seanhess / aws-lambda-haskell-runtime-wai

Seamlessly deploy your existing Wai application on AWS Lambda.

aws-lambda-haskell-runtime-wai

Quick start

1. Set up your project to use AWS Lambda by following the instructions on the aws-lambda-haskell-runtime website.
2. Use the waiHandler function from AWS.Lambda.Wai to convert your wai application to a handler. There are two ways to do this.

-- 1. Pass in the initializeApplicationFunction
-- this will call initializeApplication per each call
handler :: WaiHandler ()
handler = waiHandler initializeApplication

-- Wai application initialization logic
initializeApplication :: IO Application
initializeApplication = ...

-- 2. Store the Application inside your custom context and provide a getter function
-- this will initialize the application once per cold start and keep it alive while the lambda is warm
handler :: WaiHandler MyAppConfig
handler = waiHandler' getWaiApp

data MyAppConfig =
  MyAppConfig
    { getWaiApp :: Application }

For a complete example see theam/aws-lambda-haskell-runtime/tree/master/examples/wai-app