CloudFormation template Metadata syntax - AWS CloudFormation
JSONYAMLMetadata keys

CloudFormation template Metadata syntax

You can use the optional Metadata section to include arbitrary JSON or YAML objects that provide details about the template. For example, you can include template implementation details about specific resources, as shown in the following snippet:

Important

During a stack update, you cannot update the Metadata section by itself. You can update it only when you include changes that add, modify, or delete resources.

Important

CloudFormation does not transform, modify, or redact any information you include in the Metadata section. Because of this, we strongly recommend you do not use this section to store sensitive information, such as passwords or secrets.

JSON

"Metadata" : {
  "Instances" : {"Description" : "Information about the instances"},
  "Databases" : {"Description" : "Information about the databases"}
}

YAML

Metadata:
  Instances:
    Description: "Information about the instances"
  Databases: 
    Description: "Information about the databases"

Metadata keys

Some CloudFormation features retrieve settings or configuration information that you define in the Metadata section. You define this information in the following CloudFormation-specific metadata keys:

AWS::CloudFormation::Init

Defines configuration tasks for the cfn-init helper script. This script is useful for configuring and installing applications on EC2 instances. For more information, see AWS::CloudFormation::Init.

AWS::CloudFormation::Interface

Defines the grouping and ordering of input parameters when they are displayed in the CloudFormation console. By default, the CloudFormation console alphabetically sorts parameters by their logical ID. For more information, see AWS::CloudFormation::Interface.

AWS::CloudFormation::Designer

Describes how your resources are laid out in AWS CloudFormation Designer (Designer). Designer automatically adds this information when you use it to create and update templates. For more information, see Using the old AWS CloudFormation Designer to create templates.