matrix-alertbot/matrix_alertbot/webhook.py

from __future__ import annotations

import logging
from typing import Any

from aiohttp import web, web_request
from aiohttp_prometheus_exporter.handler import metrics
from aiohttp_prometheus_exporter.middleware import prometheus_middleware_factory
from diskcache import Cache
from nio import AsyncClient, SendRetryError

from matrix_alertbot.chat_functions import send_text_to_room
from matrix_alertbot.config import Config
from matrix_alertbot.storage import Alert

logger = logging.getLogger(__name__)

routes = web.RouteTableDef()


@routes.post("/alert")
async def create_alert(request: web_request.Request) -> web.Response:
    data = await request.json()
    logger.info(f"Received alert: {data}")
    client: AsyncClient = request.app["client"]
    config: Config = request.app["config"]
    cache: Cache = request.app["cache"]

    plaintext = ""
    html = ""
    for i, alert in enumerate(data["alerts"]):
        alert = Alert.from_dict(alert)

        if i != 0:
            plaintext += "\n"
            html += "<br/>\n"
        plaintext += alert.plaintext()
        html += alert.html()

    try:
        event = await send_text_to_room(
            client, config.room_id, plaintext, html, notice=False
        )
    except SendRetryError as e:
        logger.error(e)
        return web.Response(status=500)

    fingerprints = tuple(alert["fingerprint"] for alert in data["alerts"])
    cache.set(
        event.event_id, fingerprints, expire=config.cache_expire_time, tag="event"
    )
    return web.Response(status=200)


class Webhook:
    def __init__(self, client: AsyncClient, cache: Cache, config: Config) -> None:
        self.app = web.Application(logger=logger)
        self.app["client"] = client
        self.app["config"] = config
        self.app["cache"] = cache
        self.app.add_routes(routes)

        self.app.middlewares.append(prometheus_middleware_factory())
        self.app.router.add_get("/metrics", metrics())

        self.runner = web.AppRunner(self.app)

        self.config = config
        self.address = config.address
        self.port = config.port
        self.socket = config.socket

    async def start(self) -> None:
        await self.runner.setup()

        site: web.BaseSite
        if self.address and self.port:
            site = web.TCPSite(self.runner, self.address, self.port)
            logger.info(f"Listenning on {self.address}:{self.port}")
        elif self.socket:
            site = web.UnixSite(self.runner, self.socket)
            logger.info(f"Listenning on unix://{self.socket}")

        await site.start()

    async def close(self) -> None:
        await self.runner.cleanup()