[feat] Allow use of proxy for downloading Youtube transscripts

backend/open_webui/apps/retrieval/loaders/youtube.py

@@ -1,7 +1,12 @@
+import logging
+
 from typing import Any, Dict, Generator, List, Optional, Sequence, Union
 from urllib.parse import parse_qs, urlparse
 from langchain_core.documents import Document
+from open_webui.env import SRC_LOG_LEVELS
 
+log = logging.getLogger(__name__)
+log.setLevel(SRC_LOG_LEVELS["RAG"])
 
 ALLOWED_SCHEMES = {"http", "https"}
 ALLOWED_NETLOCS = {
@@ -51,12 +56,14 @@ class YoutubeLoader:
         self,
         video_id: str,
         language: Union[str, Sequence[str]] = "en",
+        proxy_url: Optional[str] = None,
     ):
         """Initialize with YouTube video ID."""
         _video_id = _parse_video_id(video_id)
         self.video_id = _video_id if _video_id is not None else video_id
         self._metadata = {"source": video_id}
         self.language = language
+        self.proxy_url = proxy_url
         if isinstance(language, str):
             self.language = [language]
         else:
@@ -76,10 +83,20 @@ class YoutubeLoader:
                 "Please install it with `pip install youtube-transcript-api`."
             )
 
+        if self.proxy_url:
+            youtube_proxies = {
+                'http': self.proxy_url,
+                'https': self.proxy_url,
+            }
+            # Don't log complete URL because it might contain secrets
+            log.debug(f"Using proxy URL: {self.proxy_url[:14]}...")
+        else:
+            youtube_proxies = None
+
         try:
-            transcript_list = YouTubeTranscriptApi.list_transcripts(self.video_id)
+            transcript_list = YouTubeTranscriptApi.list_transcripts(self.video_id, proxies=youtube_proxies)
         except Exception as e:
-            print(e)
+            log.exception("Loading YouTube transcript failed")
             return []
 
         try: