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proxy-wasm / proxy-wasm-cpp-host

WebAssembly for Proxies (C++ host implementation)
Apache License 2.0
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re support the StopIteration status #417

Open wbpcode opened 2 months ago

wbpcode commented 2 months ago

We converted all StopIteration to StopAll at #95.

It make the wasm filter couldn't work in some typically scenarios, for example, custom auth may require to parse body to complete the authentication, but return Continue when calling onRequestHeaders will proxy headers to uptream before we complete the authentication, return StopAll will prohibit the wasm to access body.

mpwarres commented 2 months ago

143 discusses the same (or similar) issue, suggest deduping and reviving the discussion there, unless there is a different aspect to this issue. @wbpcode WDYT?

wbpcode commented 2 months ago

yea, it's the same issue. This is a very important feature for a bunch of filters.

Without it, we even cannot set the content length correctly after mutate the body. It's weird.

PiotrSikora commented 1 month ago

Without it, we even cannot set the content length correctly after mutate the body. It's weird.

You don't need to set Content-Length header. If you plan to mutate body, then you should remove Content-Length header and either set Content-Encoding: chunked yourself or it will be automatically applied by Envoy.

wbpcode commented 1 month ago

Without it, we even cannot set the content length correctly after mutate the body. It's weird.

You don't need to set Content-Length header. If you plan to mutate body, then you should remove Content-Length header and either set Content-Encoding: chunked yourself or it will be automatically applied by Envoy.

It just an example, more usual cases are do something based on the body and change the request headers. Or just need to do some verification based on body and need to stop iteration of header filter chain.

PiotrSikora commented 4 weeks ago

It just an example, more usual cases are do something based on the body and change the request headers. Or just need to do some verification based on body and need to stop iteration of header filter chain.

Agreed. And as you know we're adding support for better control over that in ABI v0.3 (https://github.com/proxy-wasm/spec/issues/63) to address other use cases.

However, I wanted to point out that your example is an anti-pattern and you should never buffer the request/response body in order to set Content-Length header, even when you have StopIternation or similar mechanism.

wbpcode commented 4 weeks ago

It just an example, more usual cases are do something based on the body and change the request headers. Or just need to do some verification based on body and need to stop iteration of header filter chain.

Agreed. And as you know we're adding support for better control over that in ABI v0.3 (https://github.com/proxy-wasm/spec/issues/63) to address other use cases.

However, I wanted to point out that your example is an anti-pattern and you should never buffer the request/response body in order to set Content-Length header, even when you have StopIternation or similar mechanism.

Yeah, basically we will remove the content length directly to force Envoy to used the chunked way in practices. I will update the description to avoid misdirecting others.