Notes

This example provisions an S3 bucket against a local AWS sandbox — no AWS account or credentials required. The sandbox is an Atmos emulator component: a container declared in the normal local stack that Atmos starts and stops for you. By default it runs Floci, a free, MIT-licensed AWS emulator and a drop-in replacement for LocalStack Community Edition (which was EOL'd in March 2026).

The emulator is declared once in the local stack (components.emulator.aws, driver floci/aws) and a single aws/emulator identity in atmos.yaml binds every Terraform component to the local/aws instance. The provider-config contributor injects the AWS provider settings (dummy credentials, path-style S3, skip-flags) automatically, so there is no providers.tf and no endpoint configuration to maintain, and no hand-rolled docker-compose.yml.

Usage

Start the sandbox, apply, then tear everything down (a container runtime — Docker or Podman — is the only prerequisite):

atmos emulator up aws -s local         # start the shared local sandbox
atmos terraform apply demo -s dev     # provision the S3 bucket against the emulator
atmos terraform output demo -s dev    # inspect outputs

atmos terraform destroy demo -s dev   # remove the resources
atmos emulator down aws -s local      # stop and remove the sandbox container

atmos emulator list inventories every configured emulator instance, including local/aws when it has not been started; atmos emulator ps shows the running subset. The INSTANCE column is the value an aws/emulator identity targets. Add -s local to scope either command. For raw container-runtime diagnostics, including stale containers from other projects, use --runtime.

Other lifecycle verbs include atmos emulator logs aws -s local.

The atmos test custom command runs the full apply/destroy lifecycle across the dev, staging, and prod stacks.