AWS cloudformation EC2 YAML parameters

params.yaml

AWSTemplateFormatVersion: 2010-09-09
Description: Create a basic Amazon Linux Server with security group in existing VPC and subnet
Parameters:
  KeyName:
    Description: Key Pair name
    Type: 'AWS::EC2::KeyPair::KeyName'
    Default: keyPair
  VPC:
    Description: Select a VPC
    Type: 'AWS::EC2::VPC::Id'
  Subnet:
    Description: Select a subnet from the VPC
    Type: 'AWS::EC2::Subnet::Id'
  InstanceType:
    Description: Select one of the instance types
    Type: String
    Default: t2.micro
    AllowedValues:
      - t2.micro
      - t2.small
      - t2.medium
  Name:
    Description: The name of the instance
    Type: String