ML-007: add retraining pipeline and API

Closes #13

.gitignore

@@ -4,6 +4,7 @@
 /.vscode
 __pycache__/
 *.pyc
+*.egg-info/
 .mypy_cache/
 .pytest_cache/
 .ruff_cache/

CHANGELOG.md

@@ -8,3 +8,4 @@
 - Persistente, validierte und gegen Path Traversal gehärtete Model Registry
 - Reproduzierbares Packaging, CI-Gates und gehärteter non-root Container
 - Definierte API-Fehler und korrigierte Evaluationsmetriken
+- Scheduler-tauglicher Retraining-Service mit API und atomischem Registry-Update

README.md

@@ -43,6 +43,7 @@ uvicorn app.main:app --reload
 - `http://127.0.0.1:8000/docs/` - OpenAPI-Dokumentation
 - `http://127.0.0.1:8000/v1/entities` - Home-Assistant-Entities
 - `http://127.0.0.1:8000/ml/health` - Registry-/Serving-Health
+- `POST http://127.0.0.1:8000/ml/retrain` - Modell-Metadaten aktualisieren
 
 Ohne vollständige HA-Konfiguration liefert `/v1/entities` bewusst `503`.
 

app/ml/__init__.py

@@ -1,5 +1,14 @@
 
 """Machine-Learning-Grundbausteine für SillyHome Next."""
-__all__ = ["FeatureStore", "FeatureVector", "TrainedArtifact", "TrainingPipeline"]
+__all__ = [
+    "FeatureStore",
+    "FeatureVector",
+    "RetrainingResult",
+    "RetrainingService",
+    "TrainedArtifact",
+    "TrainingPipeline",
+    "retrain_model",
+]
 from app.ml.feature_store import FeatureStore, FeatureVector
+from app.ml.retraining import RetrainingResult, RetrainingService, retrain_model
 from app.ml.training import TrainedArtifact, TrainingPipeline

app/ml/registry/model_registry.py

@@ -5,6 +5,7 @@ import logging
 import os
 from pathlib import Path
 import re
+from threading import RLock
 from collections.abc import Iterable
 
 from app.ml.training import TrainedArtifact
@@ -19,22 +20,31 @@ class ModelRegistry:
         self._root = Path(root).resolve()
         self._root.mkdir(parents=True, exist_ok=True)
         self._artifacts: dict[str, TrainedArtifact] = {}
+        self._lock = RLock()
         self._load_existing()
 
     def register(self, artifact: TrainedArtifact) -> TrainedArtifact:
+        registered, _ = self.register_with_status(artifact)
+        return registered
+
+    def register_with_status(self, artifact: TrainedArtifact) -> tuple[TrainedArtifact, bool]:
         self._validate_artifact_id(artifact.artifact_id)
+        with self._lock:
+            replaced = artifact.artifact_id in self._artifacts
             self._persist(artifact)
             self._artifacts[artifact.artifact_id] = artifact
-        return artifact
+        return artifact, replaced
 
     def load_artifact(self, artifact_id: str) -> TrainedArtifact:
         self._validate_artifact_id(artifact_id)
+        with self._lock:
             if artifact_id not in self._artifacts:
                 raise KeyError(f"Artifact '{artifact_id}' nicht registriert.")
             return self._artifacts[artifact_id]
 
     def list_models(self) -> Iterable[TrainedArtifact]:
-        return list(self._artifacts.values())
+        with self._lock:
+            return [self._artifacts[key] for key in sorted(self._artifacts)]
 
     def _load_existing(self) -> None:
         for source in sorted(self._root.glob("*.json")):

app/ml/retraining.py

@@ -0,0 +1,43 @@
+from __future__ import annotations
+
+from collections.abc import Iterable
+from dataclasses import dataclass
+
+from app.ml.feature_store import FeatureStore, FeatureVector
+from app.ml.registry.model_registry import ModelRegistry
+from app.ml.training import TrainedArtifact, TrainingPipeline
+
+
+@dataclass(frozen=True)
+class RetrainingResult:
+    artifact: TrainedArtifact
+    replaced: bool
+
+
+class RetrainingService:
+    """Runs one retraining cycle without owning scheduling or background threads."""
+
+    def __init__(self, registry: ModelRegistry) -> None:
+        self._registry = registry
+
+    def retrain(
+        self,
+        artifact_id: str,
+        vectors: Iterable[FeatureVector],
+    ) -> RetrainingResult:
+        store = FeatureStore()
+        store.add_batch(vectors)
+        pipeline = TrainingPipeline(store)
+        artifact = pipeline.run(artifact_id)
+        _, replaced = self._registry.register_with_status(artifact)
+        return RetrainingResult(artifact=artifact, replaced=replaced)
+
+
+def retrain_model(
+    registry: ModelRegistry,
+    artifact_id: str,
+    vectors: Iterable[FeatureVector],
+) -> RetrainingResult:
+    """Scheduler-compatible entry point for exactly one retraining run."""
+
+    return RetrainingService(registry).retrain(artifact_id, vectors)

backend/routes/ml.py

@@ -10,6 +10,7 @@ from pydantic import BaseModel, Field
 from app.ml.feature_store import FeatureVector
 from app.ml.predictor import Predictor
 from app.ml.registry.model_registry import ModelRegistry
+from app.ml.retraining import retrain_model
 
 logger = logging.getLogger(__name__)
 
