AWS CloudFormation : AWS Specific Parameter Types

AWS Cloud Formation Parameters.

Parameters section within CloudFormation template is way to gather inputs from user, which can be used within other sections of entire cloudformation script.

Parameter Type

Parameter Type plays a very important, it enable CloudFormation to validate inputs earlier in the stack creation process, thus it is a way cloudformation can validate your input based upon type before even instantiating stack creation.

Here are the valid Parameter types supported by AWS CloudFormation

Type	Details
String	Can be used to validate normal string.
Number	FAn integer or float
List<Number>	RAn array of integers or floats
CommaDelimitedList	HAn array of literal strings that are separated by commas
List<AWS::EC2::SecurityGroup::Id>	Array of security group IDs
AWS::EC2::KeyPair::KeyName	An Amazon EC2 key pair name
AWS::EC2::SecurityGroup::Id	A security group ID
AWS::EC2::Subnet::Id	subnet ID
AWS::EC2::VPC::Id	VPC ID
List<AWS::EC2::VPC::Id	An array of VPC IDs
List<AWS::EC2::Subnet::Id>	An array of subnet IDs

Parameter section Example.

Parameters:

  EnvironmentName:

    Description: Select the environment.

    Type: String

    Default: dev

    AllowedValues:

      - dev

      - prd

  EC2InstanceType:

    Type: String

    Default: t2.micro

    AllowedValues:

        - t2.micro

        - t2.small

  EC2KeyName:

    Description: Select your Key name from List.

    Type: AWS::EC2::KeyPair::KeyName