What Else to Have in Mind

Progress checklist

Default AWS region confirmed and set in CLI and Terraform
Terraform state strategy understood (local for this walkthrough)
Cost expectations noted and billing alert configured
Teardown approach understood (terraform destroy)

Before creating any infrastructure, take five minutes to confirm a few things that affect every step that follows. These aren’t “nice to have” — a wrong region or forgotten teardown can cause confusing errors or unexpected charges.

Region

Use one AWS region for the entire walkthrough. Every resource — VPC, subnets, EKS cluster, node groups, IAM roles — must be in the same region. Mixing regions causes routing issues and authentication failures.

How to set the default region:

For IAM user credentials (aws configure):

aws configure set region ap-southeast-6

For SSO (set it in your profile config, e.g. ~/.aws/config):

[profile eks-walkthrough]
sso_start_url = https://d-xxxxxxxxxx.awsapps.com/start
sso_region = ap-southeast-6
sso_account_id = 123456789012
sso_role_name = AdministratorAccess
region = ap-southeast-6
output = json

Terraform reads the region from the AWS provider config or from the AWS_REGION environment variable:

export AWS_REGION=ap-southeast-6

Or set it in terraform.tfvars in the Terraform repo (the repo’s README explains how).

This walkthrough uses: ap-southeast-6 (AWS Asia Pacific — New Zealand).

Terraform state

This walkthrough uses local state — Terraform writes terraform.tfstate to the directory where you run commands. This is the simplest setup and works fine for a solo walkthrough.

Why local state is fine here:

You’re the only person running Terraform
The state file lives in the cloned repo directory on your machine
No S3 bucket or DynamoDB table to set up

When to move to remote state (later):

If you continue using this setup for real workloads, or if multiple people or CI need to run Terraform, switch to a remote backend. A common pattern for AWS:

terraform {
  backend "s3" {
    bucket         = "my-terraform-state"
    key            = "eks/terraform.tfstate"
    region         = "ap-southeast-6"
    dynamodb_table = "terraform-state-lock"
  }
}

This is not required for the walkthrough. A later batch may revisit remote state if you productionise.

Cost

The resources created in this walkthrough are not free tier. Approximate cost while running:

Resource	Approximate cost
EKS control plane	~$0.10 / hour
NAT Gateway	~$0.045 / hour + data transfer
EC2 node group (2× t3.medium)	~$0.08 / hour per node
Total (rough estimate)	~$5–10 / day

Always run terraform destroy when you finish a session. EKS, NAT gateways, and nodes continue to bill while running — even if you’re not using them. Check the AWS Billing console if unsure what’s running.

cd ~/workspace/aws-eks-terraform/walkthrough
terraform destroy

To avoid surprise charges:

Set a billing alert (covered in the AWS Account step)
Run terraform destroy at the end of each session
Check the EC2 and EKS dashboards in the Console after destroying to confirm nothing is left running

You’re ready

Prerequisites are complete. Continue to the Networking batch to build the VPC that the EKS cluster will run inside.