aws-cloudformation-vpc

name	aws-cloudformation-vpc
description	Provides AWS CloudFormation patterns for VPC foundations, including subnets, route tables, internet and NAT gateways, endpoints, and reusable outputs. Use when creating a new network baseline, segmenting public and private workloads, or preparing CloudFormation networking stacks for application deployments.
allowed-tools	Read, Write, Bash

AWS CloudFormation VPC Infrastructure

Overview

Build a VPC foundation with CloudFormation that stays readable, reusable, and safe to evolve. Provides a clear subnet and routing model with predictable connectivity for public and private workloads, plus outputs that downstream stacks can consume without duplicating network logic.

Use the references/ files for larger templates and extended service combinations.

When to Use

• Creating a new VPC stack for an application or shared platform
• Adding public and private subnets across one or more Availability Zones
• Wiring internet access, NAT egress, or private endpoints
• Exporting VPC, subnet, route table, and security-group-adjacent identifiers for other stacks
• Preparing reusable infrastructure for ECS, EKS, Lambda, EC2, or RDS stacks

Instructions

1. Start with the address plan

Before writing resources, define:

• VPC CIDR range
• Number of Availability Zones
• Public, private, and isolated subnet ranges
• Which workloads need internet ingress, NAT egress, or only private AWS service access

This prevents route-table sprawl and painful subnet replacement later.

2. Build the core network resources in layers

Create the stack in this order: