👀 Views: 61 💬 Answers: 1 📅 Created: 2025-07-24

aws cloudformation nested-stacks YAML

I'm stuck on something that should probably be simple. I've spent hours debugging this and I'm collaborating on a project where This might be a silly question, but I'm trying to deploy an AWS CloudFormation stack that includes several nested stacks... However, I'm getting an 'Invalid Template' behavior when I attempt to create the parent stack. Here’s the snippet of my template where the nested stack is defined: ```yaml Resources: MyParentStack: Type: AWS::CloudFormation::Stack Properties: TemplateURL: https://s3.amazonaws.com/mybucket/my-nested-stack.yaml Parameters: InstanceType: t2.micro KeyName: MyKeyPair ``` I confirmed that the `TemplateURL` is correct and accessible. The nested stack YAML file looks like this: ```yaml Parameters: InstanceType: Type: String KeyName: Type: String Resources: MyEC2Instance: Type: AWS::EC2::Instance Properties: InstanceType: !Ref InstanceType KeyName: !Ref KeyName ``` When I run `aws cloudformation validate-template --template-body file://parent-stack.yaml`, it returns a validation success, but deploying the parent stack gives the behavior. I've also checked the IAM permissions for the S3 bucket where the nested stack is stored and they seem to be correctly configured. I suspect there might be an scenario with the way I'm referencing parameters or something related to the template format. Any pointers on how to debug this further or common pitfalls with nested stacks in CloudFormation? I'm working on a CLI tool that needs to handle this. What am I doing wrong? What's the best practice here? I recently upgraded to Yaml latest. Thanks, I really appreciate it! I've been using Yaml for about a year now. I'm open to any suggestions. I'm using Yaml latest in this project. For context: I'm using Yaml on Debian. Any help would be greatly appreciated! The project is a mobile app built with Yaml.