readthedocs service stack terraform module

This module contains the Terraform configuration for a Read the Docs service stack cluster running on AWS infrastructure. It is composed of alarm, db and web submodules, and builds the following AWS resources:

• an SNS alarm topic
• a DNS CNAME record for the domain
• an SSL cert for the domain
• a Debian 9 EC2 instance for web service
• a PostgreSQL 10 RDS instance for database service
• security groups for web and database access
• cloud watch alarms for system health

Prerequisites

This module uses the aws cli when provisioning alerts. Ensure that it is installed and available in your $PATH.

Usage

Create a module resource with this repository as its source:

module "production" {
  source           = "git::ssh://github.com/mojochao/readthedocs-aws-tf-module.git?ref=1.0.0"
  providers        = {
    aws            = { ... }
  }

  alerts_email     = "readthedocs-alerts@mydomain.com"
  domain_name      = "readthedocs.mydomain.com"
  environment      = "production"
  hosting_zone     = "com.mydomain."
  subnet           = "subnet-deadbeef"
  tags             = { ... }
  vpc              = "vpc-deadbeef"
}

In the example above, only the minimal required inputs are shown. Readthedocs service environments may be further customized with the inputs shown below.

Inputs

This module provides the following inputs, which are forwarded to its alarm, db and web sub-modules.

Name	Description	Type	Default
alerts_email	Email address to send CloudWatch alerts to	string	-
domain_name	Domain name	string	-
environment	Environment name	string	-
hosting_zone	Hosting zone name	string	-
pg_dbname	AWS DB instance database name	string	"readthedocs"
pg_instance_type	AWS DB instance type	string	"db.m4.large"
pg_storage_size_gb	AWS DB instance database size in GB	integer	25
pg_password	AWS DB instance password	string	-
pg_username	AWS DB instance username	string	-
pg_version	PostgreSQL version	string	"10"
region	AWS region name	string	"us-west-2"
ssh_key	AWS SSH key name	string	-
ssl_policy	AWS ssl policy name	string	"ELBSecurityPolicy-TLS-1-2-2017-01"
subnet	AWS subnet id	string	-
tags	AWS resource tags	map	-
vpc	AWS VPC id	string	-
web_instance_ami	AWS Debian AMI to use	string	"ami-0574f98a32ba41dd7"
web_instance_type	AWS EC2 instance type	string	"m5.large"
web_num_workers	Number of gunicorn workers to use.	integer	4
web_volume_size_gb	Data volume size in gigabytes	integer	25

The default AMI used is a Debian 9 AMI for the default us-west-2 region. See https://wiki.debian.org/Cloud/AmazonEC2Image/Stretch for more details.

Outputs

This module itself provides no outputs, however, its alarm, db and web sub-modules do.