validate-template fails to identify AWS::CloudFormation::Stack Properties TemplateBody as invalid

[sparr]

Describe the bug

The following template validates successfully, but then fails during create-stack due to Encountered unsupported property TemplateBody. Other more-obviously-invalid property names like foo produce expected validation failures.

Expected Behavior

Validation failure

Current Behavior

Successful validation

Reproduction Steps

aws cloudformation validate-template --template-body file://thefollowingfile.yaml

AWSTemplateFormatVersion: '2010-09-09'
Resources:
  TestStack:
    Type: AWS::CloudFormation::Stack
    Properties:
      TemplateBody:
        AWSTemplateFormatVersion: '2010-09-09'

Possible Solution

No response

Additional Information/Context

No response

CLI version used

aws-cli/2.14.4

Environment details (OS name and version, etc.)

Python/3.11.6 Darwin/23.1.0 MacOS/14.1

[max-allan-surevine]

I think this is more about missing functionality than the Linter being wrong.

TemplateBody is a documented parameter:
https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-cloudformation-stack.html#cfn-cloudformation-stack-templatebody

Do we need to raise a feature request to get a documented feature to work??? I just wasted a couple of hours trying to make this work, assuming I'd got something else wrong. "It must be right, it's in the docs. Maybe I've got my !Sub wrong or something..."

[sparr]

There's further context in aws-cloudformation/cfn-lint#2975

Apparently TemplateBody is only valid in... some unknown context, and it's not valid when using CFN to define a Stack.

[SlazyHW]

Got the same issue. I want to deploy a cloudformation template using the CLI which creates two sub-stacks. I want to pass the template bodies to both stacks as variables (I extract the *.yaml-files' content and convert it into *.json-syntax) but I get the following error:

"Encountered unsupported property TemplateBody"

Just wasted some hours on trying to get this right. Now I have to change to S3 buckets using the TemplateURL property. Kind of annoying because its clearly part of the documentation.

[max-allan-surevine]

If it's only valid in some undocumented context : Then the issue is with the documentation.

If the documentation does not declare the unknown context then how can the tooling/users know what the context they must use is?

Considering Cfn is an AWS product, it has far too many bugs like this.

[tim-finnigan]

Thanks for reporting this issue and your patience here. Based on what has been discussed, this does appear to be an issue with the underlying ValidateTemplate API and/or documentation. Since service APIs like that are used across SDKs, I'll go ahead and transfer this to our cross-SDK repository. I'll also reach out to the CloudFormation team regarding this issue and will share any updates here. Thanks again. (ref: P129370565)

Update - transferred back to original repository for continued tracking.