Terraform AWS DNS Zones

A Terraform module for building a public/private DNS pair in AWS.

This consists of:

A public DNS zone
A private DNS zone

Diagram of infrastructure managed by this module

Usage

To use the module, include something like the following in your Terraform
configuration:

module "dns-zones" {
  source  = "infrablocks/dns-zones/aws"
  version = "2.0.0"
  domain_name         = "example.com"
  private_domain_name = "example.net"
  # Default VPC
  private_zone_vpc_id     = "vpc-6e12c307"
  private_zone_vpc_region = "us-east-2"
}

See the
Terraform registry entry
for more details.

Inputs

Name	Description	Default	Required
`domain_name`	The domain name for the public DNS zone.	-	Yes
`private_domain_name`	The domain name for the private DNS zone.	-	Yes
`private_zone_vpc_id`	The VPC to attach the private DNS zone to.	-	Yes
`private_zone_vpc_region`	The region for the VPC.	-	Yes

Outputs

Name	Description
`public_zone_id`	The ID of the created public zone.
`public_zone_name_servers`	The name servers of the created public zone.
`private_zone_id`	The ID of the created private zone.
`private_zone_name_servers`	The name servers of the created private zone.

Compatibility

This module is compatible with Terraform versions greater than or equal to
Terraform 1.0 and Terraform AWS provider versions greater than or equal to 3.29.

Development

Machine Requirements

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

Mac OS X Setup

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

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

Common Tasks

Generating an SSH key pair

To generate an SSH key pair:

ssh-keygen -m PEM -t rsa -b 4096 -C integration-test@example.com -N '' -f config/secrets/keys/bastion/ssh

Generating a self-signed certificate

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

Managing CircleCI keys

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>"

Contributing

Bug reports and pull requests are welcome on GitHub at
https://github.com/infrablocks/terraform-aws-dns-zones. 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.

License

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