Lab-2-1

(10 % of the course mark)

Jenkins Pipelines

• This lab introduces Jenkins Pipelines for automating CI/CD workflows. Participants will create and configure a Jenkinsfile to define build, test, and deployment stages using Declarative or Scripted Pipelines.

Lab objectives

• Understand the fundamentals of Jenkins Pipelines.

• Write and execute a basic Jenkinsfile.

• Integrate version control into the pipeline. ie: Git.

• Automate build, test, and deployment processes.

• Utilize pipeline stages, steps, and environment variables.

warning

• Ensure that you have successfully completed the Lab Prerequisites, which describe how to install the Docker Desktop app, download the Jenkins image, and create a Jenkins container. Also, make sure that the Jenkins container is running.

Jenkins Setup

1. Open the terminal and type the command below and press enter. This should output a string of numbers and letters, this is the default password for the Jenkins server, copy this password and save it to a file.

docker exec jenkins-container cat /var/jenkins_home/secrets/initialAdminPassword

2. Open your browser and enter the url: http://localhost:8080 and use the password that was saved from step 1 to unlock the server.

3. When presented with an option to customize Jenkins and to install plugins, close the dialog. We will install the plugins later.

4. Click on Start using Jenkins.

Install Plugins

1. Click on Manage Jenkins > Plugins > Available plugins.

2. On the search bar enter the text: Pipeline.

3. Install the following plugins.

4. Click on Install, this should automatically download and install the plugin. Wait until it is finished with the installation.

5. Go back to the Available plugins.

6. On the search bar enter the text: NodeJS.

7. Install the following plugin.

8. Click on Install, this should automatically download and install the plugin. Wait until it is finished with the installation.

9. Go back to the Available plugins.

10. On the search bar enter the text: Git.

11. Click on Install, this should automatically download and install the plugin. Wait until it is finished with the installation.

12. Click on Manage Jenkins > Tools.

13. Scroll down to the NodeJS installations section, and click on Add NodeJS.

14. Set the Name as NodeJS and choose the latest version of NodeJS.

15. Click on Save.

Hello World - Scripted Pipeline

1. Click on Dashboard > New Item.

2. Set the item name as: hello-world-scripted-pipeline.

3. Choose Pipeline and click on OK.

4. Scroll down until the Script text area is visible, copy and paste the code below:

node {
    stage('Build') {
        echo 'Hello, World!'
    }
}

5. Click on Save.

6. On the left side of the screen, click on Build Now.

7. Take a screenshot of the successful execution of the pipeline item and name it hello-world-scripted-pipeline.png.

8. Hover the mouse to the build stage of the pipeline to see the logs, Click on Log, take a screenshot and name it hello-world-scripted-pipeline-logs.png.

Hello World - Declarative Pipeline

1. Click on Dashboard > New Item.

2. Set the item name as: hello-world-declarative-pipeline.

3. Choose Pipeline and click on OK.

4. Scroll down until the Script text area is visible, copy and paste the code below:

pipeline {
    agent any

    stages {
        stage('Build') {
            steps {
                echo 'Hello, World!'
            }
        }
    }
}

5. Click on Save.

6. On the left side of the screen, click on Build Now.

7. Take a screenshot of the successful execution of the pipeline item and name it hello-world-declarative-pipeline.png.

8. Hover the mouse to the build stage of the pipeline to see the logs, Click on Log, take a screenshot and name it hello-world-declarative-pipeline-logs.png.

tip

• Most teams prefer Declarative Pipelines because they are simpler, more readable, and easier to maintain.

Advanced Declarative Pipeline

note

• The declarative pipeline that we are going to define has the following tasks / characteristics:

• Stages:

  • Checkout - Download the source code from GitHub repo.

  • Build - Execute the command to build the app.

  • Test - Run the test cases for the app.

  • Deploy - Deploy the app to the remote server. For now this step is just a placeholder but normally it should have commands to login to the remote server via SSH and then copy the files over and execute commands to restart the app.

• Uses environment variables to define the repo url and branch name.

• Uses the NodeJS plugin tool which is used for building the app.

• Uses a post action which has a success and failure task for accurate logging.

1. Click on Dashboard > New Item.

2. Set the item name as: advanced-declarative-pipeline.

3. Choose Pipeline and click on OK.

4. Scroll down until the Script text area is visible, copy and paste the code below:

pipeline {
    agent any

    tools {
        nodejs 'NodeJS'
    }

    environment {
        REPO_URL = 'https://github.com/roderickkit-bernardo/jenkins-app.git'
        BRANCH = 'main'
    }

    stages {
        stage('Checkout') {
            steps {
                git branch: "${BRANCH}", url: "${REPO_URL}"
            }
        }

        stage('Build') {
            steps {
                echo 'Building the project...'
                sh 'npm install'
            }
        }

        stage('Test') {
            steps {
                echo 'Running tests...'
                sh 'npm test'
            }
        }

        stage('Deploy') {
            steps {
                echo 'Deploying application...'
            }
        }
    }

    post {
        success {
            echo 'Pipeline completed successfully! 🎉'
        }
        failure {
            echo 'Pipeline failed! Check logs for details. ❌'
        }
    }
}

5. Click on Save.

6. On the left side of the screen, click on Build Now.

7. Take a screenshot of the successful execution of the pipeline item and name it advanced-declarative-pipeline.png.

8. This pipeline has many stages, hovering the mouse at each stage to see the Logs button and to be able to view the logs. Take a screenshot of the logs at each stage and name it: advanced-declarative-pipeline-logs-xxxxx.png where xxxxx is the name of the stage.

Submission

1. Create a folder named submit.

2. Copy all (hello-world-scripted-pipeline.png, hello-world-scripted-pipeline-logs.png, hello-world-declarative-pipeline.png, hello-world-declarative-pipeline-logs.png, advanced-declarative-pipeline.png, advanced-declarative-pipeline-logs-tools.png, advanced-declarative-pipeline-logs-checkout.png, advanced-declarative-pipeline-logs-build.png, advanced-declarative-pipeline-logs-test.png, advanced-declarative-pipeline-logs-deploy.png and advanced-declarative-pipeline-logs-post.png) the previously saved screenshots to this folder.

3. Create a zip file of this folder.

4. Navigate back to where the lab was originally downloaded, there should be a Submissions section (see below) where the zip file can be uploaded.