This document contains information about the Lambda service supported in Handel. This Handel service provisions an Lambda function. You can reference this function in other services as an event consumer, which will invoke the function when events occur.

Service Limitations

The following Lambda features are not currently supported in this service:

  • Encrypting environment variables with KMS keys


Parameter Type Required Default Description
type string Yes   This must always be lambda for this service type.
path_to_code string Yes   The location of your code to upload to Lambda. This can be a directory (which will be zipped up) or a single file (such as a deployable Java WAR file or pre-existing zip file)
handler string Yes   The handler function in your code that is the entry-point to the Lambda.
runtime string Yes   The Lambda runtime that will execute your code
description string No Handel-created function The configuration description of your function
memory number No 128 The amount of memory to allocate for your function
timeout number No 3 The timeout in seconds for your function. Max 300
vpc boolean No false If true, the lambda will be deployed inside your VPC. Inside your VPC, it will be able to communicate with resources like RDS databases and ElastiCache clusters.
environment_variables EnvironmentVariables No   Any environment variables you want to inject into your code.
tags Resource Tags No   Any tags you want to apply to your Lambda


The EnvironmentVariables element is defined by the following schema:

  <YOUR_ENV_NAME>: <your_env_value>

<YOUR_ENV_NAME> is a string that will be the name of the injected environment variable. <your_env_value> is its value. You may specify an arbitrary number of environment variables in this section.

Example Handel File

version: 1

name: my-lambda

      type: lambda
      path_to_code: .
      handler: index.handler
      runtime: nodejs6.10
        MY_ENV: myEnvValue
        mytag: mytagvalue

Running a scheduled Lambda

To run a scheduled Lambda, you can use this service in conjunction with the CloudWatch Events service. See the Scheduled Lambda on the CloudWatch Events service for details on how to do this.

Depending on this service

The Lambda service outputs the following environment variables:

Environment Variable Description
<SERVICE_NAME>_FUNCTION_NAME The name of the created Lambda function
<SERVICE_NAME>_FUCNTION_ARN The ARN of the created Lambda function

See Environment Variable Names for information about how the service name is included in the environment variable name.

Events produced by this service

The Lambda service does not currently produce events for other Handel services to consume.

Events consumed by this service

The Lambda service can consume events from the following service types:

  • Alexa Skill Kit
  • CloudWatch Events
  • DynamoDB
  • IoT
  • S3
  • SNS