11. CF Metadata

It’s an optional section to include arbitrary YAML. For example:

Metadata:
  Instances:
    Descrption: "Information about the instances."
  Databases:
    Descrption: "Information about the databases."

There are four special keys:

• AWS::CloudFormation::Designer: describes how the resources are laid out in your template. This is automatically added by CF Designer.
• AWS::CloudFormation::Interface: defines grouping and ordering of input parameters when they’re displayed in the AWS Console.
• AWS::CloudFormation::Authentication: used to specify authentication credentials for files or sources that you specify in the next item.
• AWS::CloudFormation::Init: define configurations tasks for cfn-init.

Define grouping and ordering of input parameters. It looks like this:

Metadata:
  AWS::CloudFormation::Interface:
    ParameterGroups:
      - Label:
          default: "Network configurations"
        Parameters:
          - parameter1
          - parameter2
      - Label:
          default: "Lambda configurations"
        Parameters:
          - parameter3
    ParameterLabels:
      SubnetID:
        default: "Which subnet should this be deployed to?"

This allows us to give a group of parameters a label to make the template more clear.