From 2ea8ca84476a8302ad6f51acd33b2fcf0fb2ede7 Mon Sep 17 00:00:00 2001
From: Steve Brunton <brunton@dudeman.com>
Date: Tue, 28 Nov 2017 23:58:39 -0500
Subject: [PATCH] re-worked to actually properly work at collecting metrics

---
 collector/collector.go  |  77 ++++++++++++++++++++
 collector/config.go     |  14 ++--
 collector/device.go     | 151 +++++++++++++++++++++++++---------------
 collector/prometheus.go |  26 ++-----
 main.go                 |  85 +++++++++++++++-------
 5 files changed, 244 insertions(+), 109 deletions(-)

diff --git a/collector/collector.go b/collector/collector.go
index 66f94de..99fd217 100644
--- a/collector/collector.go
+++ b/collector/collector.go
@@ -1 +1,78 @@
 package collector
+
+import (
+	"sync"
+	"time"
+
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/common/log"
+)
+
+const namespace = "mikrotik"
+
+var (
+	scrapeDurationDesc = prometheus.NewDesc(
+		prometheus.BuildFQName(namespace, "scrape", "collector_duration_seconds"),
+		"mikrotik_exporter: duration of a collector scrape",
+		[]string{"device"},
+		nil,
+	)
+	scrapeSuccessDesc = prometheus.NewDesc(
+		prometheus.BuildFQName(namespace, "scrape", "collector_success"),
+		"mikrotik_exporter: whether a collector succeeded",
+		[]string{"device"},
+		nil,
+	)
+)
+
+type deviceCollector struct {
+	Devices []Device
+}
+
+func NewDeviceCollector(cfg Config) (*deviceCollector, error) {
+	devices := make([]Device, len(cfg.Devices))
+
+	cfg.Logger.Info("setting up collector for devices",
+		"numDevices", len(cfg.Devices),
+	)
+
+	copy(devices, cfg.Devices)
+
+	return &deviceCollector{Devices: devices}, nil
+}
+
+// Describe implements the prometheus.Collector interface.
+func (d deviceCollector) Describe(ch chan<- *prometheus.Desc) {
+	ch <- scrapeDurationDesc
+	ch <- scrapeSuccessDesc
+}
+
+// Collect implements the prometheus.Collector interface.
+func (d deviceCollector) Collect(ch chan<- prometheus.Metric) {
+	wg := sync.WaitGroup{}
+	wg.Add(len(d.Devices))
+	for _, device := range d.Devices {
+		go func(d Device) {
+			execute(d, ch)
+			wg.Done()
+		}(device)
+	}
+	wg.Wait()
+}
+
+func execute(d Device, ch chan<- prometheus.Metric) {
+	begin := time.Now()
+	err := d.Update(ch)
+	duration := time.Since(begin)
+	var success float64
+
+	if err != nil {
+		log.Errorf("ERROR: %s collector failed after %fs: %s", d.name, duration.Seconds(), err)
+		success = 0
+	} else {
+		log.Debugf("OK: %s collector succeeded after %fs.", d.name, duration.Seconds())
+		success = 1
+	}
+	ch <- prometheus.MustNewConstMetric(scrapeDurationDesc, prometheus.GaugeValue, duration.Seconds(), d.name)
+	ch <- prometheus.MustNewConstMetric(scrapeSuccessDesc, prometheus.GaugeValue, success, d.name)
+}
diff --git a/collector/config.go b/collector/config.go
index 1d7d43b..7f8a014 100644
--- a/collector/config.go
+++ b/collector/config.go
@@ -1,7 +1,9 @@
-package exporter
+package collector
 
 import (
 	"fmt"
+
+	"github.com/prometheus/client_golang/prometheus"
 	"go.uber.org/zap"
 )
 
@@ -17,10 +19,12 @@ func (c *Config) FromFlags(device, address, user, password *string) error {
 	}
 
 	d := &Device{
-		Address:  *address,
-		Name:     *device,
-		User:     *user,
-		Password: *password,
+		address:  *address,
+		name:     *device,
+		user:     *user,
+		password: *password,
+		iDesc:    map[string]*prometheus.Desc{},
+		rDesc:    map[string]*prometheus.Desc{},
 	}
 
