template.yml

AWSTemplateFormatVersion: '2010-09-09'
Transform: AWS::Serverless-2016-10-31
Description: >
  Lambda to start/stop instances and reduce costs.

Parameters:
  Regions:
    Type: String
    Description: Regions which instances are going to be affected
    Default: sa-east-1,us-east-1

Resources:
  LambdaFunction:
    Type: AWS::Serverless::Function
    Properties:
      FunctionName: startstop-instances
      MemorySize: 128
      Timeout: 10
      Environment:
        Variables:
          REGIONS: !Ref Regions
      Policies:
        - Statement:
            - Sid: RDSStartStopPolicy
              Effect: Allow
              Action:
                - rds:DescribeDBInstances
                - rds:StartDBInstance
                - rds:StopDBInstance
              Resource: '*'
      CodeUri: src/
      Handler: lambda_handler.lambda_handler
      Runtime: python3.8
      Events:
        Start:
          Type: Schedule
          Properties:
            Schedule: cron(0 12 ? * MON-FRI *)
            Input: '{"action": "start"}'
        Stop:
          Type: Schedule
          Properties:
            Schedule: cron(0 20 ? * MON-FRI *)
            Input: '{"action": "stop"}'