Setting up a Job in Jenkins

How to create a Jenkins CI/CD pipeline

Step 1 - Install Java onto ec2 instance server

Ubuntu 18.04 includes Open JDK 11, which is an open-source variant of the JRE and JDK. To install this version, first update the package index:

• sudo apt update check if Java is already installed: java --version
• If Java is not currently installed sudo apt install default-jre
• To verify java --version
• install jdk sudo apt install default-jdk
• To verify javac -version

Step 2 Install Jenkins on Ubuntu 18.04

1. Installing Jenkins

• First, add the repository key to the system: wget -q -O - https://pkg.jenkins.io/debian-stable/jenkins.io.key | sudo apt-key add -

• When the key is added, the system will return OK. Next, append the Debian package repository address to the server’s sources.list: sudo sh -c 'echo deb http://pkg.jenkins.io/debian-stable binary/ > /etc/apt/sources.list.d/jenkins.list'

• sudo apt update

• sudo apt install jenkins

  • For Long Term Support release:

curl -fsSL https://pkg.jenkins.io/debian-stable/jenkins.io.key | sudo tee \ /usr/share/keyrings/jenkins-keyring.asc > /dev/null echo deb [signed-by=/usr/share/keyrings/jenkins-keyring.asc] \ https://pkg.jenkins.io/debian-stable binary/ | sudo tee \ /etc/apt/sources.list.d/jenkins.list > /dev/null sudo apt-get update sudo apt-get install jenkins

`

2. - Starting Jenkins

• sudo systemctl daemon-reload
• sudo systemctl start jenkins
• sudo systemctl status jenkins

3. Opening the Firewall

• sudo ufw allow 8080
• sudo ufw status
• if firewall inactive run these commands: sudo ufw allow OpenSSH sudo ufw enable

4. Setting Up Jenkins

• visit Jenkins on its default port, 8080, using your server domain name or IP address: http://your_server_ip_or_domain:8080

• sudo cat /var/lib/jenkins/secrets/initialAdminPassword

• Copy the 32-character alphanumeric password from the terminal and paste it into the Administrator password field, then click Continue.

• On the left-hand side, click Manage Jenkins, and then click Manage Plugins.

• Click on the Available tab, and then enter node plugin at the top right.

• elect the checkbox next to node.js plugin, and then click Install without restart.

https://www.digitalocean.com/community/tutorials/how-to-install-jenkins-on-ubuntu-18-04

Step 3 - Generate a new key

Generate a new ssh key in your localhost ssh-keygen -t ed25519 -C "[email protected]"

Step 4 - Copy Key into Github

Go into your repo and select Settings

Select Deploy Keys and select Add deploy key

Copy the public ssh key into key and title ssh-jenkins

Now select Add key

Step 5 - Connect to Jenckins

Create a new Jenkins item and select Freestyle Project Set up the following configurations:

Discard old builds: 3

Github project: Insert GitHub HTTPS repo link

Restrict where this project can be run: logical expression to specify which agent to execute builds of the project (e.g. sparta-ubuntu-node)

Git:

• Repository URL: Insert GitHub SSH repo link

• Credential: Add -> Jenkins -> Key -> Insert private ssh key

Branches to build: */main

Github hook trigger for GITScm polling: check this option

Step 6 - Setting Up a Webhook:

Setting up the webhook allows GitHub to trigger Jenkins to start a new build whenever a new commit is pushed.

• In the GitHub repository that is to be linked to Jenkins, create a new Webhook (Settings-->Webhooks-->Add webhook)

• Payload URL: Add the URL (usually specified with ip and port) with /github-webhook/ appended at the end ie http://18.130.227.98:8080/github-webhook/

Content type: Select application/json

• Any new pushes to the repository should now trigger a new build, shown in

• Build History where the Console Output can be read for each individual build

Step 7 - Creating Jenkins Jobs

1. On the Jenkins Dashboard, click on New Item
2. Enter a the name in convetion for the job
3. Select Freestyle project
4. Click Ok
5. Create a job for CI, merging and deployment

Step 8 - Continuous Integration (CI) Job

General

1. Click Discard old builds and keep the max number of build to 2
2. Click GitHub project and add the HTTP URL of the repository Office 365 Connector

Click Restrict where this project can be run, then set it as sparta-ubuntu-node

Source Code Management

1. Select Git
2. In Repositories:

• Repository URL: insert the SSH URL from GitHub

• Credentials:

  • Next to Credentials, click Add > Jenkins
  • Select Kind as SSH Username with private key
  • Set a suitable description and enter the private key directly. The private key is in your ~/.ssh directory. Ensure that the begin and end text of the key is included.
  • With the credential added, select the one you created

  

• Branches to build: set to */dev (dev branch)

Build Triggers

• Click GitHub hook trigger for GITScm polling

Build Environment

• Click Provide Node & npm bin/ folder to PATH

Build

1. Click Add build step > Execute Shell
2. In command, enter the following code:

cd app npm install npm test

Post-build Actions

1. Select Add post-build action > Build other projects
2. Insert the project name for the merge job
3. Ensure Trigger only if build is stable is selected

Step 9 - Merge Job

General

1. Click Discard old builds and keep the max number of build to 2
2. Click GitHub project and add the HTTP URL of the repository

