deletion_policy.yaml

AWSTemplateFormatVersion : "2010-09-09"
Description: "Sample Template"

Parameters:
    S3BucketName:
        Description: Enter S3 bucket name
        Type: String
        MinLength: 3
        MaxLength: 10
        AllowedPattern: "^[A-Za-z0-9_-]*$"

    LambdaFunctionName:
        Description: Enter Lambda function name
        Type: String
        MinLength: 3
        MaxLength: 10
        AllowedPattern: "^[A-Za-z0-9_-]*$"


Resources:
    S3Bucket:
        Type: AWS::S3::Bucket
        DeletionPolicy: Retain
        Properties:
            BucketName: !Join [ '-', [ !Ref S3BucketName, !Ref AWS::StackName, !Ref AWS::Region ] ]

    IAMRole:
        Type: AWS::IAM::Role
        Properties:
            ManagedPolicyArns: 
                - arn:aws:iam::aws:policy/AWSLambdaExecute

            AssumeRolePolicyDocument:
                Version: '2012-10-17'
                Statement:
                - Effect: Allow
                  Principal:
                    Service:
                    - lambda.amazonaws.com
                  Action:
                  - sts:AssumeRole

    LambdaFunction:
        Type: AWS::Lambda::Function
        Properties:
            FunctionName: !Join [ '-', [ !Ref LambdaFunctionName, !Ref AWS::StackName, !Ref AWS::Region ] ]
            Handler: lambda_function.lambda_handler
            Runtime: python3.9
            Role: !GetAtt IAMRole.Arn
            Code:
                ZipFile: |
                  import json
                  def lambda_handler(event, context):
                      print(f"Event: {event}")
                      return {
                            'statusCode': 200,
                            'body': json.dumps('Hello from Lambda!')
                        }