Ensure repodata.json is updated for proxy channels

New version of mamba requests repodata.json.zst first.
The compressed files are created locally when downloading the non compressed version.
Quetz should always check if the repodata.json file needs to be re-downloaded
so that all files stay consistent.

quetz/main.py

@@ -13,6 +13,7 @@
 from concurrent.futures import ThreadPoolExecutor
 from contextlib import contextmanager
 from email.utils import formatdate
+from pathlib import PurePath
 from tempfile import SpooledTemporaryFile, TemporaryFile
 from typing import Awaitable, Callable, List, Optional, Tuple, Type
 
@@ -1818,12 +1819,20 @@ def serve_path(
  repository = RemoteRepository(channel.mirror_channel_url, session)
  if not pkgstore.file_exists(channel.name, path):
  download_remote_file(repository, pkgstore, channel.name, path)
- elif path.endswith(".json"):
+ elif path.endswith((".json", ".json.bz2", ".json.gz", ".json.zst")):
  # repodata.json and current_repodata.json are cached locally
  # for channel.ttl seconds
- _, fmtime, _ = pkgstore.get_filemetadata(channel.name, path)
+ # if one of the compressed file is requested, we check and download
+ # the non compressed version if needed
+ # (compressed files are created locally and should all have the same fmtime)
+ suffix = PurePath(path).suffix
+ if suffix == ".json":
+ json_path = path
+ else:
+ json_path = path[: -len(suffix)]
+ _, fmtime, _ = pkgstore.get_filemetadata(channel.name, json_path)
  if time.time() - fmtime >= channel.ttl:
- download_remote_file(repository, pkgstore, channel.name, path)
+ download_remote_file(repository, pkgstore, channel.name, json_path)
 
  if (
  is_package_request or pkgstore.kind == "LocalStore"