server/lib/opentelemetry/metrics.ts

   1 import { Application, Request, Response } from 'express'
   2 import { Meter, metrics } from '@opentelemetry/api'
   3 import { PrometheusExporter } from '@opentelemetry/exporter-prometheus'
   4 import { MeterProvider } from '@opentelemetry/sdk-metrics'
   5 import { logger } from '@server/helpers/logger'
   6 import { CONFIG } from '@server/initializers/config'
   7 import { MVideoImmutable } from '@server/types/models'
   8 import { PlaybackMetricCreate } from '@shared/models'
   9 import {
  10   BittorrentTrackerObserversBuilder,
  11   JobQueueObserversBuilder,
  12   LivesObserversBuilder,
  13   NodeJSObserversBuilder,
  14   PlaybackMetrics,
  15   StatsObserversBuilder,
  16   ViewersObserversBuilder
  17 } from './metric-helpers'
  18
  19 class OpenTelemetryMetrics {
  20
  21   private static instance: OpenTelemetryMetrics
  22
  23   private meter: Meter
  24
  25   private onRequestDuration: (req: Request, res: Response) => void
  26
  27   private playbackMetrics: PlaybackMetrics
  28
  29   private constructor () {}
  30
  31   init (app: Application) {
  32     if (CONFIG.OPEN_TELEMETRY.METRICS.ENABLED !== true) return
  33
  34     app.use((req, res, next) => {
  35       res.once('finish', () => {
  36         if (!this.onRequestDuration) return
  37
  38         this.onRequestDuration(req as Request, res as Response)
  39       })
  40
  41       next()
  42     })
  43   }
  44
  45   registerMetrics (options: { trackerServer: any }) {
  46     if (CONFIG.OPEN_TELEMETRY.METRICS.ENABLED !== true) return
  47
  48     logger.info('Registering Open Telemetry metrics')
  49
  50     const provider = new MeterProvider({
  51       views: [
  52         ...NodeJSObserversBuilder.getViews()
  53       ]
  54     })
  55
  56     provider.addMetricReader(new PrometheusExporter({
  57       host: CONFIG.OPEN_TELEMETRY.METRICS.PROMETHEUS_EXPORTER.HOSTNAME,
  58       port: CONFIG.OPEN_TELEMETRY.METRICS.PROMETHEUS_EXPORTER.PORT
  59     }))
  60
  61     metrics.setGlobalMeterProvider(provider)
  62
  63     this.meter = metrics.getMeter('default')
  64
  65     this.buildRequestObserver()
  66
  67     this.playbackMetrics = new PlaybackMetrics(this.meter)
  68     this.playbackMetrics.buildCounters()
  69
  70     const nodeJSObserversBuilder = new NodeJSObserversBuilder(this.meter)
  71     nodeJSObserversBuilder.buildObservers()
  72
  73     const jobQueueObserversBuilder = new JobQueueObserversBuilder(this.meter)
  74     jobQueueObserversBuilder.buildObservers()
  75
  76     const statsObserversBuilder = new StatsObserversBuilder(this.meter)
  77     statsObserversBuilder.buildObservers()
  78
  79     const livesObserversBuilder = new LivesObserversBuilder(this.meter)
  80     livesObserversBuilder.buildObservers()
  81
  82     const viewersObserversBuilder = new ViewersObserversBuilder(this.meter)
  83     viewersObserversBuilder.buildObservers()
  84
  85     const bittorrentTrackerObserversBuilder = new BittorrentTrackerObserversBuilder(this.meter, options.trackerServer)
  86     bittorrentTrackerObserversBuilder.buildObservers()
  87   }
  88
  89   observePlaybackMetric (video: MVideoImmutable, metrics: PlaybackMetricCreate) {
  90     this.playbackMetrics.observe(video, metrics)
  91   }
  92
  93   private buildRequestObserver () {
  94     const requestDuration = this.meter.createHistogram('http_request_duration_ms', {
  95       unit: 'milliseconds',
  96       description: 'Duration of HTTP requests in ms'
  97     })
  98
  99     this.onRequestDuration = (req: Request, res: Response) => {
 100       const duration = Date.now() - res.locals.requestStart
 101
 102       requestDuration.record(duration, {
 103         path: this.buildRequestPath(req.originalUrl),
 104         method: req.method,
 105         statusCode: res.statusCode + ''
 106       })
 107     }
 108   }
 109
 110   private buildRequestPath (path: string) {
 111     return path.split('?')[0]
 112   }
 113
 114   static get Instance () {
 115     return this.instance || (this.instance = new this())
 116   }
 117 }
 118
 119 export {
 120   OpenTelemetryMetrics
 121 }