Make path-help request forward (#2677)

http/forwarding_test.go

@@ -595,3 +595,33 @@ func TestHTTP_Forwarding_ClientTLS(t *testing.T) {
 		}
 	}
 }
+
+func TestHTTP_Forwarding_HelpOperation(t *testing.T) {
+	handler1 := http.NewServeMux()
+	handler2 := http.NewServeMux()
+	handler3 := http.NewServeMux()
+
+	cores := vault.TestCluster(t, []http.Handler{handler1, handler2, handler3}, &vault.CoreConfig{}, true)
+	for _, core := range cores {
+		defer core.CloseListeners()
+	}
+
+	handler1.Handle("/", Handler(cores[0].Core))
+	handler2.Handle("/", Handler(cores[1].Core))
+	handler3.Handle("/", Handler(cores[2].Core))
+
+	vault.TestWaitActive(t, cores[0].Core)
+
+	testHelp := func(client *api.Client) {
+		help, err := client.Help("auth/token")
+		if err != nil {
+			t.Fatal(err)
+		}
+		if help == nil {
+			t.Fatal("help was nil")
+		}
+	}
+
+	testHelp(cores[0].Client)
+	testHelp(cores[1].Client)
+}

http/help.go

@@ -8,14 +8,18 @@ import (
 )
 
 func wrapHelpHandler(h http.Handler, core *vault.Core) http.Handler {
-	return http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
-		// If the help parameter is not blank, then show the help
+	return http.HandlerFunc(func(writer http.ResponseWriter, req *http.Request) {
+		// If the help parameter is not blank, then show the help. We request
+		// forward because standby nodes do not have mounts and other state.
 		if v := req.URL.Query().Get("help"); v != "" || req.Method == "HELP" {
-			handleHelp(core, w, req)
+			handleRequestForwarding(core,
+				http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+					handleHelp(core, w, r)
+				})).ServeHTTP(writer, req)
 			return
 		}
 
-		h.ServeHTTP(w, req)
+		h.ServeHTTP(writer, req)
 		return
 	})
 }