A Terraform module and associated submodules for building an API gateway in AWS.

The infrablocks/api-gateway/aws root module:

• has no prerequisite requirements
• consists of:
  • an API Gateway REST API
  • an optional API Gateway REST API policy

Additionally, this module includes 3 submodules:

• infrablocks/api-gateway/aws//modules/deployment for managing an API Gateway stage and deployment of an API Gateway REST API
• infrablocks/api-gateway/aws//modules/domain for configuring a custom domain on an API Gateway REST API
• infrablocks/api-gateway/aws//modules/log_permissions for creating and configuring a logging role for API Gateway

The infrablocks/api-gateway/aws//modules/deployment module:

• requires an existing API Gateway REST API as created by the root module
• consists of:
  • an API Gateway stage
  • an API Gateway deployment

The infrablocks/api-gateway/aws//modules/domain module:

• requires:
  • an existing API Gateway REST API as created by the root module
  • an existing ACM certificate
• consists of:
  • an API Gateway domain
  • an API Gateway base path mapping
  • AWS Route53 records for the domain in each provided hosted zone

The infrablocks/api-gateway/aws//modules/log_permissions module:

• has no prerequisite requirements
• consists of:
  • an IAM role allowing the API Gateway service to manage Cloudwatch logs
  • configuration of the IAM role against the API Gateway service

To use the infrablocks/api-gateway/aws root module, include something like the following in your Terraform configuration:

module "api_gateway" {
  source  = "infrablocks/api-gateway/aws"
  version = "2.0.0"

  region = "eu-west-2"

  component             = "api-gw"
  deployment_identifier = "production"
}

Then to use the infrablocks/api-gateway/aws//modules/deployment submodule:

module "deployment" {
  source  = "infrablocks/api-gateway/aws//modules/deployment"
  version = "2.0.0"

  region = "eu-west-2"

  component             = "api-gw"
  deployment_identifier = "production"

  api_gateway_rest_api_id           = module.api_gateway.api_gateway_rest_api_id
  api_gateway_stage_name            = "default"
  api_gateway_redeployment_triggers = {
    release : 1
  }
}

And to use the infrablocks/api-gateway/aws//modules/domain submodule:

module "domain" {
  source  = "infrablocks/api-gateway/aws//modules/domain"
  version = "2.0.0"

  region = "eu-west-2"

  component             = "api-gw"
  deployment_identifier = "production"

  api_gateway_rest_api_id                 = module.api_gateway.api_gateway_rest_api_id
  api_gateway_stage_name                  = "default"
  api_gateway_domain_name                 = "example.com"
  api_gateway_domain_name_certificate_arn = "arn:aws:acm:eu-west-2:123456789101:certificate/31bd2209-f35b-4668-b48b-324f44fedc7e"

  dns = {
    records : [
      {
        zone_id : "Z0901234DIVFOTMNA324"
      }
    ]
  }
}

The infrablocks/api-gateway/aws//modules/log_permissions module should be used once per account, as follows:

module "domain" {
  source  = "infrablocks/api-gateway/aws//modules/log_permissions"
  version = "2.0.0"
}

See the Terraform registry entry for more details.

This module and all submodules are compatible with Terraform versions greater than or equal to Terraform 1.3 and the Terraform AWS provider 4.0.

In order for the build to run correctly, a few tools will need to be installed on your development machine:

• Ruby (3.1)
• Bundler
• git
• git-crypt
• gnupg
• direnv
• aws-vault

Installing the required tools is best managed by homebrew.

To install homebrew:

ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"

Then, to install the required tools:

# ruby
brew install rbenv
brew install ruby-build
echo 'eval "$(rbenv init - bash)"' >> ~/.bash_profile
echo 'eval "$(rbenv init - zsh)"' >> ~/.zshrc
eval "$(rbenv init -)"
rbenv install 3.1.1
rbenv rehash
rbenv local 3.1.1
gem install bundler

# git, git-crypt, gnupg
brew install git
brew install git-crypt
brew install gnupg

# aws-vault
brew cask install

# direnv
brew install direnv
echo "$(direnv hook bash)" >> ~/.bash_profile
echo "$(direnv hook zsh)" >> ~/.zshrc
eval "$(direnv hook $SHELL)"

direnv allow <repository-directory>

Running the build requires an AWS account and AWS credentials. You are free to configure credentials however you like as long as an access key ID and secret access key are available. These instructions utilise aws-vault which makes credential management easy and secure.

To run the full build, including unit and integration tests, execute:

aws-vault exec <profile> -- ./go

To run the unit tests, execute:

aws-vault exec <profile> -- ./go test:unit

To run the integration tests, execute:

aws-vault exec <profile> -- ./go test:integration

To provision the module prerequisites:

aws-vault exec <profile> -- ./go deployment:prerequisites:provision[<deployment_identifier>]

To provision the module contents:

aws-vault exec <profile> -- ./go deployment:root:provision[<deployment_identifier>]

To destroy the module contents:

aws-vault exec <profile> -- ./go deployment:root:destroy[<deployment_identifier>]

To destroy the module prerequisites:

aws-vault exec <profile> -- ./go deployment:prerequisites:destroy[<deployment_identifier>]

Configuration parameters can be overridden via environment variables. For example, to run the unit tests with a seed of "testing", execute:

SEED=testing aws-vault exec <profile> -- ./go test:unit

When a seed is provided via an environment variable, infrastructure will not be destroyed at the end of test execution. This can be useful during development to avoid lengthy provision and destroy cycles.

To subsequently destroy unit test infrastructure for a given seed:

FORCE_DESTROY=yes SEED=testing aws-vault exec <profile> -- ./go test:unit

To generate an SSH key pair:

ssh-keygen -m PEM -t rsa -b 4096 -C [email protected] -N '' -f config/secrets/keys/bastion/ssh

To generate a self signed certificate:

openssl req -x509 -newkey rsa:4096 -keyout key.pem -out cert.pem -days 365

To decrypt the resulting key:

openssl rsa -in key.pem -out ssl.key

To encrypt a GPG key for use by CircleCI:

openssl aes-256-cbc \
  -e \
  -md sha1 \
  -in ./config/secrets/ci/gpg.private \
  -out ./.circleci/gpg.private.enc \
  -k "<passphrase>"

To check decryption is working correctly:

openssl aes-256-cbc \
  -d \
  -md sha1 \
  -in ./.circleci/gpg.private.enc \
  -k "<passphrase>"

Bug reports and pull requests are welcome on GitHub at https://github.com/infrablocks/terraform-aws-api-gateway. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the Contributor Covenant code of conduct.

The library is available as open source under the terms of the MIT License.