How to update content-length header after modifying response body via setBuffer(WasmBufferType::HttpResponseBody) ?

[orangetangerine]

Hi, I have a json response like {"foo": "bar"}. It's content-length is 14
I added a wasm to wrap the json response to sth like {"code": 0, "err": "", data: {"foo": "bar"}}. It's content-length is 44.
I tried calling addResponseHeader("content-length", "44") and replaceResponseHeader("content-length", "44") in onResponseBody. Neither worked. And curl complains: curl: (18) transfer closed with 30 bytes remaining to read`.

How can I update content-length after response body is modified?
Thanks.

[PiotrSikora]

No, you cannot update headers after modifying resposne body, since headers are already sent to the client.

However, you don't really need the Content-Length header, and you can safely remove it before modifying the body.

[orangetangerine]

Thanks!