Parameters:
  LayerDeleteParam:
    Type: String
    Default: Delete

Resources:
  MyLayer:
    Type: AWS::Serverless::LayerVersion
    Properties:
      ContentUri: s3://bucket/key
      RetentionPolicy: !Ref LayerDeleteParam

  MyLayerWithAName:
    Type: AWS::Serverless::LayerVersion
    Properties:
      ContentUri: s3://bucket/key
      LayerName: DifferentLayerName

  MyFunction:
    Type: AWS::Serverless::Function
    Properties:
      CodeUri: s3://bucket/key
      Handler: app.handler
      Runtime: python3.6
      Layers:
      - !Ref MyLayer

Outputs:
  LayerName:
    Value: !Ref MyLayer
  FunctionName:
    Value: !Ref MyFunction
  FunctionAtt:
    Value: !GetAtt MyFunction.Arn
  LayerSub:
    Value: !Sub ${MyLayer}
  FunctionSub:
    Value: !Sub ${MyFunction}