feat: settings service (get/set/load helpers, load_settings_sync)

fablednetmon/core/settings.py

@@ -0,0 +1,161 @@
+# fablednetmon/core/settings.py
+"""DB-backed application settings.
+
+Keys use dotted notation (e.g. "smtp.host").
+Values are JSON-encoded in the DB.
+
+Usage in create_app() (before event loop):
+    from fablednetmon.core.settings import load_settings_sync
+    settings = load_settings_sync(db_url)
+
+Usage at runtime (inside async handlers):
+    from fablednetmon.core.settings import get_setting, set_setting
+    async with app.db_sessionmaker() as session:
+        value = await get_setting(session, "smtp.host")
+        await set_setting(session, "smtp.host", "mail.example.com")
+"""
+from __future__ import annotations
+import asyncio
+import json
+import logging
+from datetime import datetime, timezone
+from typing import Any
+
+from sqlalchemy import select
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from fablednetmon.models.settings import AppSetting
+
+logger = logging.getLogger(__name__)
+
+_DEFAULT_WEBHOOK_TEMPLATE = (
+    '{"content": "**{{ alert.state }}** — {{ alert.resource }} — '
+    '{{ alert.rule_name }} ({{ alert.metric }} = {{ alert.value }})"}'
+)
+
+# All recognised settings and their defaults.
+# Plugin settings are stored as "plugin.<name>" and handled separately.
+DEFAULTS: dict[str, Any] = {
+    "session.lifetime_hours": 8,
+    "data.retention_days": 90,
+    "monitors.poll_interval_seconds": 60,
+    "smtp.host": "",
+    "smtp.port": 587,
+    "smtp.tls": True,
+    "smtp.username": "",
+    "smtp.password": "",
+    "smtp.recipients": [],
+    "webhook.url": "",
+    "webhook.template": _DEFAULT_WEBHOOK_TEMPLATE,
+    "ansible.sources": [],
+}
+
+
+# ─────────────────────────────────────────────────────────────────────────────
+# Async helpers (use inside request handlers / scheduled tasks)
+# ─────────────────────────────────────────────────────────────────────────────
+
+async def get_setting(session: AsyncSession, key: str) -> Any:
+    """Return the value for key, or the default if not set."""
+    result = await session.execute(
+        select(AppSetting).where(AppSetting.key == key)
+    )
+    row = result.scalar_one_or_none()
+    if row is None:
+        return DEFAULTS.get(key)
+    return json.loads(row.value_json)
+
+
+async def set_setting(session: AsyncSession, key: str, value: Any) -> None:
+    """Upsert a setting. Call inside an active transaction."""
+    result = await session.execute(
+        select(AppSetting).where(AppSetting.key == key)
+    )
+    row = result.scalar_one_or_none()
+    now = datetime.now(timezone.utc)
+    if row is None:
+        session.add(AppSetting(key=key, value_json=json.dumps(value), updated_at=now))
+    else:
+        row.value_json = json.dumps(value)
+        row.updated_at = now
+
+
+async def get_all_settings(session: AsyncSession) -> dict[str, Any]:
+    """Return flat key→value dict with defaults filled in for missing keys."""
+    result = await session.execute(select(AppSetting))
+    stored = {row.key: json.loads(row.value_json) for row in result.scalars()}
+    out: dict[str, Any] = {}
+    for key, default in DEFAULTS.items():
+        out[key] = stored.get(key, default)
+    # Include any plugin.* keys stored in DB
+    for key, value in stored.items():
+        if key.startswith("plugin.") and key not in out:
+            out[key] = value
+    return out
+
+
+# ─────────────────────────────────────────────────────────────────────────────
+# Structured config extractors (dict shapes expected by existing consumers)
+# ─────────────────────────────────────────────────────────────────────────────
+
+def to_smtp_cfg(settings: dict[str, Any]) -> dict:
+    return {
+        "host": settings.get("smtp.host", ""),
+        "port": settings.get("smtp.port", 587),
+        "tls": settings.get("smtp.tls", True),
+        "username": settings.get("smtp.username", ""),
+        "password": settings.get("smtp.password", ""),
+        "recipients": settings.get("smtp.recipients", []),
+    }
+
+
+def to_webhook_cfg(settings: dict[str, Any]) -> dict:
+    return {
+        "url": settings.get("webhook.url", ""),
+        "template": settings.get("webhook.template", _DEFAULT_WEBHOOK_TEMPLATE),
+    }
+
+
+def to_ansible_cfg(settings: dict[str, Any]) -> dict:
+    return {"sources": settings.get("ansible.sources", [])}
+
+
+def to_plugins_cfg(settings: dict[str, Any]) -> dict:
+    """Assemble {plugin_name: {...config}} from all plugin.* keys."""
+    result = {}
+    for key, value in settings.items():
+        if key.startswith("plugin."):
+            name = key[len("plugin."):]
+            result[name] = value
+    return result
+
+
+# ─────────────────────────────────────────────────────────────────────────────
+# Synchronous loader — safe to call before the event loop starts
+# ─────────────────────────────────────────────────────────────────────────────
+
+def load_settings_sync(db_url: str) -> dict[str, Any]:
+    """Load all settings from DB synchronously via asyncio.run().
+
+    Safe to call in create_app() before the Quart event loop starts.
+    Returns flat key→value dict with defaults filled in.
+    """
+    async def _load() -> dict[str, Any]:
+        from sqlalchemy.ext.asyncio import create_async_engine, async_sessionmaker
+        engine = create_async_engine(db_url, echo=False)
+        factory = async_sessionmaker(engine, expire_on_commit=False)
+        try:
+            async with factory() as session:
+                result = await session.execute(select(AppSetting))
+                return {row.key: json.loads(row.value_json) for row in result.scalars()}
+        finally:
+            await engine.dispose()
+
+    stored = asyncio.run(_load())
+    out: dict[str, Any] = {}
+    for key, default in DEFAULTS.items():
+        out[key] = stored.get(key, default)
+    for key, value in stored.items():
+        if key.startswith("plugin.") and key not in out:
+            out[key] = value
+    return out