AWS Infrastructure Baseline

A small, production‑style AWS web infrastructure built with Terraform, focusing on secure networking, high availability, and team‑friendly remote state.

1. Technical Highlights

• Dynamic AMI Selection: Uses Terraform data sources and filters to always pick the latest Amazon Linux AMI, reducing manual image management and keeping instances up to date.
• Network Isolation: The Auto Scaling Group runs only in private subnets with no public IPs. Traffic from the internet always goes through the Application Load Balancer first.
• Remote state and locking: Uses an S3 backend with DynamoDB locking so multiple people can work safely without corrupting Terraform state.
• Security group lifecycle: Uses standalone aws_vpc_security_group_ingress_rule and egress_rule resources instead of inline blocks to make rules easier to track, review, and change over time.

2. Architecture Overview

• Region: eu-west-2 (configurable via variables).
• High availability: Multi‑AZ deployment across eu-west-2a and eu-west-2b for both public and private subnets.
• Outbound access: Private instances reach the internet via a NAT gateway in a public subnet, so they can update and pull dependencies without being publicly exposed.

Note: This setup is aimed at a dev environment. For production, a second NAT gateway in another AZ is recommended to avoid a single point of failure.

3. Expected Output

4. How to Use

4.1. Configure console and verify

Important: Never share or commit your AWS credentials or config files. Treat them as sensitive.

• Install AWS CLI on your local machine.
• Create AWS credentials in the AWS Console.
• Configure locally using a named profile:

  aws configure --profile dev

• Verify Configuration:

  cat ~/.aws/credentials
  cat ~/.aws/config

Note: This approach is for a dev environment. In production, IAM roles and SSO are to be considered.

4.2. S3 bucket for backend.tf

1. Clone this repo.

git clone https://github.com/RScrafted/aws-infrastructure-baseline.git --progress

2. Create S3 bucket unique-name (one-time step).
3. Create backend-<env>.hcl with your bucket details (from step 2) and run terraform init -backend-config=backend-<env>.hcl.

4.3. Terraform Workflow

1. Initialize:

terraform init -backend-config=backend-dev.hcl

2. Plan & Review:

terraform plan

3. Deploy:

terraform apply

4. Post‑Deployment Checks List all deployed resources:

terraform state list

4.4. Terraform configurations notes

• Update the AWS profile in provider.tf when switching environments (dev/test/prod).
• AWS Provider version is flexible; currently using:

  version = "~> 6.0"

• var.tags is applied in main.tf along with resource names for consistent tagging.

4.5. Cleanup

terraform destroy