@@ -45,6 +46,23 @@ class ModelsResponse(BaseModel):
     models: list[str]
 
 
+class TrainingSample(BaseModel):
+    sensor_id: str = Field(min_length=1)
+    values: dict[str, float]
+    label: str | None = None
+
+
+class RetrainRequest(BaseModel):
+    model_id: str = Field(..., alias="modelId", min_length=1, max_length=128)
+    samples: list[TrainingSample] = Field(min_length=1)
+
+
+class RetrainResponse(BaseModel):
+    model_id: str
+    supported_sensors: list[str]
+    replaced: bool
+
+
 @router.get("/health", response_model=HealthResponse, status_code=200)
 def health() -> HealthResponse:
     return HealthResponse(status="ok")
@@ -57,6 +75,31 @@ def list_models(request: Request) -> ModelsResponse:
     return ModelsResponse(models=models)
 
 
+@router.post("/retrain", response_model=RetrainResponse, status_code=200)
+def retrain(payload: RetrainRequest, request: Request) -> RetrainResponse:
+    registry = _require_registry(request)
+    vectors = [
+        FeatureVector(
+            sensor_id=sample.sensor_id,
+            values=sample.values,
+            label=sample.label,
+        )
+        for sample in payload.samples
+    ]
+    try:
+        result = retrain_model(registry, payload.model_id, vectors)
+    except ValueError as exc:
+        raise HTTPException(
+            status_code=status.HTTP_422_UNPROCESSABLE_CONTENT,
+            detail=str(exc),
+        ) from exc
+    return RetrainResponse(
+        model_id=result.artifact.artifact_id,
+        supported_sensors=list(result.artifact.supported_sensors),
+        replaced=result.replaced,
+    )
+
+
 @router.post("/predict", response_model=PredictResponse, status_code=200)
 def predict(payload: PredictRequest, request: Request) -> PredictResponse:
     registry = _require_registry(request)

docs/ml_api.md

@@ -12,6 +12,7 @@ Modell-Artefakt- und Vorhersage-Schnittstelle.
 - Standard: `http://127.0.0.1:8000/ml`
 - Health: `/health`
 - Modelle: `/models`
+- Retraining: `/retrain`
 - Einzelvorhersage: `/predict`
 - Batchvorhersage: `/batch`
 
