the output messages and the order of stages. Variables track the status after each stage. Key moments clarify that the pipeline stops if tests fail, preventing deployment of broken code. The visual quiz checks understanding of outputs and stage order. This stepwise flow helps beginners see how Jenkins pipelines automate safe software delivery.

Practice

1. What is the main purpose of splitting a Jenkins pipeline into build, test, and deploy stages?

easy

A. To organize the process into clear steps and catch errors early

B. To run all commands at the same time for speed

C. To skip testing and deploy directly

D. To only build the code without testing or deploying

Solution

1. Step 1: Understand the purpose of stages

   Stages separate the pipeline into logical parts: building, testing, and deploying.

2. Step 2: Recognize benefits of stages

   This separation helps find errors early and keeps the process organized.

3. Final Answer:

   To organize the process into clear steps and catch errors early -> Option A

4. Quick Check:

   Stages = clear steps + early error detection [OK]

Hint: Stages split work to catch errors early and stay organized [OK]

Common Mistakes:

• Thinking stages run in parallel by default
• Skipping test stage to save time
• Confusing build with deploy

2. Which of the following is the correct syntax to define a build stage in a Jenkins declarative pipeline?

easy

A. stage('build') { steps { sh 'make build' } }

B. build { stage('steps') { sh 'make build' } }

C. steps { stage('build') { sh 'make build' } }

D. pipeline { build { sh 'make build' } }

Solution

1. Step 1: Recall Jenkins declarative syntax

   A stage is defined as stage('name') { steps { ... } }.

2. Step 2: Match syntax with options

   stage('build') { steps { sh 'make build' } } correctly uses stage('build') { steps { sh 'make build' } }.

3. Final Answer:

   stage('build') { steps { sh 'make build' } } -> Option A

4. Quick Check:

   Stage syntax = stage('name') + steps block [OK]

Hint: Stage syntax: stage('name') { steps { ... } } [OK]

Common Mistakes:

• Placing steps outside stage block
• Using build as a block instead of stage
• Missing steps keyword

3. Given this Jenkins pipeline snippet:

pipeline {
  agent any
  stages {
    stage('build') {
      steps {
        echo 'Building...'
      }
    }
    stage('test') {
      steps {
        error 'Test failed!'
      }
    }
    stage('deploy') {
      steps {
        echo 'Deploying...'
      }
    }
  }
}

What will be the output when this pipeline runs?

medium

A. Pipeline skips build and test, runs deploy only

B. All stages run successfully including deploy

C. Build stage runs, then test stage fails and stops pipeline; deploy does not run

D. Pipeline runs build and deploy but skips test

Solution

1. Step 1: Analyze build stage

   The build stage prints 'Building...' successfully.

2. Step 2: Analyze test stage

   The test stage runs error 'Test failed!' which stops the pipeline with failure.

3. Step 3: Analyze deploy stage

   Because test failed, deploy stage does not run.

4. Final Answer:

   Build stage runs, then test stage fails and stops pipeline; deploy does not run -> Option C

5. Quick Check:

   Failure in test stops pipeline before deploy [OK]

Hint: Error in test stage stops pipeline before deploy [OK]

Common Mistakes:

• Assuming deploy runs despite test failure
• Thinking error only logs message without stopping
• Ignoring pipeline stop on error

4. You wrote this Jenkins pipeline snippet:

pipeline {
  agent any
  stages {
    stage('build') {
      steps {
        sh 'make build'
      }
    }
    stage('test') {
      sh 'make test'
    }
    stage('deploy') {
      steps {
        sh 'make deploy'
      }
    }
  }
}

Why does this pipeline fail to run correctly?

medium

A. The build stage uses sh instead of bat

B. The test stage is missing the steps block

C. The deploy stage should be outside stages

D. The agent keyword is misplaced

Solution

1. Step 1: Check syntax of each stage

   Build and deploy stages have steps { ... } blocks, but test stage does not.

2. Step 2: Understand Jenkins syntax rules

   Each stage must have a steps block to run commands; missing it causes failure.

3. Final Answer:

   The test stage is missing the steps block -> Option B

4. Quick Check:

   Missing steps block in stage = syntax error [OK]

Hint: Every stage needs a steps block for commands [OK]

Common Mistakes:

• Forgetting steps block inside a stage
• Mixing shell commands syntax
• Misplacing agent keyword

5. You want to create a Jenkins pipeline that builds your app, runs tests, and deploys only if tests pass. Which pipeline structure below correctly implements this with proper stages and error handling?

hard

A. pipeline { agent any stages { stage('build') { steps { sh 'build.sh' } } stage('test') { steps { sh 'test.sh' } } stage('deploy') { steps { sh 'deploy.sh' } } } }

B. pipeline { agent any stages { stage('build') { steps { sh 'build.sh' } } stage('test') { steps { sh 'test.sh' } } stage('deploy') { steps { sh 'deploy.sh' } } } post { failure { echo 'Tests failed, skipping deploy' } } }

C. pipeline { agent any stages { stage('build') { steps { sh 'build.sh' } } stage('test') { steps { sh 'test.sh' } } stage('deploy') { steps { sh 'deploy.sh' } } } post { always { echo 'Deploying regardless of test result' } } }

D. pipeline { agent any stages { stage('build') { steps { sh 'build.sh' } } stage('test') { steps { sh 'test.sh' } } stage('deploy') { steps { sh 'deploy.sh' } } } post { success { echo 'Deployment complete' } } }

Solution

1. Step 1: Understand pipeline flow

   Build runs first, then test, then deploy only if test passes (pipeline success).

2. Step 2: Analyze post blocks

   pipeline { agent any stages { stage('build') { steps { sh 'build.sh' } } stage('test') { steps { sh 'test.sh' } } stage('deploy') { steps { sh 'deploy.sh' } } } post { success { echo 'Deployment complete' } } } uses post { success { ... } } to confirm deployment success message, matching requirement.

3. Step 3: Check other options

   pipeline { agent any stages { stage('build') { steps { sh 'build.sh' } } stage('test') { steps { sh 'test.sh' } } stage('deploy') { steps { sh 'deploy.sh' } } } } lacks error handling; B prints message on failure but does not prevent deploy; C deploys always.

4. Final Answer:

   Option D correctly runs deploy only on success and confirms deployment -> Option D

5. Quick Check:

   Deploy runs only if tests pass = post success block [OK]

Hint: Use post success block to run deploy only if tests pass [OK]

Common Mistakes:

• Deploy running even if tests fail
• Missing post blocks for error handling
• Confusing post always with success