Reports

Answer

This error occurs when the Serverless Framework (or an integrated tool like AWS SAM) cannot resolve a CloudFormation stack name. Here’s how to fix it:

1. Ensure `service` and `stage` Are Properly Configured

Add stage under the provider in serverless.yml. The stack name is auto-generated as ${service}-${stage}:

service: py-events
provider:
  name: aws
  stage: dev  # 👈 Required for stack name resolution
  region: us-east-1  # Optional but recommended

2. Explicitly Define the Stack Name (Optional)

Override the default stack name in serverless.yml:

provider:
  name: aws
  stackName: py-events-${sls:stage}  # e.g., "py-events-dev"

3. Remove Conflicting SAM Files (If Not Using SAM)

If you’re not using AWS SAM:

Delete template.yaml (SAM’s config file).
Remove samconfig.toml (if present).

The Serverless Framework will then use its own stack naming logic.

4. If Using AWS SAM

If you are using SAM (e.g., for other resources):

Create/update samconfig.toml in your project root:

version = 0.1
[default.deploy.parameters]
stack_name = "py-events-dev"
region = "us-east-1"

Deploy with SAM instead of sls:

sam deploy --config-file samconfig.toml

Why Did This Happen Suddenly?

SAM Integration Conflict: If a template.yaml or samconfig.toml file was added recently, the Serverless Framework may default to SAM’s deployment logic, which requires explicit stack names.
AWS SDK/CLI Update: A recent update might have changed how SAM and Serverless Framework interact.

Final Fix (Serverless Framework Only)

Ensure serverless.yml has service, stage, and region:

service: py-events
provider:
  name: aws
  stage: dev
  region: us-east-1

Remove SAM-related files (template.yaml, samconfig.toml).
Deploy:
```
sls deploy --stage dev
```

This resolves the stack name ambiguity by forcing the Serverless Framework to use its internal naming convention.

Verify the Fix

After applying the solution, check the AWS CloudFormation console for a stack.

References:

79413309