Running as AWS Lambda Design

Running as AWS Lambda Design (WIP)

Requirements

• Support the AWS Lambda request object
• Support requests routing, similar to express.js routing
• For development purposes, there should be an easy way to call any handler from the command line
• Support request mapping to restful format such as /account or /account/:id
• Standard data structure to return status code.
• Access to header and query string objects both as map

Design

• Use layers to provide the runtime separately from the main Lambda code.

LambdaRequest type

TODO

Runtime layer

• bootstrap - an NGS file, according to what's described in Custom AWS Lambda Runtimes
  • require()s _HANDLER file
  • (UNSURE YET) calls some initializaiton function
  • Enters the request processing loop (curl, call the _HANDLER specified function, etc) as describe in "Processing Tasks" in the document mentioned above.

The deployment package layer

• F handler(req:LambdaRequest)

TODO / Open Issues

• Requests routing
• Easy calling from command line for development / debugging purposes
  • Maybe a way to pass the whole LambdaRequest to the handler function
    • LambdaRequest in this case should have sane defaults so that not everything (all properties) will have to be passed on each call from CLI
  • A way to call the handler multiple times to debug the initialization code / global state / cleanup.

Resources

• New, better way (2018-11)
  • https://aws.amazon.com/about-aws/whats-new/2018/11/aws-lambda-now-supports-custom-runtimes-and-layers/
  • https://docs.aws.amazon.com/lambda/latest/dg/runtimes-custom.html
    • https://docs.aws.amazon.com/lambda/latest/dg/runtimes-walkthrough.html
  • https://docs.aws.amazon.com/lambda/latest/dg/configuration-layers.html
• https://aws.amazon.com/blogs/compute/scripting-languages-for-aws-lambda-running-php-ruby-and-go/