Implement Lambda API InvokeWithResponseStream

[nakedible-p]

Describe the feature

Lambda currently supports response streaming, but that's used through a separate Invoke API call called InvokeWithResponseStream. https://docs.aws.amazon.com/lambda/latest/api/API_InvokeWithResponseStream.html

Currently there doesn't seem to be any support for this API in the Rust SDK, even though it's supported in the Java, Python and JavaScript SDKs.

Use Case

I need to call Lambda functions that will return more than 6 MB as a response by utilizing the response streaming feature.

Proposed Solution

Implement the API.

Other Information

No response

Acknowledgements

• I may be able to implement this feature request
• This feature might incur a breaking change

A note for the community

Community Note

• Please vote on this issue by adding a 👍 reaction to the original issue to help the community and maintainers prioritize this request
• Please do not leave "+1" or "me too" comments, they generate extra noise for issue followers and do not help prioritize the request
• If you are interested in working on this issue, please leave a comment

[nakedible-p]

The response is application/vnd.amazon.eventstream. Apparently this SDK already has some support for that stream type, but unfortunately it's specialized for the audio stream and not this InvokeWithResponseStream.

aws-sdk-rust/sdk/transcribestreaming/src/event_stream_serde.rs

Line 57 in 963342a

headers.push(::aws_smithy_types::event_stream::Header::new(":content-type", ::aws_smithy_types::event_stream::HeaderValue::String("application/vnd.amazon.eventstream".into())));

[jdisanti]

The code generator already supports event streams for APIs using the Smithy RestJson protocol, so I think this Lambda API would work. We just need to test it and add it to the allow list to let the code generator put it in the actual SDK.

[gautamg795]

Hi, thanks for getting this implemented so quickly! How often do new releases get pushed to crates.io? We'd love to start using this change with Lambda ASAP. I tried to just add the repository as a Cargo dependency but found that the size of this repo makes fetches in CI extremely slow, so we'll wait for an official release to crates.io to get started.

[nakedible-p]

I am not one of the devs, but looking at the release frequency, I doubt it's going to be terribly many days since this is already in pending release: https://github.com/awslabs/aws-sdk-rust/releases

[jdisanti]

It'll go out in one of the daily releases the next time we release smithy-rs, which should be pretty soon.

[jdisanti]

This went out in yesterday's release.

[github-actions]

Comments on closed issues are hard for our team to see.
If you need more assistance, please either tag a team member or open a new issue that references this one.
If you wish to keep having a conversation with other community members under this issue feel free to do so.