AWS-Application loadbalancer 3 Tier Architecture with Terraform

This project utilized terraform modules to provision resources in two availability zones i.e. VPC,ALB, NAT, Multiple EC2 Instances, Security Groups, Public and Private Subnets

Terraform Execution Commands

• Terraform Initialize terraform init
• Observation: Initialized Local Backend, Downloaded the provider plugins (initialized plugins) and Review the folder structure .terraform folder
• Terraform Validate terraform validate
• Observation: If any changes to files, those will come as printed in stdout (those file names will be printed in CLI)
• Terraform Plan terraform plan -> Observation: No changes - Just prints the execution plan
• Terraform Apply terraform apply then approve OR terraform apply -auto-approve
• Terraform Destroy terraform plan destroy then approve OR terraform destroy -auto-approve
• Clean-Up Files: rm -rf .terraform* and rm -rf terraform.tfstate*

Connect to Private EC2 Instances from Bastion EC2 Instance

• Connect with this command ssh -i private-key/cfn-key-1.pem ec2-user@PUBLIC_IP
• Curl Test for Bastion EC2 Instance to Private EC2 Instances curl http://<Private-Instance-1-Private-IP> OR curl http://<Private-Instance-2-Private-IP>
• Connect to Private EC2 Instances from Bastion EC2 Instance ssh -i /tmp/cfn-key-1.pem ec2-user@<Private-Instance-1-Private-IP>
• cd /var/www/html

Observation:

1. list all the files ls -lrta
2. Should find index.html
3. Should find app1 folder
4. Should find app1/index.html file
5. Should find app1/metadata.html file
6. If required verify same for second instance too.
7. Additionally To verify userdata passed to Instance curl http://IP_ADDRESS/latest/user-data UPDATE:Instance_count changed to for-each -> meta-arguments

For Errors

• Booting Error can be accessed through cd /var/log using the root user to view the provisioned resourcesmore cloud-init-output.log