surfer.go

// Copyright 2015 Google Inc. All Rights Reserved.
//
// 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.

// Command surfer scrapes the signal status page of the following cable
// modems and exports values as prometheus metrics.
// * SB6121
// * SB6183
// * SB8200

package main

import (
	"context"
	"crypto/tls"
	"flag"
	"net/http"
	_ "net/http/pprof"
	"strconv"
	"time"

	"github.com/golang/glog"
	"github.com/golang/groupcache/singleflight"
	"github.com/prometheus/client_golang/prometheus"
	"github.com/prometheus/client_golang/prometheus/promhttp"

	"github.com/wathiede/surfer/modem"
	_ "github.com/wathiede/surfer/modem/sb6121"
	_ "github.com/wathiede/surfer/modem/sb6183"
	_ "github.com/wathiede/surfer/modem/sb8200"
)

var (
	port                  = flag.Int("port", 6666, "port to listen on when serving prometheus metrics")
	timeout               = flag.Duration("timeout", 1*time.Second, "timeout for the HTTP GET to cable modem")
	fakeDataPath          = flag.String("fake", "", "path to fake HTML data.  (default) fetch over HTTP")
	tlsInsecureSkipVerify = flag.Bool("tls_insecure_skip_verify", false, "Whether to verify TLS certs")

	downstreamSNRMetric = prometheus.NewGaugeVec(prometheus.GaugeOpts{
		Name: "downstream_snr",
		Help: "Downstream signal-to-noise ratio in dB",
	},
		[]string{"channel", "frequency_hz", "modulation"},
	)
	downstreamPowerLevelMetric = prometheus.NewGaugeVec(prometheus.GaugeOpts{
		Name: "downstream_power_level",
		Help: "Downstream power level reading in dBmV",
	},
		[]string{"channel", "frequency_hz", "modulation"},
	)

	codewordsUnerroredMetric = prometheus.NewGaugeVec(prometheus.GaugeOpts{
		Name: "codewords_unerrored",
		Help: "Unerrored codeword count",
	},
		[]string{"channel"},
	)
	codewordsCorrectableMetric = prometheus.NewGaugeVec(prometheus.GaugeOpts{
		Name: "codewords_correctable",
		Help: "Correctable codeword count",
	},
		[]string{"channel"},
	)
	codewordsUncorrectableMetric = prometheus.NewGaugeVec(prometheus.GaugeOpts{
		Name: "codewords_uncorrectable",
		Help: "Uncorrectable codeword count",
	},
		[]string{"channel"},
	)

	upstreamSymbolRateMetric = prometheus.NewGaugeVec(prometheus.GaugeOpts{
		Name: "upstream_symbol_rate",
		Help: "Upstream symbol rate in sym/sec",
	},
		[]string{"channel", "frequency_hz", "modulation", "ranging_status"},
	)
	upstreamPowerLevelMetric = prometheus.NewGaugeVec(prometheus.GaugeOpts{
		Name: "upstream_power_level",
		Help: "Upstream power level reading in dBmV",
	},
		[]string{"channel", "frequency_hz", "modulation", "ranging_status"},
	)

	fetchErrorsMetric = prometheus.NewGauge(prometheus.GaugeOpts{
		Name: "fetch_errors",
		Help: "Count of errors when fetching metrics from modem.",
	})

	fetchSuccessesMetric = prometheus.NewGauge(prometheus.GaugeOpts{
		Name: "fetch_successes",
		Help: "Count of successes when fetching metrics from modem.",
	})
)

func init() {
	prometheus.MustRegister(downstreamSNRMetric)
	prometheus.MustRegister(downstreamPowerLevelMetric)
	prometheus.MustRegister(upstreamSymbolRateMetric)
	prometheus.MustRegister(upstreamPowerLevelMetric)
	prometheus.MustRegister(codewordsUnerroredMetric)
	prometheus.MustRegister(codewordsCorrectableMetric)
	prometheus.MustRegister(codewordsUncorrectableMetric)
	prometheus.MustRegister(fetchErrorsMetric)
	prometheus.MustRegister(fetchSuccessesMetric)
}

func main() {
	flag.Parse()
	defer glog.Flush()
	client := &http.Client{
		Transport: &http.Transport{
			TLSClientConfig: &tls.Config{
				InsecureSkipVerify: *tlsInsecureSkipVerify,
			},
		},
		Timeout: 10 * time.Second,
	}

	ctx := context.Background()
	var m modem.Modem
	for {
		ctx, cancel := context.WithTimeout(ctx, *timeout)
		m = modem.New(ctx, *client, *fakeDataPath)
		cancel()
		if m != nil {
			break
		}
		glog.Infof("Failed to find modem, sleeping")
		time.Sleep(5 * time.Second)
	}
	glog.Infof("Found modem %q", m.Name())

	g := &singleflight.Group{}
	ph := promhttp.Handler()
	// Refresh data every prometheus poll.
	http.Handle("/metrics", http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		// Only make one query to the cable modem if concurrent requests come in.
		if _, err := g.Do("get", func() (interface{}, error) {
			ctx, cancel := context.WithTimeout(ctx, *timeout)
			defer cancel()
			s, err := m.Status(ctx, *client)
			if err != nil {
				fetchErrorsMetric.Inc()
				return nil, err
			}
			for ch, d := range s.Downstream {
				downstreamSNRMetric.WithLabelValues(string(ch), d.Frequency, d.Modulation).Set(d.SNR)
				downstreamPowerLevelMetric.WithLabelValues(string(ch), d.Frequency, d.Modulation).Set(d.PowerLevel)
				codewordsUnerroredMetric.WithLabelValues(string(ch)).Set(d.Unerrored)
				codewordsCorrectableMetric.WithLabelValues(string(ch)).Set(d.Correctable)
				codewordsUncorrectableMetric.WithLabelValues(string(ch)).Set(d.Uncorrectable)
			}

			for ch, u := range s.Upstream {
				upstreamSymbolRateMetric.WithLabelValues(string(ch), u.Frequency, u.Modulation, u.Status).Set(u.SymbolRate)
				upstreamPowerLevelMetric.WithLabelValues(string(ch), u.Frequency, u.Modulation, u.Status).Set(u.PowerLevel)
			}
			fetchSuccessesMetric.Inc()
			return nil, nil
		}); err != nil {
			http.Error(w, err.Error(), http.StatusInternalServerError)
			return
		}
		ph.ServeHTTP(w, r)
	}))
	glog.Fatalf("Listener returned: %v", http.ListenAndServe(":"+strconv.Itoa(*port), nil))
}