yatavm's Introduction

Description

Yet Another Terraform AWS VPC module (yatavm).

Motivation

Most Terraform AWS modules use count to create resources. Sometimes this can cause issues and force to recreate resources when adding or changing vpc elements like nat gateways or routes.
To avoid this, terraform can use for_each statement, which creates keys instead of indexes to define resources.
This terraform module only uses for_each statement to create conditional multielement resources.

Usage

VPC deployment example

module "vpc" {
  name   = "myvpc"
  source = "../"

  aws_region      = "us-west-2" # AWS region where the VPC will be deployed.
  cidr            = "10.0.0.0/16" # cidr of the vpc
  private_subnets = ["10.0.0.0/23", "10.0.2.0/23", "10.0.4.0/23"] # Private Subnets cidr
  public_subnets  = ["10.0.100.0/23", "10.0.102.0/23", "10.0.104.0/23"] # Public Subnets cidr

  # public_inbound_acl_rules   = local.network_acls["public_inbound"] # Optional
  # public_outbound_acl_rules  = local.network_acls["public_outbound"] # Optional
  # private_inbound_acl_rules  = local.network_acls["private_inbound"] # Optional
  # private_outbound_acl_rules = local.network_acls["private_outbound"] # Optional
}

Subnets

This module allows creating up to 1 subnet per each availability zone in the AWS region.
For example, if you deploy a VPC in an AWS region which has 3 AZ, you can define a cidr list between 1 and 3 elements.
The module automatically creates the subnets in different AZ and validates that the number of defined subnets are available in the AWS Region.