`amiIdSsmPath` creates SSM parameter with `DataType: text` instead of `aws:ec2:image`, breaking ASG Instance Refresh

[AndrewChemis]

When using amiIdSsmPath to have Image Builder write the output AMI ID to an SSM parameter, the parameter is created with DataType: text. This breaks Auto Scaling Group Instance Refresh when the Launch Template uses resolve:ssm: syntax, as AWS requires DataType: aws:ec2:image for this use case.

Expected Behavior

When amiIdSsmPath is configured, Image Builder should create the SSM parameter with DataType: aws:ec2:image so it's compatible with Launch Template dynamic AMI resolution and ASG Instance Refresh.

Actual Behavior

The SSM parameter is created with DataType: text, causing Instance Refresh to fail with:

An error occurred (ValidationError) when calling the StartInstanceRefresh operation: 
Unsupported data type. The following parameter data types are supported: aws:ec2:image

Steps to Reproduce

1. Create an Image Pipeline with amiIdSsmPath configured:

const imagePipeline = new ImagePipeline(this, 'image-pipeline', {
  // ... other config
  amiIdSsmPath: '/my/ami/parameter',
  amiIdSsmAccountId: Stack.of(this).account,
  amiIdSsmRegion: Stack.of(this).region,
});

2. Create a Launch Template using the SSM parameter:

const launchTemplate = new LaunchTemplate(this, 'launch-template', {
  machineImage: MachineImage.fromSsmParameter('/my/ami/parameter'),
});

3. Create an ASG with the Launch Template
4. Run the Image Builder pipeline (creates the SSM parameter)
5. Attempt to start an Instance Refresh on the ASG

Workaround

Pre-create the SSM parameter in CDK with the correct data type before Image Builder runs:

new StringParameter(this, 'ami-parameter', {
  parameterName: '/my/ami/parameter',
  stringValue: 'ami-placeholder',
  dataType: ParameterDataType.AWS_EC2_IMAGE,
});

Image Builder will then update only the value, preserving the data type.

Suggested Fix

Add an optional property to configure the SSM parameter data type, or default to aws:ec2:image since the parameter is specifically for AMI IDs:

interface ImagePipelineProps {
  // existing props...
  amiIdSsmPath?: string;
  amiIdSsmDataType?: 'text' | 'aws:ec2:image'; // default to 'aws:ec2:image'
}

Environment

• cdk-image-pipeline version: 0.5.133
• aws-cdk-lib version: 2.218.0
• Node.js version: 24.x

References

• AWS SSM Parameter Data Types
• ASG Instance Refresh with SSM Parameters