fix(obico): POST image bytes directly to ML API instead of callback URL (#1003)

The ML API previously called back into Bambuddy to fetch snapshots,
  which failed behind reverse proxies with external auth (Authelia, etc.).
  Now the detection loop captures the JPEG locally and POSTs it directly
  as multipart form data — no callback URL, no nonce cache, no
  external_url dependency.
This commit is contained in:
maziggy
2026-04-17 09:06:31 +02:00
parent c6aba21278
commit 475e34ebda
20 changed files with 62 additions and 313 deletions
+22 -88
View File
@@ -5,13 +5,7 @@ from unittest.mock import AsyncMock, MagicMock, patch
import pytest
from backend.app.schemas.settings import AppSettingsUpdate
from backend.app.services.obico_detection import (
FRAME_CACHE_TTL,
ObicoDetectionService,
_frame_cache,
pop_frame,
stash_frame,
)
from backend.app.services.obico_detection import ObicoDetectionService
from backend.app.services.obico_smoothing import WARMUP_FRAMES
FAKE_JPEG = b"\xff\xd8\xff\xe0\x00\x10JFIF\x00\x01\x01\x00\x00\x01\x00\x01\x00\x00\xff\xd9"
@@ -139,7 +133,6 @@ class TestPollOneStateLifecycle:
"action": "notify",
"poll_interval": 10,
"enabled_printers": None,
"external_url": "http://bambuddy:8000",
}
status = MagicMock(state="RUNNING", task_name="new_task", subtask_name="")
@@ -147,7 +140,7 @@ class TestPollOneStateLifecycle:
mock_response.json.return_value = {"detections": []}
mock_response.raise_for_status = MagicMock()
mock_client = MagicMock()
mock_client.get = AsyncMock(return_value=mock_response)
mock_client.post = AsyncMock(return_value=mock_response)
mock_client.__aenter__ = AsyncMock(return_value=mock_client)
mock_client.__aexit__ = AsyncMock(return_value=False)
@@ -172,12 +165,11 @@ class TestPollOneStateLifecycle:
"action": "notify",
"poll_interval": 10,
"enabled_printers": None,
"external_url": "http://bambuddy:8000",
}
status = MagicMock(state="RUNNING", task_name="job", subtask_name="")
mock_client = MagicMock()
mock_client.get = AsyncMock(side_effect=RuntimeError("connection refused"))
mock_client.post = AsyncMock(side_effect=RuntimeError("connection refused"))
mock_client.__aenter__ = AsyncMock(return_value=mock_client)
mock_client.__aexit__ = AsyncMock(return_value=False)
@@ -201,7 +193,6 @@ class TestPollOneStateLifecycle:
"action": "notify",
"poll_interval": 10,
"enabled_printers": None,
"external_url": "http://bambuddy:8000",
}
status = MagicMock(state="RUNNING", task_name="job", subtask_name="")
@@ -219,7 +210,7 @@ class TestPollOneStateLifecycle:
mock_response.json.return_value = {"detections": [["failure", 0.9, [0, 0, 1, 1]]]}
mock_response.raise_for_status = MagicMock()
mock_client = MagicMock()
mock_client.get = AsyncMock(return_value=mock_response)
mock_client.post = AsyncMock(return_value=mock_response)
mock_client.__aenter__ = AsyncMock(return_value=mock_client)
mock_client.__aexit__ = AsyncMock(return_value=False)
@@ -235,70 +226,11 @@ class TestPollOneStateLifecycle:
assert mock_action.call_count == 1
class TestFrameCache:
"""One-shot JPEG cache that lets us sidestep Obico's 5s read timeout.
Obico's ML API fetches snapshots via `GET /p/?img=URL` with `timeout=(0.1, 5)`.
Our /camera/snapshot can exceed that on cold calls (RTSP keyframe wait). So the
detection loop captures locally, stashes the JPEG bytes under a nonce, then hands
Obico a URL that returns those bytes instantly. The cache is single-use + TTLed
so a leaked nonce can't be replayed.
"""
def setup_method(self):
_frame_cache.clear()
class TestCheckPrinterPostsImageDirectly:
"""The detection loop must POST JPEG bytes directly to the ML API."""
