Optional Parameter in CloudFormation

Sometimes you want a CloudFormation Parameter to be optional. Unfortunately a blank Parameter contains an empty string. If you pass this empty string to e.g. the KeyName Property of an EC2 Instance or Launch Configuration you end up with a validation error. Imagine the following CloudFormation template: { "AWSTemplateFormatVersion": "2010-09-09", "Description": "Optional Parameters in CloudFormation: Problem", "Parameters": { "KeyName": { "Description": "Provides the name of the...

Amazon Web Services in Action

Amazon Web Services in Action introduces you to computing, storing, and networking in the AWS cloud.

Customer Reviews:

Subscribe to free monthly updates.

One subscriber wins our book AWS in Action every month.

Subscribe for free