gruzewski / terraform-integration-tests

[WIP] Terraform AWS Provider Testing Framework

This project aims to investigate the feasibility of testing End-2-End Terraform AWS code without creating any real resources. It connects existing frameworks like Docker, Moto, or Cartography to create a user-friendly testing framework.

Motivation

It is challenging to get Terraform code correct without trial and error. The most common approach involves applying implemented changes in a test or development environment to confirm that the code doesn't contain syntax errors and does what it is supposed to do. This is incredibly challenging for any "take-home" exercises where many companies would like to test candidates' familiarity with Terraform without involving any costs on their side.

Technical Details

The most important part of the framework is Moto. It is a mocking system for the Boto3 library. Moto has the option to start a standalone server. By changing Boto3's and Terraform's AWS endpoint URLs, one can redirect all requests to Moto's server, where they will interact with mocked resources.

Usage

To apply code in mocked AWS environment, run make all. To destroy everything, just run make cleanup.

TODO: Add info about using Cartography.

Using AWS CLI

It is possible to point local AWS CLI tool to Moto's server. It requires installing awscli-plugin-endpoint in the same Python installation as aws cli.

brew install awscli

/opt/homebrew/Cellar/awscli/[AWS_CLI_VERSION]/libexec/bin/pip3 install --no-deps awscli-plugin-endpoint

[plugins]
endpoint = awscli_plugin_endpoint
cli_legacy_plugin_path = "/opt/homebrew/Cellar/awscli/[AWS_CLI_VERSION]/libexec/lib/[PYTHON_VERSION]/site-packages"

[profile local]
region = eu-west-1
output = json
cloudwatch =
    endpoint_url = http://moto:8888/
ec2 =
    endpoint_url = http://moto:8888/
ecs =
    endpoint_url = http://moto:8888/
eks =
    endpoint_url = http://moto:8888/
iam =
    endpoint_url = http://moto:8888/
route53 =
    endpoint_url = http://moto:8888/
s3 =
    endpoint_url = http://moto:8888/
secretsmanager =
    endpoint_url = http://moto:8888/
ssm =
    endpoint_url = http://moto:8888/
sts =
    endpoint_url = http://moto:8888/

aws --region eu-west-1 ec2 describe-images --filters 'Name=name,Values=amazon-*'