LocalStack Terraform Backend Configuration¶

This configuration demonstrates how to use Terraform with [[LocalStack]] to simulate AWS infrastructure locally^[README.md]. It utilizes a Docker-based workflow to store the tfstate file in a local S3 bucket and manage state locks using a local DynamoDB instance^[README.md].

Prerequisites¶

To implement this setup, ensure the following software is installed on your machine^[README.md]:

docker
docker-compose
tfswitch (for Terraform version management)
Terraform cli
awscli

Docker Network Setup¶

To enable communication between the AWS CLI container and the LocalStack instance, you must create a shared Docker network^[README.md].

Create the network named localstack^[README.md]:
```
docker network create localstack
```

Configure your docker-compose.yml to use this external network^[README.md]:

networks:
  default:
    external:
      name: "localstack"

Initializing LocalStack¶

Once the environment is configured, start the LocalStack container and verify the services^[README.md].

Start Services: Use make up to launch the container^[README.md].
Health Check: Run make health to ensure the dependent services (S3 and DynamoDB) are running^[README.md].

AWS CLI Configuration¶

Since this is a local simulation, the AWS CLI requires a specific configuration pointing to the LocalStack endpoint^[README.md].

Containerized AWS CLI¶

It is recommended to run the AWS CLI v2 via Docker to avoid dependency issues^[README.md].

Alias Command: Set up an alias to simplify commands targeting the LocalStack endpoint^[README.md]:

alias laws='docker run --network localstack -it -v ~/.aws:/root/.aws -e LOCALSTACK_HOSTNAME=localstack amazon/aws-cli --endpoint-url=http://localstack:4566'

Credentials¶

Create a local AWS configuration with dummy credentials. The region is the most critical setting, as credential validation is typically bypassed in this environment^[README.md].

~/.aws/config:

[default]
cli_pager=
output=json
region=ap-southeast-2

~/.aws/credentials:

[default]
aws_access_key_id=test
aws_secret_access_key=test

Provisioning Backend Resources¶

The final step involves using Terraform to create the S3 bucket for state storage and the DynamoDB table for locking^[README.md].

Plan and Apply: Run the standard Terraform workflow commands^[README.md]:
```
make plan
make apply
```

Verification: Use the AWS CLI to confirm the resources were created within LocalStack^[README.md]:

# Verify S3 bucket
laws s3 ls
# Expected Output: 2021-09-05 10:23:23 terraform-state

# Verify DynamoDB table
laws dynamodb list-tables
# Expected Output: { "TableNames": ["terraformlock"] }

Sources¶

README.md

DevOps
[[Infrastructure as Code]]
Terraform
[[LocalStack]]