 	*c = Config{
diff --git a/collector/device.go b/collector/device.go
index 86e253b..a51884c 100644
--- a/collector/device.go
+++ b/collector/device.go
@@ -1,81 +1,118 @@
-package exporter
+package collector
 
 import (
-	"go.uber.org/zap"
-	"gopkg.in/routeros.v2"
-	"strconv"
 	"strings"
+
+	"fmt"
+
+	"strconv"
+
+	"github.com/prometheus/client_golang/prometheus"
+	"gopkg.in/routeros.v2"
+	"gopkg.in/routeros.v2/proto"
 )
 
 const (
 	apiPort = ":8728"
 )
 
+var (
+	interfaceLabelNames = []string{"name", "address", "interface"}
+	InterfaceProps      = []string{"name", "rx-byte", "tx-byte", "rx-packet", "tx-packet", "rx-error", "tx-error", "rx-drop", "tx-drop"}
+	resourceLabelNames  = []string{"name", "address"}
+	ResourceProps       = []string{"free-memory", "total-memory", "cpu-load", "free-hdd-space", "total-hdd-space"}
+)
+
 type Device struct {
-	Address  string
-	Name     string
-	User     string
-	Password string
+	address  string
+	name     string
+	user     string
+	password string
+	iDesc    map[string]*prometheus.Desc // interface level descriptions for device
+	rDesc    map[string]*prometheus.Desc // resource level descriptions for device
 }
 
-func (d *Device) fetchInterfaceMetrics(c *routeros.Client, m PromMetrics, l *zap.SugaredLogger) error {
-	l.Debugw("fetching interface metrics",
-		"device", d.Name,
-	)
+func metricStringCleanup(in string) string {
+	return strings.Replace(in, "-", "_", -1)
+}
+
+func (d *Device) fetchInterfaceMetrics() ([]*proto.Sentence, error) {
+	// clean up logging later TODO(smb)
+	//l.Debugw("fetching interface metrics",
+	//	"device", d.name,
+	//)
+
+	// grab a connection to the device
+	c, err := routeros.Dial(d.address+apiPort, d.user, d.password)
+	if err != nil {
+		// clean up logging later TODO(smb)
+		//l.Errorw("error dialing device",
+		//	"device", d.name,
+		//	"error", err,
+		//)
+		return nil, err
+	}
+	defer c.Close()
 
 	reply, err := c.Run("/interface/print", "?disabled=false",
 		"?running=true", "=.proplist="+strings.Join(InterfaceProps, ","))
 	if err != nil {
-		return err
+		// do some logging here about an error when we redo all the logging TODO(smb)
+		return nil, err
 	}
 
