👀 Views: 6 💬 Answers: 1 📅 Created: 2025-05-31

cloudformation aws nested-stacks YAML

I'm integrating two systems and I'm trying to figure out I've searched everywhere and can't find a clear answer. I'm having trouble with nested stacks in AWS CloudFormation, where the parameters I intend to pass from the parent stack to the child stack do not seem to be recognized. My parent template looks like this: ```yaml AWSTemplateFormatVersion: '2010-09-09' Parameters: Environment: Type: String Default: dev Resources: MyNestedStack: Type: AWS::CloudFormation::Stack Properties: TemplateURL: https://my-bucket.s3.amazonaws.com/mychildtemplate.yaml Parameters: EnvParam: !Ref Environment ``` And in my child template, I'm trying to use that parameter as follows: ```yaml AWSTemplateFormatVersion: '2010-09-09' Parameters: EnvParam: Type: String Resources: MyBucket: Type: AWS::S3::Bucket Properties: BucketName: !Sub "my-bucket-${EnvParam}" ``` When I deploy the parent stack, I end up with the behavior message: `Parameter EnvParam not found in the parameters list.` I have verified that the S3 URL for the child template is correct and that the parameter is defined properly in both templates. I tried changing the parameter names and making sure that they match exactly, but I still get the same behavior. I've also checked the IAM permissions related to CloudFormation and S3 access. Has anyone encountered this scenario with nested stacks? What could be going wrong here, and how can I ensure that parameters are passed correctly between the stacks? Thanks in advance! Am I approaching this the right way? Thanks for taking the time to read this!