Files
bambuddy/backend
maziggy 0406487eb3 Fix: Add Printer no longer hangs the container on P1S (#1445)
The pre-insert MQTT probe added in 0.2.4.2 (b51598ea) had two bugs that
  compounded on P1S firmware specifically:

  1. Fixed 2-second sleep was too short. P1S broker + TLS handshake
  routinely needs 3-5s to surface CONNACK on a cold MQTT session (same
  firmware family with the documented "broker stops publishing but TCP
  stays alive" quirk at bambu_mqtt.py:3181), so the probe falsely rejected
  a printer that would have connected fine. H2C's broker is snappier and
  cleared the 2s window without trouble — which is why the reporter's
  H2C added without issue and only the P1S misbehaved.

  2. client.disconnect() ran synchronously on the asyncio thread.
  BambuMQTTClient.disconnect() ends in paho's loop_stop() which joins
  the network thread; if that thread was still mid-TLS-handshake to the
  slow P1S socket when teardown ran, the join blocked the asyncio thread
  for as long as the handshake took to complete or fail. POST /printers
  wedged, every other HTTP request queued behind it, Docker healthcheck
  timed out — user-visible symptom: "the container hangs."

  Fix:
  - Replace the fixed sleep with a polling loop (8s budget, 200ms tick,
    early-returns the moment state.connected flips True). Slow brokers
    get the headroom they need; happy-path connects still finish in
    ~1-2s. Constants exposed as PROBE_TIMEOUT_SECONDS / PROBE_POLL_
    INTERVAL_SECONDS class attributes so tests can dial them down.
  - Move client.disconnect() to await asyncio.to_thread(...) so paho's
    thread-join can never block the event loop.

  The empty-card-report-prevention goal of the original probe stays
  intact: a genuinely wrong access code still results in connected=False
  after the 8s budget, the 400 with code=printer_connection_failed
  still fires, the row is still never persisted.
2026-05-20 09:39:10 +02:00
..