CI/CD pipeline basics in Spring Boot - Step-by-Step Execution

Concept Flow - CI/CD pipeline basics

Code Commit

↓

Build Stage

↓

Test Stage

↓

Deploy Stage

↓

Production Environment

The CI/CD pipeline starts with code commit, then builds the code, runs tests, and finally deploys to production.

Execution Sample

Spring Boot

git add .
git commit -m "Add feature"
./mvnw clean package
./mvnw test
kubectl apply -f deployment.yaml

This sequence adds changes, commits code, builds the Spring Boot app, runs tests, and deploys to Kubernetes.

Execution Table

Step	Action	Command	Result	Next Step
1	Commit code	git commit -m "Add feature"	Code saved in repo	Build Stage
2	Build app	./mvnw clean package	Jar file created	Test Stage
3	Run tests	./mvnw test	All tests passed	Deploy Stage
4	Deploy app	kubectl apply -f deployment.yaml	App running in production	End
5	End	-	Pipeline complete	-

💡 Pipeline ends after successful deployment to production.

Variable Tracker

Variable	Start	After Step 1	After Step 2	After Step 3	After Step 4
Code State	Local changes	Committed	Built	Tested	Deployed
Build Artifact	None	None	Jar created	Jar created	Jar deployed
Test Status	Not run	Not run	Not run	Passed	Passed
Deployment Status	Not deployed	Not deployed	Not deployed	Not deployed	Running

Key Moments - 3 Insights

Why do we build the code before testing?

Building creates the executable file needed for tests; see execution_table step 2 and 3 where build produces the jar, then tests run on it.

What happens if tests fail?

The pipeline stops before deployment; in the table, if step 3 tests fail, step 4 deploy won't run.

Why deploy only after tests pass?

To ensure only working code reaches production, as shown by the flow from step 3 to 4 in execution_table.

Visual Quiz - 3 Questions

Look at the execution table, what is the result after step 2?

A Jar file created

B Code saved in repo

C All tests passed

D App running in production

💡 Hint

Check the 'Result' column for step 2 in the execution_table.

At which step does the pipeline deploy the app?

A Step 1

B Step 4

C Step 3

D Step 5

💡 Hint

Look at the 'Action' column to find when deployment happens.

If tests fail at step 3, what happens next?

A Pipeline continues to deploy

B Build stage repeats

C Pipeline stops before deployment

D Code is committed again

💡 Hint

Refer to key_moments about test failure stopping the pipeline.

Concept Snapshot

CI/CD pipeline basics:
1. Commit code to start pipeline.
2. Build compiles code into executable.
3. Test verifies code correctness.
4. Deploy moves app to production.
Pipeline stops if tests fail to keep production safe.

Full Transcript

A CI/CD pipeline automates software delivery. It starts when code is committed. Then the build stage compiles the code into a runnable file. Next, tests run to check for errors. If tests pass, the app is deployed to production. If tests fail, deployment stops to avoid errors in production. This flow ensures fast and safe delivery of software updates.

Practice

1. What is the main purpose of a CI/CD pipeline in a Spring Boot project?

easy

A. To automate building, testing, and deploying the application

B. To write the application code manually

C. To design the user interface of the application

D. To manage database schemas manually

Solution

1. Step 1: Understand CI/CD pipeline role

   A CI/CD pipeline automates repetitive tasks like building, testing, and deploying software.

2. Step 2: Match with Spring Boot context

   In Spring Boot projects, this automation helps deliver updates faster and catch errors early.

3. Final Answer:

   To automate building, testing, and deploying the application -> Option A

4. Quick Check:

   CI/CD pipeline = automation of build, test, deploy [OK]

Hint: CI/CD means automate build, test, deploy steps [OK]

Common Mistakes:

• Confusing CI/CD with coding or UI design
• Thinking CI/CD manages database manually
• Assuming CI/CD replaces writing code

2. Which of the following is the correct syntax to define a stage in a Jenkins pipeline for building a Spring Boot app?

easy

A. step('Build') { execute 'mvn clean package' }

B. buildStage { run 'mvn clean package' }

C. pipelineStage('Build') { shell 'mvn clean package' }

D. stage('Build') { steps { sh 'mvn clean package' } }

Solution

1. Step 1: Recall Jenkins pipeline syntax

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

2. Step 2: Verify correct command inside steps

   The shell command sh 'mvn clean package' is correct for building a Spring Boot app with Maven.

