[BUGFIX] Retry channel image downloads, continue if it fails (#218)

src/ytdl_sub/downloaders/youtube/channel.py

@@ -228,7 +228,7 @@ class YoutubeChannelDownloader(YoutubeDownloader[YoutubeChannelDownloaderOptions
         self,
         thumbnail_url: str,
         output_thumbnail_path: str,
-    ):
+    ) -> Optional[bool]:
         """
         Downloads a thumbnail and stores it in the output directory
 
@@ -238,12 +238,16 @@ class YoutubeChannelDownloader(YoutubeDownloader[YoutubeChannelDownloaderOptions
             Url of the thumbnail
         output_thumbnail_path:
             Path to store the thumbnail after downloading
+
+        Returns
+        -------
+        True if the thumbnail converted. None if it is missing or failed.
         """
         if not thumbnail_url:
             download_logger.warning("Could not find a thumbnail for %s", self.channel.uid)
-            return
+            return None
 
-        convert_url_thumbnail(
+        return convert_url_thumbnail(
             thumbnail_url=thumbnail_url, output_thumbnail_path=output_thumbnail_path
         )
 
@@ -255,18 +259,22 @@ class YoutubeChannelDownloader(YoutubeDownloader[YoutubeChannelDownloaderOptions
             avatar_thumbnail_name = self.overrides.apply_formatter(
                 self.download_options.channel_avatar_path
             )
-            self._download_thumbnail(
+            if self._download_thumbnail(
                 thumbnail_url=self.channel.avatar_thumbnail_url(),
                 output_thumbnail_path=str(Path(self.working_directory) / avatar_thumbnail_name),
-            )
-            self.save_file(file_name=avatar_thumbnail_name)
+            ):
+                self.save_file(file_name=avatar_thumbnail_name)
+            else:
+                download_logger.warning("Failed to download channel's avatar image")
 
         if self.download_options.channel_banner_path:
             banner_thumbnail_name = self.overrides.apply_formatter(
                 self.download_options.channel_banner_path
             )
-            self._download_thumbnail(
+            if self._download_thumbnail(
                 thumbnail_url=self.channel.banner_thumbnail_url(),
                 output_thumbnail_path=str(Path(self.working_directory) / banner_thumbnail_name),
-            )
-            self.save_file(file_name=banner_thumbnail_name)
+            ):
+                self.save_file(file_name=banner_thumbnail_name)
+            else:
+                download_logger.warning("Failed to download channel's banner image")

src/ytdl_sub/utils/retry.py

@@ -0,0 +1,50 @@
+from time import sleep
+from typing import Any
+from typing import Optional
+from typing import Tuple
+from typing import Type
+
+from ytdl_sub.utils.logger import Logger
+
+logger = Logger.get()
+
+
+def retry(times: int, exceptions: Tuple[Type[Exception], ...], wait_sec: int = 5) -> Optional[Any]:
+    """
+    Retry decorator
+
+    Parameters
+    ----------
+    times
+        Number of attempts to retry
+    exceptions
+        Type of exceptions to retry against
+    wait_sec
+        Number of seconds to wait inbetween retries
+
+    Returns
+    -------
+    Any or None
+        If none, it implies all retries failed
+    """
+
+    def decorator(func):
+        def newfn(*args, **kwargs):
+            attempt = 0
+            while attempt < times:
+                try:
+                    return func(*args, **kwargs)
+                except exceptions:
+                    logger.debug(
+                        "Exception thrown when attempting to run %s, attempt %d of %d",
+                        func.__name__,
+                        attempt + 1,
+                        times,
+                    )
+                    attempt += 1
+                    sleep(wait_sec)
+            return None
+
+        return newfn
+
+    return decorator

src/ytdl_sub/utils/thumbnail.py

@@ -1,8 +1,10 @@
 import tempfile
+from typing import Optional
 from urllib.request import urlopen
 
 from ytdl_sub.entries.entry import Entry
 from ytdl_sub.utils.ffmpeg import FFMPEG
+from ytdl_sub.utils.retry import retry
 
 
 def convert_download_thumbnail(entry: Entry, error_if_not_found: bool = True) -> None:
@@ -32,7 +34,8 @@ def convert_download_thumbnail(entry: Entry, error_if_not_found: bool = True) ->
         FFMPEG.run(["-bitexact", "-i", download_thumbnail_path, download_thumbnail_path_as_jpg])
 
 
-def convert_url_thumbnail(thumbnail_url: str, output_thumbnail_path: str):
+@retry(times=5, exceptions=(Exception,))
+def convert_url_thumbnail(thumbnail_url: str, output_thumbnail_path: str) -> Optional[bool]:
     """
     Downloads and converts a thumbnail from a url into a jpg
 
@@ -42,9 +45,15 @@ def convert_url_thumbnail(thumbnail_url: str, output_thumbnail_path: str):
         URL of the thumbnail
     output_thumbnail_path
         Thumbnail file destination after its converted to jpg
+
+    Returns
+    -------
+    True to indicate it converted the thumbnail from url. None if the retry failed.
     """
     with urlopen(thumbnail_url) as file:
         with tempfile.NamedTemporaryFile() as thumbnail:
             thumbnail.write(file.read())
 
             FFMPEG.run(["-bitexact", "-i", thumbnail.name, output_thumbnail_path, "-bitexact"])
+
+    return True

tests/e2e/youtube/test_channel.py

@@ -1,8 +1,12 @@
+from unittest.mock import patch
+
 import pytest
+from conftest import assert_debug_log
 from e2e.expected_download import assert_expected_downloads
 from e2e.expected_transaction_log import assert_transaction_log_matches
 
 from ytdl_sub.subscriptions.subscription import Subscription
+from ytdl_sub.utils.retry import logger as retry_logger
 
 
 @pytest.fixture
@@ -59,3 +63,20 @@ class TestChannelAsKodiTvShow:
             dry_run=dry_run,
             expected_download_summary_file_name="youtube/test_channel_full.json",
         )
+
+    def test_channel_post_download(self, channel_as_tv_show_config, channel_preset_dict):
+        channel_preset_dict["ytdl_options"]["max_views"] = 1  # no downloads occur
+        full_channel_subscription = Subscription.from_dict(
+            config=channel_as_tv_show_config, preset_name="pz", preset_dict=channel_preset_dict
+        )
+
+        with assert_debug_log(  # Ensure retry debug message is thrown
+            logger=retry_logger,
+            expected_message="Exception thrown when attempting to run %s, attempt %d of %d",
+        ), patch(  # Make sleeps instant
+            "ytdl_sub.utils.retry.sleep"
+        ), patch(  # Mock error when calling urlopen
+            "ytdl_sub.utils.thumbnail.urlopen"
+        ) as mock_urlopen:
+            mock_urlopen.side_effect = [Exception("error")]
+            full_channel_subscription.download(dry_run=True)