@pytest.mark.asyncio
async def test_stash_and_pop_roundtrip(self):
nonce = await stash_frame(FAKE_JPEG)
assert nonce # non-empty URL-safe token
data = await pop_frame(nonce)
assert data == FAKE_JPEG
@pytest.mark.asyncio
async def test_nonce_is_single_use(self):
nonce = await stash_frame(FAKE_JPEG)
assert await pop_frame(nonce) == FAKE_JPEG
# Second pop returns None — caches replay protection
assert await pop_frame(nonce) is None
@pytest.mark.asyncio
async def test_unknown_nonce_returns_none(self):
assert await pop_frame("not-a-real-nonce") is None
@pytest.mark.asyncio
async def test_stash_produces_unique_nonces(self):
nonces = {await stash_frame(FAKE_JPEG) for _ in range(10)}
assert len(nonces) == 10
@pytest.mark.asyncio
async def test_expired_entries_are_pruned_on_stash(self):
"""New entries trigger pruning of TTL-expired ones — prevents unbounded growth."""
# Manually seed an entry with a stale timestamp
import time as time_module
_frame_cache["stale-nonce"] = (FAKE_JPEG, time_module.monotonic() - FRAME_CACHE_TTL - 1)
await stash_frame(FAKE_JPEG)
# Stale entry was pruned
assert "stale-nonce" not in _frame_cache
@pytest.mark.asyncio
async def test_pop_rejects_expired_nonce(self):
"""Even if the entry is still in the dict, an expired TTL returns None."""
import time as time_module
_frame_cache["aging-nonce"] = (FAKE_JPEG, time_module.monotonic() - FRAME_CACHE_TTL - 1)
assert await pop_frame("aging-nonce") is None
class TestCheckPrinterUsesCachedFrameUrl:
"""The URL sent to Obico must point at our nonce endpoint, not /camera/snapshot."""
def setup_method(self):
_frame_cache.clear()
@pytest.mark.asyncio
async def test_ml_api_called_with_cached_frame_url(self):
async def test_ml_api_called_with_post_and_image_bytes(self):
svc = ObicoDetectionService()
settings = {
"enabled": True,
@@ -307,7 +239,6 @@ class TestCheckPrinterUsesCachedFrameUrl:
"action": "notify",
"poll_interval": 10,
"enabled_printers": None,
"external_url": "http://bambuddy:8000",
}
status = MagicMock(state="RUNNING", task_name="job", subtask_name="")
@@ -315,7 +246,7 @@ class TestCheckPrinterUsesCachedFrameUrl:
mock_response.json.return_value = {"detections": []}
mock_response.raise_for_status = MagicMock()
mock_client = MagicMock()
mock_client.get = AsyncMock(return_value=mock_response)
mock_client.post = AsyncMock(return_value=mock_response)
mock_client.__aenter__ = AsyncMock(return_value=mock_client)
mock_client.__aexit__ = AsyncMock(return_value=False)
@@ -325,14 +256,18 @@ class TestCheckPrinterUsesCachedFrameUrl:
):
await svc._check_printer(1, status, settings)
# Extract the img URL handed to the ML API
_args, kwargs = mock_client.get.call_args
img_url = kwargs["params"]["img"]
assert img_url.startswith("http://bambuddy:8000/api/v1/obico/cached-frame/")
# The path segment after /cached-frame/ is the nonce itself — that nonce must
# resolve back to our stashed frame (single-use guarantees freshness).
nonce = img_url.rsplit("/", 1)[-1]
assert await pop_frame(nonce) == FAKE_JPEG
# ML API was called via POST
mock_client.post.assert_called_once()
_args, kwargs = mock_client.post.call_args
# URL is the ML API /p/ endpoint
assert _args[0] == "http://obico:3333/p/"
# Image bytes sent as multipart file upload
files = kwargs["files"]
assert "img" in files
filename, data, content_type = files["img"]
assert filename == "snapshot.jpg"
assert data == FAKE_JPEG
assert content_type == "image/jpeg"
@pytest.mark.asyncio
async def test_capture_failure_skips_ml_call(self):
@@ -345,12 +280,11 @@ class TestCheckPrinterUsesCachedFrameUrl:
"action": "notify",
"poll_interval": 10,
"enabled_printers": None,
"external_url": "http://bambuddy:8000",
}
status = MagicMock(state="RUNNING", task_name="job", subtask_name="")
mock_client = MagicMock()
mock_client.get = AsyncMock()
mock_client.post = AsyncMock()
mock_client.__aenter__ = AsyncMock(return_value=mock_client)
mock_client.__aexit__ = AsyncMock(return_value=False)
@@ -360,6 +294,6 @@ class TestCheckPrinterUsesCachedFrameUrl:
):
await svc._check_printer(1, status, settings)
mock_client.get.assert_not_called()
mock_client.post.assert_not_called()
assert svc._last_error is not None
assert "Failed to capture snapshot" in svc._last_error