Method directRequest

modules/caddyhttp/reverseproxy/reverseproxy.go:1402–1426

directRequest modifies only req.URL so that it points to the upstream in the given DialInfo. It must modify ONLY the request URL.

(req *http.Request, di DialInfo)

// directRequest modifies only req.URL so that it points to the upstream
// in the given DialInfo. It must modify ONLY the request URL.
func (h *Handler) directRequest(req *http.Request, di DialInfo) {
	// we need a host, so set the upstream's host address
	reqHost := di.Address

	// if the port equates to the scheme, strip the port because
	// it's weird to make a request like http://example.com:80/.
	if (req.URL.Scheme == "http" && di.Port == "80") ||
		(req.URL.Scheme == "https" && di.Port == "443") {
		reqHost = di.Host
	}

	// add client address to the host to let transport differentiate requests from different clients
	if ppt, ok := h.Transport.(ProxyProtocolTransport); ok && ppt.ProxyProtocolEnabled() {
		if proxyProtocolInfo, ok := caddyhttp.GetVar(req.Context(), proxyProtocolInfoVarKey).(ProxyProtocolInfo); ok {
			// encode the request so it plays well with h2 transport, it's unnecessary for h1 but anyway
			// The issue is that h2 transport will use the address to determine if new connections are needed
			// to roundtrip requests but the without escaping, new connections are constantly created and closed until
			// file descriptors are exhausted.
			// see: https://github.com/caddyserver/caddy/issues/7529
			reqHost = url.QueryEscape(proxyProtocolInfo.AddrPort.String() + "->" + reqHost)
		}
	}

	req.URL.Host = reqHost
}

func (h Handler) provisionUpstream(upstream *Upstream, dynamic bool) {
	// create or get the host representation for this upstream;