Files
FabledSteward/fablednetmon/core/alerts.py
T

241 lines
7.7 KiB
Python

from __future__ import annotations
import asyncio
import logging
import uuid
from datetime import datetime, timezone
from typing import TYPE_CHECKING
from sqlalchemy import select
from sqlalchemy.ext.asyncio import AsyncSession
from fablednetmon.models.alerts import (
AlertEvent,
AlertOperator,
AlertRule,
AlertState,
AlertStateEnum,
)
from fablednetmon.models.metrics import PluginMetric
if TYPE_CHECKING:
from quart import Quart
logger = logging.getLogger(__name__)
_app: "Quart | None" = None
def init_alerts(app: "Quart") -> None:
"""Store app reference for use in notification dispatch tasks."""
global _app
_app = app
async def record_metric(
session: AsyncSession,
source_module: str,
resource_name: str,
metric_name: str,
value: float,
) -> None:
"""Write a metric row and evaluate alert rules inline.
Must be called inside an active transaction:
async with session.begin():
await record_metric(session, ...)
Notification I/O is deferred via asyncio.create_task() so no network
calls occur while the transaction is open.
"""
now = datetime.now(timezone.utc)
# Write metric row
metric = PluginMetric(
source_module=source_module,
resource_name=resource_name,
metric_name=metric_name,
value=value,
recorded_at=now,
)
session.add(metric)
await session.flush()
# Load matching enabled rules
result = await session.execute(
select(AlertRule).where(
AlertRule.source_module == source_module,
AlertRule.resource_name == resource_name,
AlertRule.metric_name == metric_name,
AlertRule.enabled.is_(True),
)
)
rules = result.scalars().all()
for rule in rules:
state_result = await session.execute(
select(AlertState).where(AlertState.rule_id == rule.id)
)
alert_state = state_result.scalar_one_or_none()
if alert_state is None:
logger.warning(f"No alert_state row for rule {rule.id}, skipping")
continue
notifications = await _evaluate_rule(session, rule, alert_state, value, now)
for notif_type, event_id in notifications:
if _app is not None:
asyncio.create_task(
_dispatch_notification(
_app, notif_type, rule, value, event_id
)
)
def _is_breached(value: float, operator: AlertOperator, threshold: float) -> bool:
op = operator.value
if op == ">":
return value > threshold
if op == "<":
return value < threshold
if op == ">=":
return value >= threshold
if op == "<=":
return value <= threshold
if op == "==":
return value == threshold
if op == "!=":
return value != threshold
return False
async def _evaluate_rule(
session: AsyncSession,
rule: AlertRule,
state: AlertState,
value: float,
now: datetime,
) -> list[tuple[str, str]]:
"""Evaluate a single rule against a metric value. Returns list of (notif_type, event_id)."""
breached = _is_breached(value, rule.operator, rule.threshold)
from_state = state.state
notifications: list[tuple[str, str]] = []
if state.state == AlertStateEnum.inactive:
if breached:
state.consecutive_failure_count = 1
if state.consecutive_failure_count >= rule.consecutive_failures_required:
state.state = AlertStateEnum.firing
state.last_transition_at = now
event_id = _add_event(session, rule.id, from_state.value, "firing", value, now)
notifications.append(("firing", event_id))
else:
state.state = AlertStateEnum.pending
state.last_transition_at = now
elif state.state == AlertStateEnum.pending:
if breached:
state.consecutive_failure_count += 1
if state.consecutive_failure_count >= rule.consecutive_failures_required:
state.state = AlertStateEnum.firing
state.last_transition_at = now
event_id = _add_event(session, rule.id, from_state.value, "firing", value, now)
notifications.append(("firing", event_id))
else:
state.consecutive_failure_count = 0
state.state = AlertStateEnum.inactive
state.last_transition_at = now
elif state.state == AlertStateEnum.firing:
if not breached:
# RESOLVED is transient: record event, notify, then immediately go inactive
event_id = _add_event(session, rule.id, from_state.value, "resolved", value, now)
notifications.append(("resolved", event_id))
state.consecutive_failure_count = 0
state.state = AlertStateEnum.inactive
state.last_transition_at = now
elif state.state == AlertStateEnum.acknowledged:
if not breached:
event_id = _add_event(session, rule.id, from_state.value, "resolved", value, now)
notifications.append(("resolved", event_id))
state.consecutive_failure_count = 0
state.state = AlertStateEnum.inactive
state.last_transition_at = now
state.acknowledged_by = None
state.acknowledged_at = None
else:
state.consecutive_failure_count += 1
if state.consecutive_failure_count >= rule.consecutive_failures_required:
state.state = AlertStateEnum.firing
state.last_transition_at = now
event_id = _add_event(session, rule.id, from_state.value, "firing", value, now)
notifications.append(("firing", event_id))
await session.flush()
return notifications
def _add_event(
session: AsyncSession,
rule_id: str,
from_state: str,
to_state: str,
value: float,
now: datetime,
) -> str:
"""Add an AlertEvent row and return its ID."""
event_id = str(uuid.uuid4())
event = AlertEvent(
id=event_id,
rule_id=rule_id,
from_state=from_state,
to_state=to_state,
metric_value=value,
transitioned_at=now,
)
session.add(event)
return event_id
async def _dispatch_notification(
app: "Quart",
notif_type: str,
rule: AlertRule,
value: float,
event_id: str,
) -> None:
"""Run after the transaction commits. Sends notifications and updates the event row."""
from fablednetmon.core.notifications import dispatch_notifications
alert_data = {
"rule_name": rule.name,
"state": notif_type.upper(),
"metric": rule.metric_name,
"value": value,
"threshold": rule.threshold,
"resource": rule.resource_name,
"source_module": rule.source_module,
"timestamp": datetime.now(timezone.utc).isoformat(),
}
smtp_cfg = app.config.get("SMTP", {})
webhook_cfg = app.config.get("WEBHOOK", {})
results = await dispatch_notifications(smtp_cfg, webhook_cfg, alert_data)
# Update event row with delivery results in a new transaction
async with app.db_sessionmaker() as db:
async with db.begin():
event_result = await db.execute(
select(AlertEvent).where(AlertEvent.id == event_id)
)
event = event_result.scalar_one_or_none()
if event:
email_r = results.get("email")
if email_r:
event.email_sent = email_r["sent"]
event.email_error = email_r.get("error")
webhook_r = results.get("webhook")
if webhook_r:
event.webhook_sent = webhook_r["sent"]
event.webhook_error = webhook_r.get("error")