Using Amazon CloudFormation with layers - Amazon Lambda
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Using Amazon CloudFormation with layers

You can use Amazon CloudFormation to create a layer and associate the layer with your Lambda function. The following example template creates a layer named my-lambda-layer and attaches the layer to the Lambda 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 Amazon CloudFormation AWS::IAM::Role resource.

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

---
Description: CloudFormation Template for Lambda 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