srijs/rust-aws-lambda

path and query parameters for gateway

Closed this issue · 7 comments

danielhstahl commented

Is there any way to access the pathParameters and queryParameters attributes from the lambda events for a gateway request?

srijs commented

There isn't currently, but I'm generally not opposed to adding support for it. This could be done through the extensions field on http::Request.

Would you be interested in contributing this feature? I can provide more detailed instructions if that's useful.

LegNeato commented

@srijs Is there a reason why the gateway support is not using the types from https://github.com/srijs/rust-aws-lambda/blob/master/aws_lambda_events/src/generated/apigw.rs ? Would it be helpful to derive some builders and/or some Into on those types?

srijs commented

@LegNeato the main reason was wanting to avoid allocations and copies, e.g. by deserializing the headers directly into http::HeaderMap rather than going via HashMap<String, String>, as well as smaller things like Cow<str> instead of String in cases where the original string was just going to be parsed and ownership wasn't necessary.

I would've loved to just use our autogenerated types, but I wasn't able to figure out how to best approach this. Maybe you have some ideas?

LegNeato commented

@srijs Nope, was just wanting to learn about the decision to give me ideas on how I can generate some more / different options to make them usable!

danielhstahl commented

@srijs I would be interested in contributing and in more detailed instructions :)

srijs commented

So, this is how I would approach it, but I don't have any strong opinions at this point, so please let me know if you had something different in mind. Also let me know if anything is unclear or needs more thought!

(I'd prefer if these changes could be feature flagged under something like extensions -- this will also need to be mapped through on the umbrella crate as gateway-extensions)

Changes to aws_lambda_gateway:

  • Introduce a feature flag extensions
  • Export wrapper structs for path parameters and query parameters (e.g. PathParams and QueryParams) and add some useful getters to those structs
  • Add the new fields to the request event definition ApiGatewayProxyRequestDef in request.rs
  • Modify the ApiGatewayProxyRequestDef::try_into_http_request method to create the parameter structs and insert them into the http::Extensions via http::Request::extensions_mut
  • Extend the tests in request.rs to check for the extensions

Changes to aws_lambda:

  • Add a feature flag gateway-extensions that maps through to aws_lambda_gateway/extensions
  • Re-export PathParams and QueryParams from the gateway module
srijs commented

As we're deprecating this project in favour of https://github.com/awslabs/aws-lambda-rust-runtime, I'm going to close this issue.