Is there an option for lenient parsing of responses? 'Content-length header received in a 204 response. (RFC7230 3.3.2)'

[erlend-axelsson]

I've just encountered an issue while using the S3 delete object rest api provided by Tigris, it seems it returns a 204 response with a content-length header which gun doesn't like.

{error,{stream_error,{stream_error,protocol_error,
                                   'Content-length header received in a 204 response. (RFC7230 3.3.2)'}}}

This seems to be consistent with the official AWS S3 documentation ( https://docs.aws.amazon.com/AmazonS3/latest/API/API_DeleteObject.html#API_DeleteObject_Example_2 ).

           HTTP/1.1 204 NoContent
           x-amz-id-2: LriYPLdmOdAiIfgSm/F1YsViT1LW94/xUQxMsF7xiEb1a0wiIOIxl+zbwZ163pt7
           x-amz-request-id: 0A49CE4060975EAC
           Date: Wed, 12 Oct 2009 17:50:00 GMT
           Content-Length: 0
           Connection: close
           Server: AmazonS3   

As a workaround I can pattern match on this specific error, though that seems a bit fragile. So I was wondering if there is an option which makes gun a bit more lenient with responses.

[essen]

It's not valid HTTP: https://www.rfc-editor.org/rfc/rfc9110.html#section-8.6

A server MUST NOT send a Content-Length header field in any response with a status code of 1xx (Informational) or 204 (No Content).

Gun does not currently have an option for this. Gun is stricter here with HTTP/2+ as the check isn't performed with HTTP/1.1. Perhaps you can use HTTP/1.1 for this specific request for now.

I guess that even if a content-length isn't allowed by HTTP, a content-length of zero is fairly harmless so introducing an option to relax those harmless checks could be a long term solution.

[erlend-axelsson]

Thank you again :), I'll try it out with 1.1 for now, I suspect it's going to the least used "crud" operation on the bucket anyways.

It's a shame that the S3 api doesn't follow the RFC, though I suspect changing it at this point will probably break a bunch of software built on top of it.

https://xkcd.com/1172/

[essen]

Opened #354 for a future relaxed mode.