3. Final Answer:

   stage('Build') { steps { sh 'mvn clean package' } } -> Option D

4. Quick Check:

   Jenkins stage syntax = stage + steps + sh [OK]

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

Common Mistakes:

• Using incorrect keywords like buildStage or pipelineStage
• Missing steps block inside stage
• Using run or execute instead of sh for shell commands

3. Given this Jenkins pipeline snippet:

pipeline {
  agent any
  stages {
    stage('Test') {
      steps {
        sh 'mvn test'
      }
    }
  }
}

What will happen when this pipeline runs?

medium

A. It builds the application without testing

B. It runs Maven tests and reports results

C. It deploys the application to production

D. It fails because 'mvn test' is invalid

Solution

1. Step 1: Analyze the pipeline stage

   The stage named 'Test' runs the shell command mvn test, which executes tests in Maven.

2. Step 2: Understand the pipeline effect

   Running mvn test triggers tests and generates test reports if any.

3. Final Answer:

   It runs Maven tests and reports results -> Option B

4. Quick Check:

   mvn test = run tests [OK]

Hint: mvn test runs tests, not build or deploy [OK]

Common Mistakes:

• Confusing test stage with build or deploy
• Thinking 'mvn test' is invalid command
• Assuming deployment happens automatically

4. You wrote this Jenkins pipeline snippet:

stage('Build') {
  sh 'mvn clean package'
}

But Jenkins shows an error. What is the likely cause?

medium

A. Missing steps block inside the stage

B. Wrong shell command syntax

C. Agent not specified in pipeline

D. Maven is not installed on Jenkins server

Solution

1. Step 1: Check Jenkins stage syntax

   Each stage must contain a steps { ... } block to run commands.

2. Step 2: Identify missing steps block

   The snippet lacks steps { }, causing Jenkins syntax error.

3. Final Answer:

   Missing steps block inside the stage -> Option A

4. Quick Check:

   Jenkins stage needs steps block [OK]

Hint: Always wrap commands inside steps { } in Jenkins stage [OK]

Common Mistakes:

• Omitting steps block inside stage
• Assuming shell command syntax is wrong
• Ignoring agent requirement (not error here)

5. You want to create a Jenkins pipeline that builds, tests, and deploys a Spring Boot app only if tests pass. Which pipeline structure achieves this?

hard

A. pipeline {
agent any
stages {
stage('Build') { steps { sh 'mvn clean package' } }
stage('Deploy') { steps { sh './deploy.sh' } }
stage('Test') { steps { sh 'mvn test' } }
}
}

B. pipeline {
agent any
stages {
stage('Test') { steps { sh 'mvn test' } }
stage('Deploy') { steps { sh './deploy.sh' } }
stage('Build') { steps { sh 'mvn clean package' } }
}
}

C. pipeline {
agent any
stages {
stage('Build') { steps { sh 'mvn clean package' } }
stage('Test') { steps { sh 'mvn test' } }
stage('Deploy') { steps { sh './deploy.sh' } }
}
}

D. pipeline {
agent any
stages {
stage('Deploy') { steps { sh './deploy.sh' } }
stage('Build') { steps { sh 'mvn clean package' } }
stage('Test') { steps { sh 'mvn test' } }
}
}

Solution

1. Step 1: Understand stage order importance

   Build must happen before testing, and deploy only after tests pass.

2. Step 2: Check pipeline stage sequence

   pipeline { agent any stages { stage('Build') { steps { sh 'mvn clean package' } } stage('Test') { steps { sh 'mvn test' } } stage('Deploy') { steps { sh './deploy.sh' } } } } has Build, then Test, then Deploy in correct order ensuring deploy runs only if tests succeed.

3. Final Answer:

   Build, Test, then Deploy in sequence -> Option C

4. Quick Check:

   Correct stage order ensures safe deploy [OK]

Hint: Deploy only after successful test stage [OK]

Common Mistakes:

• Deploying before tests run
• Running tests after deploy
• Incorrect stage order breaking pipeline logic