Use the AWS SAM CLI to enable Lambda Insights on an existing Lambda function

Follow these steps to use the AWS SAM AWS CLI to enable Lambda Insights on an existing Lambda function.

If you don't already have the latest version of the AWS SAM CLI installed, you must first install or upgrade it. For more information, see Installing the AWS SAM CLI.

Step 1: Install the layer

To make the Lambda Insights extension available to all of your Lambda functions, add a Layers property to the Globals section of your SAM template with the ARN of the Lambda Insights layer. The example below uses the layer for the initial release of Lambda Insights. For the latest release version of the Lambda Insights extension layer, see Available versions of the Lambda Insights extension.

Globals:
  Function:
    Layers:
      - !Sub "arn:aws:lambda:${AWS::Region}:580247275435:layer:LambdaInsightsExtension:14"

To enable this layer for only a single function, add the Layers property to the function as shown in this example.

Resources:
  MyFunction:
    Type: AWS::Serverless::Function
    Properties:
      Layers:
        - !Sub "arn:aws:lambda:${AWS::Region}:580247275435:layer:LambdaInsightsExtension:14"

Step 2: Add the managed policy

For each function, add the CloudWatchLambdaInsightsExecutionRolePolicy IAM policy.

AWS SAM doesn't support global policies, so you must enable those on each function individually, as shown in this example. For more information about globals, see Globals Section.

Resources:
  MyFunction:
    Type: AWS::Serverless::Function
    Properties:
      Policies:
        - CloudWatchLambdaInsightsExecutionRolePolicy

Invoking locally

The AWS SAM CLI supports Lambda extensions. However, every locally executed invocation resets the runtime environment. Lambda Insights data won’t be available from local invocations because the runtime is restarted without a shutdown event. For more information, see Release 1.6.0 - Add support for local testing of AWS Lambda extensions.

Troubleshooting

To troubleshoot your Lambda Insights installation, add the following environment variable to your Lambda function to enable debug logging.

Resources:
  MyFunction:
    Type: AWS::Serverless::Function
    Properties:
      Environment:
        Variables:
          LAMBDA_INSIGHTS_LOG_LEVEL: info