CI/CD tools landscape in Jenkins - Step-by-Step Execution

Process Flow - CI/CD tools landscape

Code Commit

↓

Trigger CI Server

↓

Build & Test

↓

If Tests Pass?

No→Notify Failure

Yes↓

Deploy to Staging

↓

Manual or Auto Approval?

No→Wait

Yes↓

Deploy to Production

↓

Notify Success

This flow shows how code changes trigger automated build, test, and deployment steps with checks and notifications.

Execution Sample

Jenkins

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

A simple Jenkins pipeline that runs build, test, and deploy steps in order.

Process Table

Step	Action	Stage	Output	Next Step
1	Start pipeline	N/A	Pipeline started	Build stage
2	Run build	Build	Building...	Test stage
3	Run tests	Test	Testing...	Deploy stage
4	Run deploy	Deploy	Deploying...	Pipeline complete
5	End pipeline	N/A	Pipeline finished successfully	Exit

💡 Pipeline completes after deploy stage with success notification.

Status Tracker

Variable	Start	After Step 2	After Step 3	After Step 4	Final
pipeline_status	Not started	Building	Testing	Deploying	Success

Key Moments - 2 Insights

Why does the pipeline stop if tests fail?

The pipeline checks test results after the Test stage (see step 3 in execution_table). If tests fail, it triggers failure notification and stops to prevent bad code deployment.

What triggers the deployment stage?

Deployment runs only after successful tests (step 4 in execution_table). This ensures only verified code is deployed.

Visual Quiz - 3 Questions

Look at the execution table, what is the pipeline_status after Step 3?

A Testing

B Building

C Deploying

D Success

💡 Hint

Check variable_tracker column 'After Step 3' for pipeline_status.

At which step does the pipeline finish successfully?

A Step 3

B Step 4

C Step 5

D Step 2

💡 Hint

Look at execution_table row with 'Pipeline finished successfully' output.

If tests fail at Step 3, what would happen next?

A Proceed to Deploy stage

B Notify failure and stop pipeline

C Restart Build stage

D Skip Test stage

💡 Hint

Refer to key_moments explanation about pipeline stopping on test failure.

Concept Snapshot

CI/CD pipelines automate code build, test, and deployment.
Code commit triggers pipeline start.
Build and test stages verify code.
Deploy stage runs only if tests pass.
Failures stop pipeline and notify team.
Jenkins pipelines define these steps in stages.

Full Transcript

This visual execution shows a Jenkins CI/CD pipeline flow. When code is committed, the pipeline starts and runs the Build stage, outputting 'Building...'. Next, it runs the Test stage with 'Testing...'. If tests pass, it proceeds to Deploy stage with 'Deploying...'. Finally, the pipeline finishes successfully. Variables track pipeline status changing from Not started to Building, Testing, Deploying, and Success. Key moments clarify that the pipeline stops if tests fail to avoid deploying bad code. The visual quiz checks understanding of pipeline status at steps and behavior on test failure.

Practice

1. What is the main purpose of CI/CD tools like Jenkins in software development?

easy

A. To design user interfaces

B. To write code manually

C. To automate building, testing, and deploying software

D. To manage hardware resources

Solution

1. Step 1: Understand CI/CD tools role

   CI/CD tools automate repetitive tasks in software development like building, testing, and deploying.

2. Step 2: Compare options

   Options B, C, and D describe unrelated tasks. Only To automate building, testing, and deploying software matches the automation purpose.

3. Final Answer:

   To automate building, testing, and deploying software -> Option C

4. Quick Check:

   CI/CD tools automate software delivery = A [OK]

Hint: CI/CD tools automate software delivery steps [OK]

Common Mistakes:

• Confusing CI/CD tools with coding or design tools
• Thinking CI/CD tools manage hardware
• Assuming CI/CD tools replace developers

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

easy

A. stage('Build') { steps { echo 'Building...' } }

B. step('Build') { echo 'Building...' }

C. stage: Build { echo 'Building...' }

D. buildStage { echo 'Building...' }

Solution

1. Step 1: Recall Jenkins pipeline syntax

   Jenkins uses stage('name') { steps { ... } } to define stages.

2. Step 2: Check options for correct syntax

   Only stage('Build') { steps { echo 'Building...' } } matches the correct syntax with stage and steps blocks.

3. Final Answer:

   <code>stage('Build') { steps { echo 'Building...' } }</code> -> Option A

4. Quick Check:

   Correct Jenkins stage syntax = C [OK]

Hint: Stages use stage('name') with steps block [OK]

Common Mistakes:

• Using 'step' instead of 'stage'
• Missing the steps block inside stage
• Incorrect block syntax with colons or missing braces

3. Given this Jenkins pipeline snippet, what will be printed during the 'Test' stage?

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

medium

A. Testing... Building...

B. Testing...

C. Building...

D. Building... Testing...

Solution

1. Step 1: Understand pipeline stage order

   The pipeline runs stages in order: 'Build' then 'Test'.

2. Step 2: Identify echo outputs

   'Build' stage prints 'Building...', 'Test' stage prints 'Testing...'. Both run sequentially.

3. Final Answer:

   Building... Testing... -> Option D

4. Quick Check:

   Stages run in order, print messages in sequence = B [OK]

Hint: Stages run sequentially, outputs print in order [OK]

Common Mistakes:

• Assuming stages run in parallel by default
• Mixing output order
• Ignoring all stages run unless skipped

4. Identify the error in this Jenkins pipeline snippet:

pipeline {
  agent any
  stages {
    stage('Deploy') {
      step { echo 'Deploying...' }
    }
  }
}

medium

A. The keyword should be 'steps' not 'step'

B. Missing agent declaration

C. Stage name must be lowercase

D. Echo command is invalid

Solution

1. Step 1: Check pipeline syntax for stages

   Inside a stage, the correct block is steps (plural), not step.

2. Step 2: Verify other parts

   Agent is declared, stage name case is allowed, echo is valid. Only 'step' is wrong.

3. Final Answer:

   The keyword should be 'steps' not 'step' -> Option A

4. Quick Check:

   Use 'steps' block inside stage = A [OK]

Hint: Inside stage use 'steps' plural block [OK]

Common Mistakes:

• Using 'step' instead of 'steps'
• Thinking stage names must be lowercase
• Assuming echo is not allowed

5. You want to create a Jenkins pipeline that builds, tests, and deploys only if tests pass. Which approach best fits this CI/CD workflow?

hard

A. Skip Test stage and deploy immediately after Build

B. Define sequential stages: Build, Test, Deploy; Deploy runs only if Test succeeds

C. Deploy first, then Build and Test in any order

D. Run Build and Deploy stages in parallel, then Test last

Solution

1. Step 1: Understand CI/CD workflow logic

   Tests must pass before deploying to avoid broken releases.

2. Step 2: Choose pipeline structure

   Sequential stages Build -> Test -> Deploy ensure deploy runs only if tests succeed.

3. Step 3: Evaluate other options

   Parallel or skipping tests risks deploying broken code; deploying first is illogical.

4. Final Answer:

   Define sequential stages: Build, Test, Deploy; Deploy runs only if Test succeeds -> Option B

5. Quick Check:

   Sequential stages with test gate = D [OK]

Hint: Deploy only after successful tests in sequence [OK]

Common Mistakes:

• Running deploy before tests
• Skipping tests to save time
• Running build and deploy in parallel