What is Continuous Delivery vs Continuous Deployment in Jenkins - Hands-On Activity

Understanding Continuous Delivery vs Continuous Deployment with Jenkins

📖 Scenario: You are working as a DevOps engineer at a software company. Your team wants to automate the process of delivering software updates to users. You will learn the difference between Continuous Delivery and Continuous Deployment using Jenkins, a popular automation tool.

🎯 Goal: Build a simple Jenkins pipeline script that demonstrates the concepts of Continuous Delivery and Continuous Deployment by controlling when the software is automatically released to users.

📋 What You'll Learn

Create a Jenkins pipeline script with a variable to control deployment mode

Add a stage to build the software

Add a stage to deploy the software only if in Continuous Deployment mode

Print messages to show whether deployment is automatic or manual

💡 Why This Matters

🌍 Real World

Software teams use Jenkins pipelines to automate building and deploying applications. Understanding Continuous Delivery vs Continuous Deployment helps teams decide when to release software automatically or with manual checks.

💼 Career

DevOps engineers and automation specialists often configure Jenkins pipelines to implement Continuous Delivery or Continuous Deployment strategies, improving software release speed and reliability.

1

Create a Jenkins pipeline with a deployment mode variable

Create a Jenkins pipeline script and define a variable called deploymentMode with the value "Continuous Delivery".

Jenkins

# Define the deployment mode variable
deploymentMode = "Continuous Delivery"  # Your code here

Hint

Use the environment block to define the deploymentMode variable.

2

Add a build stage to the Jenkins pipeline

Add a stage called Build inside the stages block that prints "Building the software...".

Jenkins

pipeline {
    agent any
    environment {
        deploymentMode = "Continuous Delivery"
    }
    stages {
        stage('Build') {
            steps {
                // Print building message
                echo "Building the software..."  # Your code here
            }
        }
    }
}

Hint

Use stage('Build') and inside steps use echo to print the message.

3

Add a deploy stage that runs only in Continuous Deployment mode

Add a stage called Deploy that runs only if deploymentMode equals "Continuous Deployment". Inside, print "Automatically deploying the software...". Use when { expression { deploymentMode == 'Continuous Deployment' } } to control this.

Jenkins

pipeline {
    agent any
    environment {
        deploymentMode = "Continuous Delivery"
    }
    stages {
        stage('Build') {
            steps {
                echo "Building the software..."
            }
        }
        stage('Deploy') {
            when {
                expression { deploymentMode == 'Continuous Deployment' }
            }
            steps {
                // Print deployment message
                echo "Automatically deploying the software..."  # Your code here
            }
        }
    }
}

Hint

Use the when block with an expression to check deploymentMode.

4

Print the deployment mode and explain the difference

Add a post block with always that prints "Deployment mode is: " + deploymentMode and if deploymentMode is "Continuous Delivery", also print "Deployment requires manual approval." Otherwise, print "Deployment is automatic."

Jenkins

pipeline {
    agent any
    environment {
        deploymentMode = "Continuous Delivery"
    }
    stages {
        stage('Build') {
            steps {
                echo "Building the software..."
            }
        }
        stage('Deploy') {
            when {
                expression { deploymentMode == 'Continuous Deployment' }
            }
            steps {
                echo "Automatically deploying the software..."
            }
        }
    }
    post {
        always {
            // Print deployment mode and explanation
            script {
                echo "Deployment mode is: ${deploymentMode}"
                if (deploymentMode == 'Continuous Delivery') {
                    echo "Deployment requires manual approval."
                } else {
                    echo "Deployment is automatic."
                }
            }
        }
    }
}

Hint

Use the post block with always and a script block to run conditional echo commands.

Practice

1. What is the main difference between Continuous Delivery and Continuous Deployment?

easy

A. Continuous Delivery only builds code, Continuous Deployment only tests code.

B. Continuous Delivery deploys every change automatically, Continuous Deployment requires manual approval.

C. Continuous Delivery requires manual approval before production deployment, Continuous Deployment does not.

D. Continuous Delivery and Continuous Deployment are exactly the same.

Solution

1. Step 1: Understand Continuous Delivery

   Continuous Delivery automates preparing the software for release but waits for a manual step to deploy to production.

2. Step 2: Understand Continuous Deployment

   Continuous Deployment automates the entire process, including automatic deployment to production without manual approval.

