What are CloudFormation parameters and how do I use them?

What are CloudFormation parameters and how do I use them?

CloudFormation parameters allow you to pass values into your CloudFormation templates at runtime, making them more flexible.

Can you give me an example of how to define parameters in a template?

Sure! You can define parameters in the 'Parameters' section of your template like this:

Parameters:
  InstanceType:
    Type: String
    Default: t2.micro
    Description: EC2 instance type

How do I reference these parameters in my resources?

You can reference parameters using the !Ref intrinsic function. For example:

Resources:
  MyEC2Instance:
    Type: AWS::EC2::Instance
    Properties:
      InstanceType: !Ref InstanceType

What if I want to set a default value for a parameter?

You can set a default value in the parameter definition, as shown in the previous example with Default: t2.micro.