collector.go

/*
 *    Copyright 2020 Yury Makarov
 *
 *    Licensed under the Apache License, Version 2.0 (the "License");
 *    you may not use this file except in compliance with the License.
 *    You may obtain a copy of the License at
 *
 *        http://www.apache.org/licenses/LICENSE-2.0
 *
 *    Unless required by applicable law or agreed to in writing, software
 *    distributed under the License is distributed on an "AS IS" BASIS,
 *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *    See the License for the specific language governing permissions and
 *    limitations under the License.
 *
 */

package collector

import (
	"github.com/mef13/flussonic_exporter/flussonic"
	"github.com/mef13/flussonic_exporter/logger"
	"github.com/prometheus/client_golang/prometheus"
	"github.com/robfig/cron/v3"
	"go.uber.org/zap"
	"sync"
	"time"
)

const namespace = "flussonic"

var (
	scrapeDurationDesc = prometheus.NewDesc(
		prometheus.BuildFQName(namespace, `scrape`, `collector_duration_seconds`),
		`flussonic_exporter: Duration of a collector scrape.`,
		[]string{`server`},
		nil,
	)
	scrapeSuccessDesc = prometheus.NewDesc(
		prometheus.BuildFQName(namespace, `scrape`, `collector_success`),
		`flussonic_exporter: Whether a collector succeeded.`,
		[]string{`server`},
		nil,
	)

	totalClientsDesc = prometheus.NewDesc(
		prometheus.BuildFQName(namespace, `clients`, `total`),
		`flussonic_exporter: Total clients count.`,
		[]string{`server`},
		prometheus.Labels{"type": "total"},
	)
	totalDvrClientsDesc = prometheus.NewDesc(
		prometheus.BuildFQName(namespace, `clients`, `total`),
		`flussonic_exporter: Total clients count.`,
		[]string{`server`},
		prometheus.Labels{"type": "dvr"},
	)
	requestDurationDesc = prometheus.NewDesc(
		prometheus.BuildFQName(namespace, `scrape`, `api_request_duration_sec`),
		`flussonic_exporter: API request duration.`,
		[]string{`server`, `url`},
		nil,
	)

	streamLabels      = []string{`server`, `name`, `title`, `comment`, `dvr_enabled`, `transcoder_enabled`}
	streamBitrateDesc = prometheus.NewDesc(
		prometheus.BuildFQName(namespace, `stream`, `bitrate`),
		`flussonic_exporter: Stream bitrate.`,
		streamLabels,
		nil,
	)
	streamRetryCountDesc = prometheus.NewDesc(
		prometheus.BuildFQName(namespace, `stream`, `retry_count`),
		`flussonic_exporter: Stream retry count.`,
		streamLabels,
		nil,
	)
	streamAliveDesc = prometheus.NewDesc(
		prometheus.BuildFQName(namespace, `stream`, `is_alive`),
		`flussonic_exporter: Is stream alive.`,
		streamLabels,
		nil,
	)
	streamInputErrorRateDesc = prometheus.NewDesc(
		prometheus.BuildFQName(namespace, `stream`, `input_error_rate`),
		`flussonic_exporter: Stream input error rate.`,
		streamLabels,
		nil,
	)
	streamTracksCountDesc = prometheus.NewDesc(
		prometheus.BuildFQName(namespace, `stream`, `tracks_count`),
		`flussonic_exporter: Stream tracks count.`,
		streamLabels,
		nil,
	)
	streamClientsTotalDesc = prometheus.NewDesc(
		prometheus.BuildFQName(namespace, `stream`, `clients_count`),
		`flussonic_exporter: Stream clients count.`,
		streamLabels,
		prometheus.Labels{"type": "total"},
	)
	streamClientsDvrDesc = prometheus.NewDesc(
		prometheus.BuildFQName(namespace, `stream`, `clients_count`),
		`flussonic_exporter: Stream clients count.`,
		streamLabels,
		prometheus.Labels{"type": "dvr"},
	)
)

type FlussonicCollector struct {
	cache map[string]*flussonicCollectorCache
}

type flussonicCollectorCache struct {
	cache []prometheus.Metric
	sync  sync.RWMutex
}

