Baby's First CloudFormation Stack

Globals.yaml

---
AWSTemplateFormatVersion: '2010-09-09'
Description:
  Global configuration that could be used by multiple related stacks
   
# Metadata: # no metadata
 
Parameters:
  Environment:
    Type: String
    Description:
      Stack Environment Prefix.
       
Resources:
  # We need at least one resource. The VPC is the logical one to include here.
  VPC:
    Type: AWS::EC2::VPC
    Properties:
      # The range of ip addresses used in the VPC. Subnets will be inside this.
      # Using the /16 lets me easily have subnets that don't overlap without
      # needing to remember bit masks.
      CidrBlock: 10.0.0.0/16  # 10.0.0.0 -> 10.0.255.255
      EnableDnsSupport: true  # If false, the servers don't seem to get access to DNS at all.
      InstanceTenancy: default
      Tags:
        - Key: Name
          Value: !Sub "${Environment} VPC"
   
Outputs:
  VPC:
    Description: The ID for the Virtual Private Cloud; needed by more or less everything.
    Value: !Ref VPC
    Export:
      Name: !Sub "${Environment}::VPC"

An example 'global' CloudFormation stack, defining resources that we don't want to have to remove and recreate unnecessarily. See https://twasink.net/2019/01/11/ail-babys-first-cloudformation-stack/