a. 'Master-Server' will have Java, Jenkins, Maven, Docker, Ansible, & Trivy packages
b. 'Node-Server' will have Docker, Kubeadm & Kubernetes packages

 <Commands to run in 'Node-Server'>
 sudo su -
 passwd ec2-user                         # (set password)
 vi /etc/ssh/sshd_config                 # (Allow 'PermitRootLogin yes' & allow 'PasswordAuthentication yes')
 service sshd restart

 <Commands to run in 'Master-Server'>
 ssh-keygen                              # (this will generate ssh key, press enter when prompted)
 ssh-copy-id ec2-user@<Node_Private_IP>  # (enter 'yes' when prompted & enter the Node's ec2-user password when prompted)

 (Manage Jenkins --> Credentials --> System --> Global credentials)

a. Dockerhub credentials - username & password (Use 'secret text' & save them separately)
b. K8s server username with private key (Use 'SSH Username with private key')
c. Add Github username & token (Generate Github token & save as 'secret key' in Jenkins server)
    (Github: Github settings --> Developer settings --> Personal Token classic --> Generate)
d. Dockerhub token (optional) (Generate token & save as 'secret key')
    (Dockerhub: Account --> Settings --> Security --> Generate token & copy it)

 (Manage Jenkins --> Plugins --> Available plugins --> 'ssh agent' --> Install)
 (This plugin is required to generate ssh agent syntax using pipeline syntax generator)

 Run the pipeline

 a. Enter the 'Pipeline name', 'Project Name' & 'Node-Server' Private IP under the environment variables section
 b. Run the pipeline
 c. Access the content from the browser using <Node_Server_Public_IP>:<NodePort_No>

 a. Automate the CD pipeline after CI pipeline is built successfully
    (CD-pipeline --> Configure --> Build Triggers --> Projects to watch (CI-pipeline) --> 
    Trigger only if build is stable --> Save)
 b. Automate CI pipeline if any changes are pushed to Github
    (Webhook will be created in Github & trigger will be created in Jenkins)
    Jenkins --> Configure --> Build triggers --> 'Github hook trigger for GitSCM polling' --> Save
    Jenkins --> <Your_Account> --> Configure --> API Tokens --> <Jenkins-API-Token>
    Github --> <Your-Repo> --> Settings --> Webhooks --> "<Jenkins-url>:8080/github-webhook/"; -->
    Content type: json;     Secret: <Jenkins-API-Token> --> Add Webhook
    (Try making any changes in your code & the pipeline should automatically trigger)

 a. Run the below command in Terraform to destroy the entire infrastructure
    terraform destroy --auto-approve