AWSTemplateFormatVersion: 2010-09-09
Transform: AWS::Serverless-2016-10-31
Description: >
  Deploys a lambda function that has the PyMySQL layer and imports PyMySQL. This Lambda works.
  Deploys another lambda function that does not have the PyMySQL layer and imports PyMySQL. This Lambda produces an error.

Resources:
  LambdaRole:
    Type: AWS::IAM::Role
    Properties:
      AssumeRolePolicyDocument:
        Version: 2012-10-17
        Statement:
        - Effect: Allow
          Principal:
            Service:
            - lambda.amazonaws.com
          Action:
          - sts:AssumeRole
      Path: "/"
      ManagedPolicyArns:
        - arn:aws:iam::aws:policy/service-role/AWSLambdaBasicExecutionRole

  PyMySQLLayer:
    Type: AWS::Serverless::LayerVersion
    Properties:
      LayerName: pymysql-layer
      ContentUri: dependencies/
      CompatibleRuntimes:
        - python3.7
        - python3.8

  PyMySQLLayerLambdaFunction:
    Type: AWS::Serverless::Function
    Properties:
      Handler: app.lambda_handler
      Runtime: python3.8
      MemorySize: 128
      Timeout: 3
      Role: !GetAtt LambdaRole.Arn
      CodeUri: src/
      Description: Lambda Function that imports PyMySQL and has the PyMySQL layer
      Layers:
        - !Ref PyMySQLLayer

  PyMySQLNoLayerLambdaFunction:
    Type: AWS::Serverless::Function
    Properties:
      Handler: app.lambda_handler
      Runtime: python3.8
      MemorySize: 128
      Timeout: 3
      Role: !GetAtt LambdaRole.Arn
      CodeUri: src/
      Description: Lambda Function that imports PyMySQL but does not have the PyMySQL layer

Outputs:
  PyMySQLLayerLambdaFunctionName:
    Description: The name of the Lambda Function that has the PyMySQL Layer
    Value: !Ref PyMySQLLayerLambdaFunction
  PyMySQLLayerLambdaFunctionARN:
    Description: The ARN of the Lambda Function that has the PyMySQL Layer
    Value: !GetAtt PyMySQLLayerLambdaFunction.Arn
  PyMySQLNoLayerLambdaFunctionName:
    Description: The name of the Lambda Function that has the PyMySQL Layer
    Value: !Ref PyMySQLNoLayerLambdaFunction
  PyMySQLNoLayerLambdaFunctionARN:
    Description: The ARN of the Lambda Function that has the PyMySQL Layer
    Value: !GetAtt PyMySQLNoLayerLambdaFunction.Arn