Cloud-deploy operators on Discussion #295 needed to leave the
admin UI for docker logs / journalctl to see what the service was
doing. Mirror log.Default() output into an in-memory ring buffer
and expose it under /setup/logs so the admin UI can show a live
trace alongside the existing tabs.
The buffer is a second sink under log.SetOutput(io.MultiWriter(
os.Stderr, buf)) — stderr keeps receiving every line verbatim,
so docker logs / journalctl are unaffected. Default capacity
2000 lines (~400 KB), tunable via SOUNDTOUCH_LOG_BUFFER_LINES.
- pkg/service/logbuf: io.Writer ring with \n splitting,
partial-line buffering, monotonic Seq, Since(since, limit)
reporting dropped count when the caller falls behind.
- New /setup/logs (GET) returns {entries, nextSince, dropped,
capacity}. Polls at 1.5s while the tab is active; paused on
document.hidden.
- "8. Logs" tab with substring filter, tail-follow toggle
(auto-disables when the user scrolls up), monospace dark view.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Tobias GesellchenandClaude Opus 4.7