create a Lambda in CloudFormation

You’ll be able to create a Lambda in CloudFormation as follows:

Possibility 1 – Inline code

Assets:
  MyLambdaFunction:
    Sort: AWS::Lambda::Operate
    Properties:
      FunctionName: MyLambdaFunction
      Runtime: python3.8
      Handler: index.lambda_handler
      Code:
        ZipFile: |
          import json

          def lambda_handler(occasion, context):
              # Your Lambda perform code right here
              return {
                  'statusCode': 200,
                  'physique': json.dumps('Hey from Lambda!')
              }
      Position: !GetAtt MyLambdaExecutionRole.Arn

On this instance, as an alternative of specifying the S3Bucket and S3Key properties below the Code part, you employ the ZipFile property to supply the precise code as a multiline string. The code is written in Python and features a easy Lambda handler perform.

Keep in mind that there’s a restrict to the scale of the CloudFormation template, so in case your Lambda code is massive or advanced, it’s typically beneficial to retailer it in an exterior location like an S3 bucket and reference it utilizing the S3Bucket and S3Key properties.

Possibility 2 – Embody a Zip file of code

Assets:
  MyLambdaFunction:
    Sort: AWS::Lambda::Operate
    Properties:
      FunctionName: MyLambdaFunction
      Runtime: python3.8
      Handler: index.lambda_handler
      Code:
        S3Bucket: my-lambda-bucket
        S3Key: lambda-code.zip
      Position: !GetAtt MyLambdaExecutionRole.Arn

Let’s break down the instance:

1. Assets: This part defines the assets you need to create. On this case, you’re making a Lambda perform named MyLambdaFunction.

2. Sort: AWS::Lambda::Operate: This specifies that you just need to create a Lambda perform useful resource.

3. Properties: Right here, you outline the properties of the Lambda perform.

• FunctionName: This units the identify of the Lambda perform.
• Runtime: Specify the runtime surroundings on your perform. On this instance, we’re utilizing python3.8, however you possibly can select a distinct runtime.
• Handler: Set the identify of the file and the perform throughout the file that needs to be executed when the Lambda perform is invoked.
• Code: Specify the placement of the code on your Lambda perform. On this instance, we’re utilizing code saved in an S3 bucket.
• Position: Present the ARN (Amazon Useful resource Identify) of an IAM function that grants crucial permissions to the Lambda perform.
  !GetAtt MyLambdaExecutionRole.Arn: This retrieves the ARN of an present IAM function named MyLambdaExecutionRole. You would want to outline this IAM function individually in your CloudFormation template.

Make certain to regulate the values in accordance with your necessities. Upon getting outlined this useful resource in your CloudFormation template, you possibly can deploy the template to create the Lambda perform utilizing AWS CloudFormation.