-	for _, re := range reply.Re {
-		var name string
-		// name should always be first element on the array
-		for _, p := range InterfaceProps {
-			if p == "name" {
-				name = re.Map[p]
-			} else {
-				v, err := strconv.ParseFloat(re.Map[p], 64)
-				if err != nil {
-					l.Errorw("error parsing value to float",
-						"device", d.Name,
-						"property", p,
-						"value", re.Map[p],
-						"error", err,
-					)
+	return reply.Re, nil
+
+	//for _, re := range reply.Re {
+	//	var name string
+	//	// name should always be first element on the array
+	//	for _, p := range InterfaceProps {
+	//		if p == "name" {
+	//			name = re.Map[p]
+	//		} else {
+	//			v, err := strconv.ParseFloat(re.Map[p], 64)
+	//			if err != nil {
+	//				l.Errorw("error parsing value to float",
+	//					"device", d.name,
+	//					"property", p,
+	//					"value", re.Map[p],
+	//					"error", err,
+	//				)
+	//			}
+	//			m.IncrementInterface(p, d.name, d.address, name, v)
+	//		}
+	//	}
+	//}
+}
+
+func (d *Device) Update(ch chan<- prometheus.Metric) error {
+
+	stats, err := d.fetchInterfaceMetrics()
+	// if there is no error, deal with the response
+	if err == nil {
+		for _, re := range stats {
+			var intf string
+			for _, p := range InterfaceProps {
+				if p == "name" {
+					intf = re.Map[p]
+				} else {
+					desc, ok := d.iDesc[p]
+					if !ok {
+						desc = prometheus.NewDesc(
+							prometheus.BuildFQName(namespace, "interface", metricStringCleanup(p)),
+							fmt.Sprintf("interface property statistic %s", p),
+							interfaceLabelNames,
+							nil,
+						)
+						d.iDesc[p] = desc
+					}
+					v, err := strconv.ParseFloat(re.Map[p], 64)
+					if err == nil {
+						ch <- prometheus.MustNewConstMetric(desc, prometheus.CounterValue, v, d.name, d.address, intf)
+					} // add an else with logging here when logging is re done TODO(smb)
 				}
-				m.IncrementInterface(p, d.Name, d.Address, name, v)
 			}
 		}
 	}
-
-	l.Debugw("done fetching interface metrics",
-		"device", d.Name,
-	)
-
-	return nil
-}
-
-func (d *Device) CollectMetrics(p PromMetrics, l *zap.SugaredLogger) error {
-
-	c, err := routeros.Dial(d.Address+apiPort, d.User, d.Password)
-	if err != nil {
-		l.Errorw("error dialing device",
-			"device", d.Name,
-			"error", err,
-		)
-		return err
-	}
-	defer c.Close()
-
-	if err := d.fetchInterfaceMetrics(c, p, l); err != nil {
-		l.Errorw("error fetching interface metrics",
-			"device", d.Name,
-			"error", err,
-		)
-		return err
-	}
-
 	return nil
 }
diff --git a/collector/prometheus.go b/collector/prometheus.go
index 90298f5..a39408c 100644
--- a/collector/prometheus.go
+++ b/collector/prometheus.go
@@ -1,24 +1,12 @@
-package exporter
+package collector
 
 import (
-	"strings"
-
 	"fmt"
+	"net/http"
+
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/client_golang/prometheus/promhttp"
 	"go.uber.org/zap"
-	"net/http"
-)
-
-const (
-	promNamespace = "mikrotik"
-)
-
-var (
-	interfaceLabelNames = []string{"name", "address", "interface"}
-	InterfaceProps      = []string{"name", "rx-byte", "tx-byte", "rx-packet", "tx-packet", "rx-error", "tx-error", "rx-drop", "tx-drop"}
-	resourceLabelNames  = []string{"name", "address"}
-	ResourceProps       = []string{"free-memory", "total-memory", "cpu-load", "free-hdd-space", "total-hdd-space"}
 )
 
 type PromMetrics struct {
@@ -26,10 +14,6 @@ type PromMetrics struct {
 	ResourceMetrics  map[string]*prometheus.GaugeVec
 }
 
-func metricStringCleanup(in string) string {
-	return strings.Replace(in, "-", "_", -1)
-}
-
 func (p *PromMetrics) makeLabels(name, address string) prometheus.Labels {
 	labels := make(prometheus.Labels)
 	labels["name"] = metricStringCleanup(name)
@@ -51,7 +35,7 @@ func (p *PromMetrics) SetupPrometheus(l zap.SugaredLogger) (http.Handler, error)
 	for _, v := range InterfaceProps {
 		n := metricStringCleanup(v)
 		c := prometheus.NewCounterVec(prometheus.CounterOpts{
-			Namespace: promNamespace,
+			Namespace: namespace,
 			Subsystem: "interface",
 			Name:      n,
 			Help:      fmt.Sprintf("Interface %s counter", v),
@@ -72,7 +56,7 @@ func (p *PromMetrics) SetupPrometheus(l zap.SugaredLogger) (http.Handler, error)
 	for _, v := range ResourceProps {
 		n := metricStringCleanup(v)
 		c := prometheus.NewGaugeVec(prometheus.GaugeOpts{
-			Namespace: promNamespace,
+			Namespace: namespace,
 			Subsystem: "resource",
 			Name:      n,
 			Help:      fmt.Sprintf("Resource %s counter", v),
diff --git a/main.go b/main.go
index 7bb992d..d816cb5 100644
--- a/main.go
+++ b/main.go
@@ -3,10 +3,15 @@ package main
 import (
 	"flag"
 	"os"
-	"os/signal"
 
