Added timeout and error handling for frpc tunnel (#5731)

* added timeout and error handling for frpc tunnel

* add changeset

* lint

* typing

* spell

* tunneling

* lint

* strip

---------

Co-authored-by: gradio-pr-bot <gradio-pr-bot@users.noreply.github.com>
Co-authored-by: Abubakar Abid <abubakar@huggingface.co>

.changeset/honest-phones-like.md

@@ -0,0 +1,5 @@
+---
+"gradio": patch
+---
+
+fix:Added timeout and error handling for frpc tunnel

gradio/tunneling.py

@@ -4,6 +4,8 @@
 import re
 import stat
 import subprocess
+import sys
+import time
 from pathlib import Path
 from typing import List
 
@@ -24,6 +26,12 @@
 BINARY_FOLDER = Path(__file__).parent
 BINARY_PATH = f"{BINARY_FOLDER / BINARY_FILENAME}"
 
+TUNNEL_TIMEOUT_SECONDS = 30
+TUNNEL_ERROR_MESSAGE = (
+    "Could not create share URL. "
+    "Please check the appended log from frpc for more information:"
+)
+
 
 class Tunnel:
     def __init__(self, remote_host, remote_port, local_host, local_port, share_token):
@@ -88,16 +96,43 @@ def _start_tunnel(self, binary: str) -> str:
             command, stdout=subprocess.PIPE, stderr=subprocess.PIPE
         )
         atexit.register(self.kill)
+        return self._read_url_from_tunnel_stream()
+
+    def _read_url_from_tunnel_stream(self) -> str:
+        start_timestamp = time.time()
+
+        log = []
         url = ""
+
+        def _raise_tunnel_error():
+            log_text = "\n".join(log)
+            print(log_text, file=sys.stderr)
+            raise ValueError(f"{TUNNEL_ERROR_MESSAGE}\n{log_text}")
+
         while url == "":
+            # check for timeout and log
+            if time.time() - start_timestamp >= TUNNEL_TIMEOUT_SECONDS:
+                _raise_tunnel_error()
+
+            assert self.proc is not None
             if self.proc.stdout is None:
                 continue
+
             line = self.proc.stdout.readline()
             line = line.decode("utf-8")
+
+            if line == "":
+                continue
+
+            log.append(line.strip())
+
             if "start proxy success" in line:
                 result = re.search("start proxy success: (.+)\n", line)
                 if result is None:
-                    raise ValueError("Could not create share URL")
+                    _raise_tunnel_error()
                 else:
                     url = result.group(1)
+            elif "login to server failed" in line:
+                _raise_tunnel_error()
+
         return url