@@ -65,6 +66,35 @@ Einzelne Vorhersage für einen Sensor.
 }
 ```
 
+### `POST /ml/retrain`
+
+Trainiert die Artefakt-Metadaten aus neuen Sensordaten. Existiert `modelId`
+bereits, wird das Artefakt atomisch ersetzt und beim nächsten Prozessstart aus
+dem Modellverzeichnis geladen.
+
+**Request**
+```json
+{
+  "modelId": "home-model",
+  "samples": [
+    {
+      "sensor_id": "sensor.kitchen",
+      "values": {"temperature": 21.0},
+      "label": "occupied"
+    }
+  ]
+}
+```
+
+**Antwort**
+```json
+{
+  "model_id": "home-model",
+  "supported_sensors": ["sensor.kitchen"],
+  "replaced": false
+}
+```
+
 ### `POST /ml/batch`
 
 Batch-Vorhersage für mehrere Sensorwerte.
@@ -114,11 +144,15 @@ Batch-Vorhersage für mehrere Sensorwerte.
 ## Betrieb
 
 Die produktive App lädt Artefakte aus `SILLYHOME_MODEL_STORE`. Neue Artefakte
-werden derzeit intern über `ModelRegistry.register(...)` registriert. Die
+werden über `/ml/retrain`, `RetrainingService` oder direkt über
-Registry speichert validiertes JSON atomisch und lädt es beim Neustart.
+`ModelRegistry.register(...)` registriert. Die Registry speichert validiertes
+JSON atomisch und lädt es beim Neustart. Die API sollte nur in einem
+vertrauenswürdigen Netz oder hinter einem authentifizierenden Reverse Proxy
+erreichbar sein.
 
 ## Verweise
 
 - `app/ml/predictor.py`
+- `app/ml/retraining.py`
 - `app/ml/registry/model_registry.py`
 - `backend/routes/ml.py`

docs/ml_training.md

@@ -38,6 +38,21 @@ Der Report enthält:
 
 Das trainierte Artefakt kann anschließend über `ModelRegistry.register(artifact)` bereitgestellt werden. Die ML-Serving-API stellt es unter `/ml/predict` und `/ml/batch` zur Verfügung.
 
+## 5. Retraining ausführen
+
+`RetrainingService.retrain(...)` führt genau einen Trainingslauf aus und ersetzt
+ein vorhandenes Artefakt mit derselben ID atomisch in der Registry:
+
+```python
+service = RetrainingService(registry)
+result = service.retrain("home-model", vectors)
+```
+
+Scheduler, Cronjobs oder Home-Assistant-Automationen können alternativ die
+zustandslose Funktion `retrain_model(registry, artifact_id, vectors)` aufrufen.
+Der Service startet bewusst keinen eigenen Hintergrundprozess. Über
+`POST /ml/retrain` kann derselbe Ablauf per API angestoßen werden.
+
 ## Hinweise
 - Für reproduzierbare Sensor-Reihenfolgen wird in `TrainingPipeline.run(...)` eine sortierte Sensor-Liste verwendet.
 - Fehlende Trainingsdaten lösen `ValueError` aus; nicht registrierte Artefakte lösen `KeyError` aus.

tests/api/test_ml_routes.py

@@ -50,3 +50,60 @@ def test_unsupported_sensor_returns_422(tmp_path: Path) -> None:
         )
 
     assert response.status_code == 422
+
+
+def test_retrain_creates_and_replaces_persisted_model(tmp_path: Path) -> None:
+    from app.ml.registry.model_registry import ModelRegistry
+
+    registry = ModelRegistry(tmp_path)
+    with TestClient(app) as client:
+        app.state.registry = registry
+        created = client.post(
+            "/ml/retrain",
+            json={
+                "modelId": "home-model",
+                "samples": [
+                    {
+                        "sensor_id": "sensor.kitchen",
+                        "values": {"temperature": 21.0},
+                    }
+                ],
+            },
+        )
+        replaced = client.post(
+            "/ml/retrain",
+            json={
+                "modelId": "home-model",
+                "samples": [
+                    {
+                        "sensor_id": "sensor.bedroom",
+                        "values": {"temperature": 18.0},
+                    }
+                ],
+            },
+        )
+
+    assert created.status_code == 200
+    assert created.json() == {
+        "model_id": "home-model",
+        "supported_sensors": ["sensor.kitchen"],
+        "replaced": False,
+    }
+    assert replaced.status_code == 200
+    assert replaced.json() == {
+        "model_id": "home-model",
+        "supported_sensors": ["sensor.bedroom"],
+        "replaced": True,
+    }
+    restarted = ModelRegistry(tmp_path)
+    assert restarted.load_artifact("home-model").supported_sensors == ("sensor.bedroom",)
+
+
+def test_retrain_rejects_empty_samples() -> None:
+    with TestClient(app) as client:
+        response = client.post(
+            "/ml/retrain",
+            json={"modelId": "home-model", "samples": []},
+        )
+
+    assert response.status_code == 422

tests/ml/test_model_registry.py

@@ -19,6 +19,17 @@ def test_registry_loads_persisted_artifacts_after_restart(tmp_path: Path) -> Non
     assert restarted.load_artifact("model-v1") == artifact
 
 
+def test_registry_replaces_persisted_artifact_after_restart(tmp_path: Path) -> None:
+    registry = ModelRegistry(tmp_path)
+    registry.register(TrainedArtifact("model-v1", ("sensor.kitchen",)))
+    replacement = TrainedArtifact("model-v1", ("sensor.bedroom",))
+
+    registry.register(replacement)
+
+    assert registry.load_artifact("model-v1") == replacement
+    assert ModelRegistry(tmp_path).load_artifact("model-v1") == replacement
+
+
 @pytest.mark.parametrize("artifact_id", ["../escape", "nested/model", "..", ""])
 def test_registry_rejects_unsafe_artifact_ids(tmp_path: Path, artifact_id: str) -> None:
     registry = ModelRegistry(tmp_path)

tests/ml/test_retraining.py

@@ -0,0 +1,39 @@
+from __future__ import annotations
+
+from pathlib import Path
+
+import pytest
+
+from app.ml.feature_store import FeatureVector
+from app.ml.registry.model_registry import ModelRegistry
+from app.ml.retraining import RetrainingService, retrain_model
+
+
+def _vector(sensor_id: str) -> FeatureVector:
+    return FeatureVector(sensor_id=sensor_id, values={"temperature": 21.0})
+
+
+def test_retraining_registers_new_artifact(tmp_path: Path) -> None:
+    registry = ModelRegistry(tmp_path)
+
+    result = retrain_model(registry, "home-model", [_vector("sensor.kitchen")])
+
+    assert result.replaced is False
+    assert registry.load_artifact("home-model") == result.artifact
+
+
+def test_retraining_replaces_existing_artifact(tmp_path: Path) -> None:
+    registry = ModelRegistry(tmp_path)
+    service = RetrainingService(registry)
+    service.retrain("home-model", [_vector("sensor.kitchen")])
+
+    result = service.retrain("home-model", [_vector("sensor.bedroom")])
+
+    assert result.replaced is True
+    assert result.artifact.supported_sensors == ("sensor.bedroom",)
+    assert ModelRegistry(tmp_path).load_artifact("home-model") == result.artifact
+
+
+def test_retraining_rejects_empty_training_data(tmp_path: Path) -> None:
+    with pytest.raises(ValueError, match="keine Trainingsdaten"):
+        retrain_model(ModelRegistry(tmp_path), "home-model", [])