overleaf/services/notifications/app.ts

// Metrics must be initialized before importing anything else
import '@overleaf/metrics/initialize.js'
import metrics from '@overleaf/metrics'
import Settings from '@overleaf/settings'
import logger from '@overleaf/logger'
import express, {
  type Request,
  type Response,
  type ErrorRequestHandler,
  type NextFunction,
} from 'express'
import { mongoClient } from './app/js/mongodb.js'
import NotificationsController from './app/js/NotificationsController.ts'
import HealthCheckController from './app/js/HealthCheckController.ts'
import {
  InvalidParamsError,
  InvalidRequestError,
} from '@overleaf/validation-tools'

const app = express()

logger.initialize('notifications')

metrics.memory.monitor(logger)
metrics.open_sockets.monitor()

app.use(express.json())
app.use(metrics.http.monitor(logger))

metrics.injectMetricsRoute(app)

app.post('/user/:user_id', NotificationsController.addNotification)
app.get('/user/:user_id', NotificationsController.getUserNotifications)
app.delete(
  '/user/:user_id/notification/:notification_id',
  NotificationsController.removeNotificationId
)
app.delete('/user/:user_id', NotificationsController.removeNotificationKey)
app.delete('/key/:key', NotificationsController.removeNotificationByKeyOnly)
app.get('/key/:key/count', NotificationsController.countNotificationsByKeyOnly)
app.delete(
  '/key/:key/bulk',
  NotificationsController.deleteUnreadNotificationsByKeyOnlyBulk
)

app.get('/status', (req, res) => res.send('notifications is up'))

app.get('/health_check', HealthCheckController.check)

app.get('*', (req, res) => res.sendStatus(404))

const handleApiError: ErrorRequestHandler = (
  err: Error,
  req: Request,
  res: Response,
  next: NextFunction
) => {
  req.logger.addFields({ err })
  if (err instanceof InvalidParamsError) {
    req.logger.setLevel('warn')
    res.sendStatus(404)
  } else if (err instanceof InvalidRequestError) {
    req.logger.setLevel('warn')
    res.sendStatus(400)
  } else {
    req.logger.setLevel('error')
    res.sendStatus(500)
  }
}

app.use(handleApiError)

const host = Settings.internal.notifications?.host || '127.0.0.1'
const port = Settings.internal.notifications?.port || 3042
try {
  await mongoClient.connect()
} catch (err) {
  logger.fatal({ err }, 'Cannot connect to mongo. Exiting.')
  process.exit(1)
}

if (import.meta.url === `file://${process.argv[1]}`) {
  app.listen(port, host, () =>
    logger.debug({}, `notifications starting up, listening on ${host}:${port}`)
  )
}
export default app