aws cloudformation creating lamda

 First of all we need to run the following scripts to create our lambda function in python/ 

AWSTemplateFormatVersion: '2010-09-09'

Description: 'AWS Lambda Function with IAM Role and Log Group'

Resources:

  # 1. IAM Role for Lambda Execution

  LambdaExecutionRole:

    Type: AWS::IAM::Role

    Properties:

      AssumeRolePolicyDocument:

        Version: '2012-10-17'

        Statement:

          - Effect: Allow

            Principal:

              Service: [lambda.amazonaws.com]

            Action: ['sts:AssumeRole']

      ManagedPolicyArns:

        - arn:aws:iam::aws:policy/service-role/AWSLambdaBasicExecutionRole

  # 2. CloudWatch Log Group (Prevents logs from being kept forever)

  LambdaLogGroup:

    Type: AWS::Logs::LogGroup

    Properties:

      LogGroupName: !Sub "/aws/lambda/MyCloudFormationFunction"

      RetentionInDays: 7

  # 3. The Lambda Function

  MyLambdaFunction:

    Type: AWS::Lambda::Function

    DependsOn: LambdaLogGroup

    Properties:

      FunctionName: "MyCloudFormationFunction"

      Handler: index.lambda_handler

      Role: !GetAtt LambdaExecutionRole.Arn

      Runtime: python3.12

      Architectures:

        - arm64  # Modern Graviton architecture (cheaper/faster)

      Timeout: 10

      MemorySize: 128

      Code:

        ZipFile: |

          import json

          def lambda_handler(event, context):

              print("Hello from CloudFormation!")

              return {

                  'statusCode': 200,

                  'body': json.dumps('Hello from the Cloud!')

              }

Outputs:

  LambdaArn:

    Value: !GetAtt MyLambdaFunction.Arn

And then we can run the following cli command to deploy this stack

aws cloudformation create-stack \

  --stack-name my-lambda-stack \

  --template-body file://lambda.yaml \

  --capabilities CAPABILITY_IAM \

  --region ap-southeast-2