Failed to deploy SAM application with reason of Template error: instance of Fn::GetAtt references undefined resource HelloWorldFunctionRole

Desktop (please complete the following information):

• OS: Window 10
• VS Code version: 1.49.0(User setup)
• AWS Toolkit extension version: AWS 1.13.0

Question

I want to deploy my HelloWorldFunction template(Generate by Hello World basic app) , I done the following:

1. Ctrl + Shift + P
2. AWS: Deploy SAM aplication
3. choose template.yaml
4. Select region
5. Enter name for S3 bucket created
6. Enter name of stack

Then I get this error when deploy:

Error: Error with child process: Error: Failed to create changeset for the stack: my-stack, ex: Waiter ChangeSetCreateComplete failed: Waiter encountered a terminal failure state Status: FAILED. 
Reason: Template error: instance of Fn::GetAtt references undefined resource HelloWorldFunctionRole
Deploy failed

It said undefined resource for HelloWorldFunctionRole. But I already stated the Role Arn in my HelloWorldFunction.

Here is my template.yaml:

AWSTemplateFormatVersion: "2010-09-09"
Transform: AWS::Serverless-2016-10-31
Description: >
  MyLambda

  Sample SAM Template for MyLambda

# More info about Globals: https://github.com/awslabs/serverless-application-model/blob/master/docs/globals.rst
Globals:
  Function:
    Timeout: 3

Resources:
  HelloWorldFunction:
    Type: AWS::Serverless::Function # More info about Function Resource: https://github.com/awslabs/serverless-application-model/blob/master/versions/2016-10-31.md#awsserverlessfunction
    Properties:
      CodeUri: hello_world/
      Handler: app.lambda_handler
      Runtime: python3.8
      Role: HERE I set the role arn that I created in AWS console  ** Here is what I add 
      Events:
        HelloWorld:
          Type: Api # More info about API Event Source: https://github.com/awslabs/serverless-application-model/blob/master/versions/2016-10-31.md#api
          Properties:
            Path: /hello
            Method: get

Outputs:
  # ServerlessRestApi is an implicit API created out of Events key under Serverless::Function
  # Find out more about other implicit resources you can reference within SAM
  # https://github.com/awslabs/serverless-application-model/blob/master/docs/internals/generated_resources.rst#api
  HelloWorldApi:
    Description: "API Gateway endpoint URL for Prod stage for Hello World function"
    Value: !Sub "https://${ServerlessRestApi}.execute-api.${AWS::Region}.amazonaws.com/Prod/hello/"
  HelloWorldFunction:
    Description: "Hello World Lambda Function ARN"
    Value: !GetAtt HelloWorldFunction.Arn
  HelloWorldFunctionIamRole:
    Description: "Implicit IAM Role created for Hello World function"
    Value: !GetAtt HelloWorldFunctionRole.Arn

All the above code is generated by AWS SAM Hello World template, I just add the Role Arn value in the field under Runtime as u see above…

What I have done:

1. Created a role in AWS IAM Management Console.
2. Attach policy as LambdaBasicExecutionPolicy for the role
3. Copy Role Arn value to template.yaml as shown above

Then when deploy, I get the error as mention above.

Please give some guidance, don’t know what I missing out so far.

[bryceitoc9]

Hi @kenchoong

Could you try deleting the HelloWorldFunctionIamRole from the Output section? SAM autogenerates a role, I believe using those parameters. Removing this should let you manually set a role.

[kenchoong]

hey @bryceitoc9 ,thanks for the guidance.

It works now after delete HelloWorldFunctionIamRole from Output.

Thank you very much