bun-lambda-with-authorizer

Use bun lambda runtime with Authorizer function using a local fork of bun, using cloudformation as a base for the definition of the resources.

⚠️ this project is an example of what you need to do to make authorizer work, and requires changing the runtime code the build process is just me playing with bun feel free to change to something more common ⚠️

Some Things to have in mind

1. I open an issue in bun requesting this change.
2. this project is an example of the code working.
3. majority of the tests were made locally using SAM.

What you need to make this work

• Docker
• SAM
• Bun

main functions are defined in functions/ folder but were built for use in the template.

Important

• you need to run sam init in the root folder and specify 1 - AWS Quick Start Templates with the template location template.yaml.
• you need to add the bun runtime from bun/packages/bun-lambda/bun to ./bun-layer.

Env

you can define whatever you need in .env file

Scripts

some useful scripts to run the project

• bun start
• bun build
• bun deploy
• bun release

Test the lambda

just call the api from your local with the correct authorizer method:

run:

  bun run build && bun run start

make sure you're running docker

then:

curl --header "Authorization: Bearer valid-token" \
  --request POST \
  http://<api-gateway-endpoint>/baselambda 

Changes made in the runtime

  bun-layer/runtime.ts # this is a copy from packages/bun-lambda/runtime.ts

the main issue with the runtime with the authorizer is the default authorizer function needs to return a policy as an object and not as a response as is responded today in the fetch api: example

the solution to support this:

1. add types for the response AuthorizerResultContext, APIGatewayAuthorizerResult.
2. Extend fetch API to support those types.
3. check in #acceptRequest if the request has event.event?.methodArn this means the function is an authorizer.
4. create a new handler for this kind of request authorizerFetch this response the need it policy.

I ❤️ Bun