// Describe implements the prometheus.Collector interface.
func (c *FlussonicCollector) Describe(ch chan<- *prometheus.Desc) {
	ch <- scrapeSuccessDesc
	ch <- scrapeDurationDesc
}

// Collect implements the prometheus.Collector interface.
func (c *FlussonicCollector) Collect(ch chan<- prometheus.Metric) {
	for flussonicUrl := range c.cache {
		send(ch, c.cache[flussonicUrl])
	}
}

func send(ch chan<- prometheus.Metric, cache *flussonicCollectorCache) {
	cache.sync.RLock()
	defer cache.sync.RUnlock()
	for _, metric := range cache.cache {
		ch <- metric
	}
}

func NewCollector() *FlussonicCollector {
	return &FlussonicCollector{cache: make(map[string]*flussonicCollectorCache)}
}

func (c *flussonicCollectorCache) addMetric(m prometheus.Metric) {
	c.cache = append(c.cache, m)
}

func (c *FlussonicCollector) save(flussonicUrl string, cache *flussonicCollectorCache) {
	_, ok := c.cache[flussonicUrl]
	if ok {
		c.cache[flussonicUrl].sync.Lock()
		defer c.cache[flussonicUrl].sync.Unlock()
	}
	c.cache[flussonicUrl] = cache
}

func (c *FlussonicCollector) failScrape(flussConf flussonic.Flussonic, startTime time.Time) {
	cache := &flussonicCollectorCache{}
	cache.addMetric(prometheus.MustNewConstMetric(scrapeSuccessDesc, prometheus.GaugeValue, float64(0),
		flussConf.InstanceName))
	duration := time.Since(startTime)
	cache.addMetric(prometheus.MustNewConstMetric(scrapeDurationDesc, prometheus.GaugeValue, duration.Seconds(),
		flussConf.InstanceName))
	c.save(flussConf.Url.String(), cache)
}

func (c *FlussonicCollector) Scrape(flussConf flussonic.Flussonic) {
	logger.Debug("start scrapping", zap.String("instance", flussConf.InstanceName))
	startTime := time.Now()
	cache := &flussonicCollectorCache{}

	//get metrics
	serv, err := flussConf.GetServer()
	if err != nil {
		logger.Error("error scrape from flussonic api",
			zap.String("server", flussConf.Url.String()), zap.String("method", "GetServer"), zap.Error(err))
		c.failScrape(flussConf, startTime)
		return
	}
	media, err := flussConf.GetMedia()
	if err != nil {
		logger.Error("error scrape from flussonic api",
			zap.String("server", flussConf.Url.String()), zap.String("method", "GetMedia"), zap.Error(err))
		c.failScrape(flussConf, startTime)
		return
	}
	sessions, err := flussConf.GetSessions()
	if err != nil {
		logger.Error("error scrape from flussonic api",
			zap.String("server", flussConf.Url.String()), zap.String("method", "GetSessions"), zap.Error(err))
		c.failScrape(flussConf, startTime)
		return
	}

	//add metrics to cache
	cache.addMetric(prometheus.MustNewConstMetric(
		requestDurationDesc,
		prometheus.GaugeValue,
		serv.RequestDuration,
		flussConf.InstanceName,
		serv.Url,
	))
	cache.addMetric(prometheus.MustNewConstMetric(
		requestDurationDesc,
		prometheus.GaugeValue,
		media.RequestDuration,
		flussConf.InstanceName,
		media.Url,
	))
	cache.addMetric(prometheus.MustNewConstMetric(
		requestDurationDesc,
		prometheus.GaugeValue,
		sessions.RequestDuration,
		flussConf.InstanceName,
		sessions.Url,
	))
	cache.addMetric(prometheus.MustNewConstMetric(
		totalClientsDesc,
		prometheus.GaugeValue,
		serv.TotalClients,
		flussConf.InstanceName,
	))
	cache.addMetric(prometheus.MustNewConstMetric(
		totalDvrClientsDesc,
		prometheus.GaugeValue,
		sessions.TotalDvrClients,
		flussConf.InstanceName,
	))

