Using AWS CloudFormation with layers

You can use CloudFormation to create a layer and associate the layer with your Lambda Event Function. The following example template creates a layer named my-lambda-layer and attaches the layer to the Event Function using the Layers property.

In this example, the template specifies the Amazon Resource Name (ARN) of an existing IAM execution role. You can also create a new execution role in the template using the CloudFormation AWS::IAM::Role resource.

Your Event Function doesn't need any special permissions to use layers.

---
Description: CloudFormation Template for Lambda Event Function with Lambda Layer
Resources:
  MyLambdaLayer:
    Type: AWS::Lambda::LayerVersion
    Properties:
      LayerName: my-lambda-layer
      Description: My Lambda Layer
      Content:
        S3Bucket: amzn-s3-demo-bucket
        S3Key: my-layer.zip
      CompatibleRuntimes:
        - python3.9
        - python3.10
        - python3.11

  MyLambdaFunction:
    Type: AWS::Lambda::Function
    Properties:
      FunctionName: my-lambda-function
      Runtime: python3.9
      Handler: index.handler
      Timeout: 10
      Role: arn:aws:iam::111122223333:role/my_lambda_role
      Layers:
        - !Ref MyLambdaLayer

You can also use AWS Serverless Application Model to manage layers. For more information, see Using AWS SAM with layers.