reverseproxy: Reuse buffered request body even if partially drained

Previous commit only works when the backends don't read any of the body first.

Matthew Holt committed Apr 22, 2024 at 15:22 UTC d93e027e01905406671ed8df295d5e48d16645c2

1 file changed +9

modules/caddyhttp/reverseproxy/reverseproxy.go

@@ -439,6 +439,15 @@ func (h *Handler) ServeHTTP(w http.ResponseWriter, r *http.Request, next caddyht

439 var proxyErr error

440 var retries int

441 for {

442 + // if the request body was buffered (and only the entire body, hence no body

443 + // set to read from after the buffer), make reading from the body idempotent

444 + // and reusable, so if a backend partially or fully reads the body but then

445 + // produces an error, the request can be repeated to the next backend with

446 + // the full body (retries should only happen for idempotent requests) (see #6259)

447 + if reqBodyBuf, ok := r.Body.(bodyReadCloser); ok && reqBodyBuf.body == nil {

448 + r.Body = io.NopCloser(bytes.NewReader(reqBodyBuf.buf.Bytes()))

449 + }

450 +

451 var done bool

452 done, proxyErr = h.proxyLoopIteration(clonedReq, r, w, proxyErr, start, retries, repl, reqHeader, reqHost, next)

453 if done {