@studio/lambda

Studio Lambda

🚀 A custom AWS Lambda execution environment for local testing. Runs each Lambda function in it's own process. Integrates with Studio Gateway. Defaults are tailored for apex.

Usage

const Lambda = require('@studio/lambda');

const lambda = Lambda.create();
lambda.invoke('some-lambda', { some: 'event' }, callback);

API

• lambda = Lambda.create([options]): Returns a new Lambda controller for the given options.
  • base_dir: The base directory to use. Defaults to the current working directory.
  • lambda_path: The path to the Lambda function. Replaces ${LAMBDA_NAME} with the Lambda name. Defaults to functions/${LAMBDA_NAME}/.
  • env: An object with environment variables to use. Defaults to an empty object.
  • config_file: A JSON file with additional environment and timeout properties. Defaults to functions/${LAMBDA_NAME}/function.${AWS_PROFILE}.json. Placeholders in the form of ${ENV_VAR} are replaced with the corresponding environment variable.
  • timeout: The default Lambda timeout to use in milliseconds. Defaults to 5 seconds.
  • max_idle: The idle timeout to use in milliseconds. If a function is not invoked for this time, the process gets destroyed. Defaults to 1 hour.
• lambda.invoke(lambda_name, event[, options], callback): Invokes the named Lambda handle function. These options are supported:
  • awsRequestId: The AWS request ID to use in the Lambda context. If a context is given, but one of the above properties is missing, they are added to the context.

Lambda context

Lambda function are invoked with (event, context, callback) where the context has this interface:

• functionName: The name of the Lambda function.
• invokedFunctionArn: The function ARN, build from the AWS_REGION (defaulting to us-east-1), STUDIO_AWS_ACCOUNT (defaulting to 0000) and the Lambda function name.
• memoryLimitInMB: The configured memory limit. This is currently not enforced.
• awsRequestId: The AWS request ID, either from options or generated.
• getRemainingTimeInMillis(): Returns the remaining time until the Lambda function times out.

Debugging Lambda functions

If the environment variable STUDIO_LAMBDA_INSPECT is set to the name of a Lambda function, the node process for that function will be called with --inspect and the timeout value is ignored. This prints a Chrome debugger URL to the console. With this setup in place, you can add debugger statements to place breakpoints.