Office 365 Connector Click Restrict where this project can be run, then set it as sparta-ubuntu-node

Source Code Management

1. Select Git
2. In Repositories:

• Repository URL: insert the SSH URL
• Credentials: select the credential you created earlier Branches to build: set to */dev (dev branch)

Build Environment Select Provide Node & npm bin/ folder to PATH

Post-build Actions

1. First, select Add post-build action > Git Publisher
2. Click Push Only If Build Succeeds
3. In Branches:

• Branch to push: main
• Target remote name: origin

4. Next, select Add post-build action > Build other projects
5. Insert the project name for the deploy job
6. Ensure Trigger only if build is stable is selected E7. nsure the Build other projects block is below the Git Publisher block

Step 10 - Deploying app onto ec2 Instance

General

1. Click Discard old builds and keep the max number of build to 2
2. Click GitHub project and add the HTTP URL of the repository

Office 365 Connector

• Click Restrict where this project can be run, then set it as sparta-ubuntu-node

Source Code Management

• Keep it at None

Build Environment

1. Select Provide Node & npm bin/ folder to PATH
2. Select SSH Agent:

• Select Specific credentials
• Select the SSH key for the EC2 instance (DevOpsStudent in this case)

Build

1. Select Add build step > Execute Shell

2. In command, insert the following code:

   `rm -rf eng99_cicd_jenkins* git clone -b main https://github.com/ali-tm-amin/j_cicd.git

   rsync -avz -e "ssh -o StrictHostKeyChecking=no" app ubuntu@deploy_public_ip:/home/ubuntu/app rsync -avz -e "ssh -o StrictHostKeyChecking=no" environment ubuntu@deploy_public_ip:/home/ubuntu/app

   ssh -A -o "StrictHostKeyChecking=no" ubuntu@deploy_public_ip <<EOF

    # 'kill' all running instances of node.js
    killall npm
   
    # run provisions file for dependencies
    cd /home/ubuntu/app/environment/app
    chmod +x provision.sh
    ./provision.sh
   
    # Install npm for remaining dependencies
    cd /home/ubuntu/app/app
    sudo npm install
    node seeds/seed.js
   
    # Run the app
    node app.js &
    
    EOF`
   

3. NOTE: the deploy_public_ip will need to be changed each time you re-run the deployment EC2 instance

Step 11 - Provisioning database

General

1. Click Discard old builds and keep the max number of build to 2
2. Click GitHub project and add the HTTP URL of the repository

Office 365 Connector Click Restrict where this project can be run, then set it as sparta-ubuntu-node

Source Code Management

1. Select Git
2. In Repositories:

• Repository URL: insert the SSH URL
• Credentials: select the credential you created earlier Branches to build: set to */dev (dev branch)

Build Environment Select Provide Node & npm bin/ folder to PATH

Post-build Actions

1. First, select Add post-build action > Git Publisher
2. Click Push Only If Build Succeeds
3. In Branches:

• Branch to push: main
• Target remote name: origin

4. Next, select Add post-build action > Build other projects
5. Insert the project name for the deploy job
6. Ensure Trigger only if build is stable is selected E7. nsure the Build other projects block is below the Git Publisher block

Step 12 - EC2 Instance for Deployment

We will deploy our application on an EC2 instance.

1. Create a new EC2 instance
2. Choose Ubuntu Server 16.04 LTS (HVM), SSD Volume Type as the AMI
3. Choose t2.micro as the instance type (the default)
4. On Configure Instance Details:

• Change the VPC to your VPC
• Change subnet to your public subnet
• Enable Auto-assign Public IP

5. Add a tag with the Key as Name and enter an appropriate name as the value
6. Enter a suitable name and description for the Security Group with the following rules:

• SSH (22) with source My IP - allows you to SSH
• SSH (22) with source jenkins_server_ip/32 - allows Jenkins server to SSH
• HTTP (80) with source Anywhere - allow access to the app
• Custom TCP (3000) with source 0.0.0.0/0 - allow access to port 3000

7. Review and Launch
8. Select the existing DevOpsStudent key:pair option for SSH
9. Ensure the public NACL allows SSH (22) with source jenkins_server_ip/32
10. If the Jenkins server updates/reboots, the GitHub webhook, security group and NACL need to be modified

Step 13: Trigger the Builds!

1. Switch to the dev branch
2. Make any change to your repository
3. Add, commit and push your changes to the dev branch
4. A CI build will trigger
5. A merge build will only trigger if the tests in the CI build pass
6. After the merge build, the dev branch will merge with your main branch on GitHub
7. If the deployment build succeeds, the app will be running on its public IP!
8. NOTE: the image will only display if you access port 3000

## Bonus Step: Running in Vagrant

1. Run both the app and database using vagrant up app and vagrant up db respectively on separate terminals
2. SSH into the app using vagrant ssh app
3. Navigate to the /home/ubuntu/ directory (you are placed in /home/vagrant/ by default)
4. Go to the /home/ubuntu/app/app directory and run node seeds/seed.js to populate the database
5. Run npm install for any remaining dependencies
6. Execute node app.js to run the app
7. On a web browser, enter development.local:3000 to show that the app is working
8. The posts page will open with development.local:3000/posts