	//add streams
	for _, stream := range media.Streams {
		cache.addMetric(newStreamGaugeMetric(
			streamBitrateDesc,
			stream.Stats.Bitrate,
			flussConf.InstanceName,
			stream,
		))
		cache.addMetric(newStreamCounterMetric(
			streamRetryCountDesc,
			stream.Stats.RetryCount,
			flussConf.InstanceName,
			stream,
		))
		isAlive := float64(0)
		if stream.Stats.Alive {
			isAlive = 1
		}
		cache.addMetric(newStreamGaugeMetric(
			streamAliveDesc,
			isAlive,
			flussConf.InstanceName,
			stream,
		))
		cache.addMetric(newStreamGaugeMetric(
			streamInputErrorRateDesc,
			stream.Stats.InputErrorRate,
			flussConf.InstanceName,
			stream,
		))
		cache.addMetric(newStreamGaugeMetric(
			streamTracksCountDesc,
			float64(len(stream.Stats.MediaInfo.Tracks)),
			flussConf.InstanceName,
			stream,
		))
		session, ok := sessions.Sessions[stream.Name]
		if !ok {
			session = &flussonic.MediaSessions{
				Name:         stream.Name,
				DvrClients:   0,
				TotalClients: 0,
				Types:        nil,
			}
		}
		cache.addMetric(newStreamGaugeMetric(
			streamClientsTotalDesc,
			session.TotalClients,
			flussConf.InstanceName,
			stream,
		))
		cache.addMetric(newStreamGaugeMetric(
			streamClientsDvrDesc,
			session.DvrClients,
			flussConf.InstanceName,
			stream,
		))
	}

	//end scrape & save cache
	cache.addMetric(prometheus.MustNewConstMetric(scrapeSuccessDesc, prometheus.GaugeValue, float64(1),
		flussConf.InstanceName))
	duration := time.Since(startTime)
	cache.addMetric(prometheus.MustNewConstMetric(scrapeDurationDesc, prometheus.GaugeValue, duration.Seconds(),
		flussConf.InstanceName))
	c.save(flussConf.Url.String(), cache)
}

func newStreamMetric(desc *prometheus.Desc, valueType prometheus.ValueType, value float64, instanceName string, stream *flussonic.Stream) prometheus.Metric {
	dvrEnabled := "0"
	if stream.Stats.DvrEnabled {
		dvrEnabled = "1"
	}
	transcoderEnabled := "0"
	if stream.Stats.RunningTranscoder {
		transcoderEnabled = "1"
	}
	return prometheus.MustNewConstMetric(
		desc,
		valueType,
		value,
		instanceName,
		stream.Name,
		stream.Options.Title,
		stream.Options.Comment,
		dvrEnabled,
		transcoderEnabled,
	)
}

func newStreamGaugeMetric(desc *prometheus.Desc, value float64, instanceName string, stream *flussonic.Stream) prometheus.Metric {
	return newStreamMetric(desc, prometheus.GaugeValue, value, instanceName, stream)
}

func newStreamCounterMetric(desc *prometheus.Desc, value float64, instanceName string, stream *flussonic.Stream) prometheus.Metric {
	return newStreamMetric(desc, prometheus.CounterValue, value, instanceName, stream)
}

// FuncJob is a wrapper that turns a func() into a cron.Job
type FuncJob struct {
	f         func(flussConf flussonic.Flussonic)
	flussConf flussonic.Flussonic
}

func (f FuncJob) Run() { f.f(f.flussConf) }

func (c *FlussonicCollector) GetCronJob(flussConf flussonic.Flussonic) cron.Job {
	return FuncJob{
		f:         c.Scrape,
		flussConf: flussConf,
	}
}