Support HTTP header X-Real-Host. v5.11.10

DEVELOPER.md

@@ -749,11 +749,13 @@ but also has extra improvements for we can do more after proxy the API.
 1. If `NAME_LOOKUP` (default is `on`) isn't `off`, try to resolve the candidate from `Host` of HTTP API by SRS Stack.
   1. If access SRS Stack by `localhost` for debugging or run in localhost.
     1. If `PLATFORM_DOCKER` is `off`, such as directly run in host, not in docker, use the private ip of SRS Stack.
-    1. Use `127.0.0.1` for OBS WHIP or native client to access SRS Stack by localhost.
+    1. If not set `CANDIDATE`, use `127.0.0.1` for OBS WHIP or native client to access SRS Stack by localhost.
   1. Use `Host` if it's a valid IP address, for example, to access SRS Stack by public ip address.
   1. Use DNS lookup if `Host` is a domain, for example, to access SRS Stack by domain name.
 1. If no candidate, use docker IP address discovered by SRS. 
 
+> Note: Client can also set the header `X-Real-Host` to set the candidate.
+
 > Note: Never use `host.docker.internal` because it's only available in docker, not in host server.
 
 ## Docker Allocated Ports

platform/candidate.go

@@ -68,6 +68,11 @@ func (v *CandidateWorker) Resolve(host string) (net.IP, error) {
 			return conf.ipv4, nil
 		}
 
+		// If already set CANDIDATE, ignore lo.
+		if os.Getenv("CANDIDATE") != "" {
+			return nil, nil
+		}
+
 		// Return lo for OBS WHIP or native client to access it.
 		return net.IPv4(127, 0, 0, 1), nil
 	}

platform/service.go

@@ -290,21 +290,29 @@ func handleHTTPService(ctx context.Context, handler *http.ServeMux) error {
 
 		// Proxy to SRS RTC API, by /rtc/ prefix.
 		if strings.HasPrefix(r.URL.Path, "/rtc/") {
-			if eip := r.URL.Query().Get("eip"); eip != "" {
+			q := r.URL.Query()
+			if eip := q.Get("eip"); eip != "" {
 				logger.Tf(ctx, "Proxy %v to backend 1985, eip=%v, query is %v",
 					r.URL.Path, eip, r.URL.RawQuery)
 			} else {
+				// Allow test to mock and overwrite the host.
+				host := r.Header.Get("X-Real-Host")
+				if host == "" {
+					host = r.Host
+				}
+
+				// Resolve the host to ip.
 				starttime := time.Now()
-				if ip, err := candidateWorker.Resolve(r.Host); err != nil {
-					logger.Ef(ctx, "Proxy %v to backend 1985, resolve %v failed, cost=%v, err is %v",
-						r.URL.Path, r.Host, time.Now().Sub(starttime), err)
+				if ip, err := candidateWorker.Resolve(host); err != nil {
+					logger.Ef(ctx, "Proxy %v to backend 1985, resolve %v/%v failed, cost=%v, err is %v",
+						r.URL.Path, r.Host, host, time.Now().Sub(starttime), err)
 					ohttp.WriteError(ctx, w, r, err)
 					return
 				} else if ip != nil {
 					eip = ip.String()
 					r.URL.RawQuery += fmt.Sprintf("&eip=%v", eip)
-					logger.Tf(ctx, "Proxy %v to backend 1985, host=%v, resolved ip=%v, cost=%v, query is %v",
-						r.URL.Path, r.Host, eip, time.Now().Sub(starttime), r.URL.RawQuery)
+					logger.Tf(ctx, "Proxy %v to backend 1985, host=%v/%v, resolved ip=%v, cost=%v, query is %v",
+						r.URL.Path, r.Host, host, eip, time.Now().Sub(starttime), r.URL.RawQuery)
 				}
 			}
 

test/system_test.go

@@ -245,7 +245,7 @@ func TestSystem_CandidateByHostIp(t *testing.T) {
 	var answer string
 	if err := NewApi(func(v *testApi) {
 		v.InjectRequest = func(req *http.Request) {
-			req.Host = eip
+			req.Header.Set("X-Real-Host", eip)
 		}
 	}).NoAuth(ctx, fmt.Sprintf("/rtc/v1/whip/?app=live&stream=%v&secret=%v", streamID, pubSecret), offer, &answer); err != nil {
 		r0 = errors.Wrapf(err, "should ok for rtc publish api")