Can ext proc support modify body according to headers value for each request？

[StarryVae]

Title: Can ext proc support modify body according to headers value？

Description:

for example, the external server want to update body according to the value of header A for each request, can ext proc support now? thanks!

[StarryVae]

cc @tyxia @yanjunxiang-google @stevenzzzz as code owners, thanks.

[yanjunxiang-google]

Yes, the filter can be configured to not send body. When the server sends the header response, it overrides the body processing mode to be "STREAMED": https://github.com/envoyproxy/envoy/blob/64036b42e1581df185d02858d0e5d48b8aaaef97/api/envoy/service/ext_proc/v3/external_processor.proto#L187.

[StarryVae]

@yanjunxiang-google thanks, but maybe i didn't describe the issue clearly, what i want to do is modify body according to the value of header for each request in the ext server, For example, if the value of header foo is a, we set the body to a.

[tyxia]

@StarryVae CONTINUE_AND_REPLACE is probably what you want

[StarryVae]

@tyxia yes, and i want to modify the request json body like {"foo":"bar", "test":"test"......}, if the value of header foo is a, we set the foo in body to a, so the ext server must have the value of request header and body at the same time? How cat i achieve this? thanks!

[tyxia]

send_body_without_waiting_for_header_response enables you to receive both header and body

[StarryVae]

oh, i see it in 1.32, maybe my Envoy version is old, thanks a lot! @tyxia

[StarryVae]

by the way, does ext proc has some ext server examples? thanks!

[StarryVae]

send_body_without_waiting_for_header_response enables you to receive both header and body

and it seems that the ext server has to associate the header and body of the same request?