User-submitted URLs were passed straight to yt-dlp's generic extractor,
letting the server fetch internal endpoints (cloud metadata, loopback,
RFC1918 hosts). Add a url_guard.validate_url check at every URL ingress
(add, subscribe, and nested playlist recursion) that rejects non-http(s)
schemes and hosts resolving to non-global addresses, while leaving bare
video IDs and search prefixes untouched.
Addresses a full-project review. Backend correctness and availability:
- ytdl: cancel() only SIGKILLs the child's process group when the child
actually became its own group leader, so a race (or failed setpgrp)
can no longer kill the whole server; kill the group on cancel and on
shutdown to avoid orphaned ffmpeg children
- ytdl: dedicated ThreadPoolExecutor for download supervision so active
downloads can't starve extract_info / live probes on the default pool
- ytdl/main/subscriptions: route fire-and-forget tasks through a
bg_tasks helper that keeps a strong ref and logs failures
- subscriptions: run flat-playlist extraction in an executor and check
feeds with bounded concurrency so one slow feed can't block the loop;
set last_checked on failure so broken feeds aren't retried every 60s
- main: validate ids on /start & /delete and numeric env vars at startup;
return 400 (not 500) on bad subscriptions/update input; serve /history
from memory; move get_custom_dirs off the event loop; restrict t=
stripping to YouTube hosts; drop double percent-decode in state guard
- dl_formats/ytdl: enforce requested caption format via
FFmpegSubtitlesConvertor and strip VTT header metadata only in the
pre-cue region so real dialogue is preserved
- ytdl: throttle progress events, dedup adds against pending, clear
filename/size on error and reject out-of-dir trashcan deletes, pin
fork start-method on Linux only
Frontend:
- retry deletes the done record only after a successful re-add
- surface HTTP errors for delete/start and reset the deleting flag
- ignore late 'updated' events for rows no longer in the queue
- track table rows by map key; FileSizePipe uses base-1024
Also: HTTPS-aware Docker healthcheck, dead-code removal, and shared
helpers for path-containment and yt-dlp option merging. Adds/updates
unit tests throughout (250 backend tests passing).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
