Correctly processing proxy request to avoid abortHandler panic (fixes a…

…erokube#598)

.travis.yml

@@ -2,7 +2,7 @@ sudo: required
 language: go
 
 go:
-  - 1.11.x
+  - 1.11.1
 
 services:
   - docker

selenoid.go

@@ -403,7 +403,10 @@ func generateRandomFileName(extension string) string {
 
 func proxy(w http.ResponseWriter, r *http.Request) {
 	done := make(chan func())
-	go func(w http.ResponseWriter, r *http.Request) {
+	go func() {
+		(<-done)()
+	}()
+	func(w http.ResponseWriter, r *http.Request) {
 		cancel := func() {}
 		defer func() {
 			done <- cancel
@@ -447,7 +450,6 @@ func proxy(w http.ResponseWriter, r *http.Request) {
 			},
 		}).ServeHTTP(w, r)
 	}(w, r)
-	go (<-done)()
 }
 
 func reverseProxy(hostFn func(sess *session.Session) string, status string) func(http.ResponseWriter, *http.Request) {

selenoid_test.go

@@ -354,6 +354,23 @@ func TestProxySession(t *testing.T) {
 	queue.Release()
 }
 
+func TestProxySessionPanicOnAbortHandler(t *testing.T) {
+
+	manager = &HTTPTest{Handler: Selenium()}
+
+	resp, err := http.Post(With(srv.URL).Path("/wd/hub/session"), "", bytes.NewReader([]byte("{}")))
+	AssertThat(t, err, Is{nil})
+	var sess map[string]string
+	AssertThat(t, resp, AllOf{Code{http.StatusOK}, IsJson{&sess}})
+
+	req, _ := http.NewRequest(http.MethodGet, With(srv.URL).Path(fmt.Sprintf("/wd/hub/session/%s/url?abort-handler=true", sess["sessionId"])), nil)
+	resp, err = http.DefaultClient.Do(req)
+	AssertThat(t, err, Not{nil})
+
+	sessions.Remove(sess["sessionId"])
+	queue.Release()
+}
+
 func TestSessionDeleted(t *testing.T) {
 	canceled := false
 	ch := make(chan bool)

utils_test.go

@@ -10,6 +10,7 @@ import (
 	"net/http"
 	"net/http/httptest"
 	"net/url"
+	"strconv"
 	"strings"
 	"sync"
 
@@ -121,6 +122,13 @@ func Selenium() http.Handler {
 			http.Error(w, "Session not found", http.StatusNotFound)
 			return
 		}
+		if r.FormValue("abort-handler") != "" {
+			out := "this call was relayed by the reverse proxy"
+			// Setting wrong Content-Length leads to abort handler error
+			w.Header().Add("Content-Length", strconv.Itoa(2*len(out)))
+			fmt.Fprintln(w, out)
+			return
+		}
 		d, _ := time.ParseDuration(r.FormValue("timeout"))
 		if r.Method != http.MethodDelete {
 			<-time.After(d)