fix: collision in cache keys

Author: anatosun

music_assistant/providers/plex/helpers.py

@@ -28,7 +28,10 @@ async def get_libraries(
 
     Returns a dict of Library names in format {'servername / library name':'baseurl'}
     """
-    cache_key = "plex_libraries"
+    # Include server IP and port in cache key to prevent collisions
+    # between multiple Plex servers using the same MyPlex account token
+    cache_key = f"plex_libraries_{local_server_ip}_{local_server_port}"
+    old_cache_key = "plex_libraries"
 
     def _get_libraries() -> list[str]:
         # create a listing of available music libraries on all servers
@@ -54,9 +57,18 @@ def _get_libraries() -> list[str]:
             all_libraries.append(f"{plex_server.friendlyName} / {media_section.title}")
         return all_libraries
 
+    # Check new cache key first
     if cache := await mass.cache.get(cache_key, checksum=auth_token):
         return cast("list[str]", cache)
 
+    # Migration: check old cache key and migrate to new format
+    if old_cache := await mass.cache.get(old_cache_key, checksum=auth_token):
+        # Migrate old cache to new key
+        await mass.cache.set(cache_key, old_cache, checksum=auth_token, expiration=3600)
+        # Delete old cache entry (note: delete doesn't support checksum parameter)
+        await mass.cache.delete(old_cache_key)
+        return cast("list[str]", old_cache)
+
     result = await asyncio.to_thread(_get_libraries)
     # use short expiration for in-memory cache
     await mass.cache.set(cache_key, result, checksum=auth_token, expiration=3600)