How you can create a Lambda in CloudFormation

You possibly can create a Lambda in CloudFormation as follows:

Possibility 1 – Inline code

Sources:
  MyLambdaFunction:
    Sort: AWS::Lambda::Perform
    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!')
              }
      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 perform.

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

Possibility 2 – Embrace a Zip file of code

Sources:
  MyLambdaFunction:
    Sort: AWS::Lambda::Perform
    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. Sources: This part defines the sources you need to create. On this case, you’re making a Lambda perform named MyLambdaFunction.

2. Sort: AWS::Lambda::Perform: This specifies that you simply 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 setting to 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 ought to be executed when the Lambda perform is invoked.
• Code: Specify the placement of the code to your Lambda perform. On this instance, we’re utilizing code saved in an S3 bucket.
• Function: Present the ARN (Amazon Useful resource Title) of an IAM position that grants vital permissions to the Lambda perform.
  !GetAtt MyLambdaExecutionRole.Arn: This retrieves the ARN of an present IAM position named MyLambdaExecutionRole. You would want to outline this IAM position individually in your CloudFormation template.

Be sure to regulate the values in keeping 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.