3. Final Answer:

   Continuous Delivery requires manual approval before production deployment, Continuous Deployment does not. -> Option C

4. Quick Check:

   Manual approval = Continuous Delivery [OK]

Hint: Manual step means Continuous Delivery, no manual means Continuous Deployment [OK]

Common Mistakes:

• Confusing which process needs manual approval
• Thinking both deploy automatically
• Mixing build and deploy steps

2. Which Jenkins pipeline step is typically used to pause for manual approval in Continuous Delivery?

easy

A. input

B. deploy

C. build

D. test

Solution

1. Step 1: Identify Jenkins step for manual pause

   The input step in Jenkins pipeline pauses the pipeline and waits for user approval.

2. Step 2: Confirm other steps roles

   deploy runs deployment, build compiles code, test runs tests, none pause for approval.

3. Final Answer:

   input -> Option A

4. Quick Check:

   Manual approval step = input [OK]

Hint: Pause for approval uses 'input' step in Jenkins [OK]

Common Mistakes:

• Choosing deploy as manual step
• Confusing build or test with approval
• Not knowing Jenkins pipeline steps

3. Given this Jenkins pipeline snippet for Continuous Delivery:

stage('Deploy to Prod') {
  steps {
    input 'Approve deployment?'
    sh 'deploy.sh'
  }
}

What happens when this pipeline reaches the Deploy to Prod stage?

medium

A. The pipeline pauses and waits for manual approval before running deployment.

B. The pipeline fails with a syntax error.

C. The pipeline skips deployment and ends.

D. The deployment script runs immediately without pause.

Solution

1. Step 1: Analyze the input step in the stage

   The input 'Approve deployment?' pauses the pipeline and waits for a user to approve before continuing.

2. Step 2: Understand what happens after approval

   After approval, the shell script deploy.sh runs to deploy the application.

3. Final Answer:

   The pipeline pauses and waits for manual approval before running deployment. -> Option A

4. Quick Check:

   input step causes pause = The pipeline pauses and waits for manual approval before running deployment. [OK]

Hint: input step pauses pipeline until approval [OK]

Common Mistakes:

• Assuming deploy runs immediately
• Thinking pipeline skips deployment
• Confusing syntax error with input step

4. You have a Jenkins pipeline intended for Continuous Deployment but it includes this code:

stage('Deploy') {
  steps {
    input 'Approve deployment?'
    sh 'deploy.sh'
  }
}

What is the problem if you want full Continuous Deployment?

medium

A. The pipeline syntax is invalid and will fail.

B. The input step causes manual approval, breaking full automation.

C. The deploy.sh script is missing required parameters.

D. The stage name should be 'Continuous Deployment' instead of 'Deploy'.

Solution

1. Step 1: Identify manual approval in pipeline

   The input step pauses for manual approval, which is not allowed in full Continuous Deployment.

2. Step 2: Understand Continuous Deployment automation

   Continuous Deployment requires no manual steps; every change deploys automatically.

3. Final Answer:

   The input step causes manual approval, breaking full automation. -> Option B

4. Quick Check:

   Manual approval breaks Continuous Deployment [OK]

Hint: No manual steps allowed in Continuous Deployment [OK]

Common Mistakes:

• Thinking syntax error causes failure
• Assuming deploy.sh script is the problem
• Confusing stage name with functionality

5. You want to convert a Jenkins pipeline from Continuous Delivery to Continuous Deployment. Which change should you make?

hard

A. Rename the pipeline to 'Continuous Deployment' without changing steps.

B. Add more manual approval steps to ensure safety.

C. Change the build step to run tests only.

D. Remove the manual input approval step so deployment runs automatically.

Solution

1. Step 1: Identify manual approval in Continuous Delivery

   Continuous Delivery pipelines pause for manual approval using the input step.

2. Step 2: Remove manual approval for Continuous Deployment

   To achieve Continuous Deployment, remove the input step so deployment happens automatically after tests.

3. Final Answer:

   Remove the manual input approval step so deployment runs automatically. -> Option D

4. Quick Check:

   Remove manual steps for Continuous Deployment [OK]

Hint: Remove input step to automate deployment fully [OK]

Common Mistakes:

• Adding manual steps instead of removing
• Changing unrelated build steps
• Only renaming pipeline without changing logic