Learn how to create a Lambda in CloudFormation

You possibly can create a Lambda in CloudFormation as follows:

Choice 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 operate code right here
              return {
                  'statusCode': 200,
                  'physique': json.dumps('Good day from Lambda!')
              }
      Function: !GetAtt MyLambdaExecutionRole.Arn

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

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

Choice 2 – Embrace 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
      Function: !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 operate named MyLambdaFunction.

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

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

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

Be sure that to regulate the values in accordance with your necessities. After you have outlined this useful resource in your CloudFormation template, you possibly can deploy the template to create the Lambda operate utilizing AWS CloudFormation.