THIS IS AN EXAMPLE OF USING TERRAFORM TO DEPLOY INFRASTRUCTURE ON AWS

In this simple project, we will be using terraform to deploy a cluster of 3 webservers or an auto scaling group. We created the front-end and web-cluster modules and use it to deploy.

I. DIRECTORY STRUCTURE

Global <- Contain global resources to share between all staging/prod environment
Modules <- Contain common modules to be reusable and re-deployable for all environments. 
Stage <- Contain sample terraform deployment code that use Modules to create resources for Staging environment

BEFORE CONTINUE, PLEASE SETUP YOUR AWS CREDENTIALS IN THE SYSTEMS

II. HOW TO RUN THIS DEPLOYMENT

1. Create a S3 bucket to store terraform state

This S3 bucket is to store terraform state file. A state file contains information of the infrastructure state that being managed by terraform. Using state file is a way to share current components and state of the infrastructure.

Run:

terraform init ./global/
terraform plan ./global/ (Optional)
terraform apply ./global/

Save the bucket name to use later

2. Create VPC for staging environment

Edit terraform.tf Line bucket = "unique-s3-bucket" <- please replace unique-s3-bucket with your own bucket

From top dir

Run:

terraform init ./stage/vpc/
terraform plan ./stage/vpc/
Terraform apply ./stage/vpc/

The vpc state file contains the newly create vpc information will be stored in the S3 bucket [our-bucket]/stage/vpc/terraform.tfstate

3. Create a front-end

Edit /modules/frontend-app/terraform.tf Line bucket = "unique-s3-bucket" <- please replace unique-s3-bucket with your own bucket

Run

terraform init ./stage/services/front-end/
terraform plan ./stage/services/front-end/
terraform apply ./stage/services/front-end/

It will output the dns name of the LB, if the URL display hello world mean the front-end has been successfully deployed.

Destroy this front-end cluster before continue

terraform destroy ./stage/services/front-end/

4. Create a auto-scaling group

Edit /modules/web-cluster/terraform.tf Line bucket = "unique-s3-bucket" <- please replace unique-s3-bucket with your own bucket

Run

terraform init ./stage/services/web-cluster/
terraform plan ./stage/services/web-cluster/
terraform apply ./stage/services/web-cluster/

It will output the dns name of the LB, if the URL display “hello world” mean the ASG has been successfully deployed. (Might take 1 mins to complete setup)

NOTE:

To deploy to different environment rather than Staging, for e.g PROD; create a new VPC to PROD, save terraform state file to another S3 bucket, use the same modules to deploy but this time, change the vpc_state_file_location to the PROD vpc state file location. You can make further change such as: cluster_name change to PROD, minimum & maximum number of instance. Add your own variable such as instance type, AMI ID…etc