-	"github.com/nshttpd/mikrotik-exporter/exporter"
+	"fmt"
+	"net/http"
+
+	"github.com/nshttpd/mikrotik-exporter/collector"
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promhttp"
 	"github.com/prometheus/common/log"
+	"github.com/prometheus/common/version"
 	"go.uber.org/zap"
 )
 
@@ -19,10 +24,45 @@ var (
 	cfgFile         = flag.String("config", "", "config file for multiple devices")
 	logLevel        = flag.String("log-level", "info", "log level")
 	port            = flag.String("port", ":9090", "port number to listen on")
+	metricsPath     = flag.String("path", "/metrics", "path to answer requests on")
 	currentLogLevel = zap.NewAtomicLevelAt(zap.InfoLevel)
+	cfg             collector.Config
 )
 
-// (nshttpd) TODO figure out if we need a caching option
+func init() {
+	prometheus.MustRegister(version.NewCollector("mikrotik_exporter"))
+}
+
+func handler(w http.ResponseWriter, r *http.Request) {
+	nc, err := collector.NewDeviceCollector(cfg)
+	if err != nil {
+		log.Warnln("Couldn't create", err)
+		w.WriteHeader(http.StatusBadRequest)
+		w.Write([]byte(fmt.Sprintf("Couldn't create %s", err)))
+		return
+	}
+
+	registry := prometheus.NewRegistry()
+	err = registry.Register(nc)
+	if err != nil {
+		log.Errorln("Couldn't register collector:", err)
+		w.WriteHeader(http.StatusInternalServerError)
+		w.Write([]byte(fmt.Sprintf("Couldn't register collector: %s", err)))
+		return
+	}
+
+	gatherers := prometheus.Gatherers{
+		prometheus.DefaultGatherer,
+		registry,
+	}
+	// Delegate http serving to Prometheus client library, which will call collector.Collect.
+	h := promhttp.HandlerFor(gatherers,
+		promhttp.HandlerOpts{
+			ErrorLog:      log.NewErrorLogger(),
+			ErrorHandling: promhttp.ContinueOnError,
+		})
+	h.ServeHTTP(w, r)
+}
 
 func main() {
 	flag.Parse()
@@ -42,7 +82,6 @@ func main() {
 	}
 	defer l.Sync()
 
-	var cfg exporter.Config
 	if *cfgFile == "" {
 		if err := cfg.FromFlags(device, address, user, password); err != nil {
 			l.Sugar().Errorw("could not create configuration",
@@ -57,32 +96,26 @@ func main() {
 
 	cfg.Logger = l.Sugar()
 
-	cfg.Metrics = exporter.PromMetrics{}
-	mh, err := cfg.Metrics.SetupPrometheus(*cfg.Logger)
+	http.HandleFunc(*metricsPath, prometheus.InstrumentHandlerFunc("prometheus", handler))
+	http.HandleFunc("/healthz", func(w http.ResponseWriter, r *http.Request) {
+		w.Write([]byte("ok"))
+	})
+	http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
+		w.Write([]byte(`<html>
+			<head><title>Mikrotik Exporter</title></head>
+			<body>
+			<h1>Mikrotik Exporter</h1>
+			<p><a href="` + *metricsPath + `">Metrics</a></p>
+			</body>
+			</html>`))
+	})
+
+	log.Infoln("Listening on", *port)
+	err = http.ListenAndServe(*port, nil)
 	if err != nil {
 		log.Fatal(err)
 	}
 
-	s := &exporter.Server{}
-
-	if err := s.Run(cfg, mh, port); err != nil {
-		log.Fatal(err)
-	}
-
-	sigchan := make(chan os.Signal, 1)
-	signal.Notify(sigchan, os.Interrupt, os.Kill)
-	<-sigchan
-	cfg.Logger.Info("stopping server")
-	err = s.Stop()
-	if err != nil {
-		cfg.Logger.Errorw("error while stopping service",
-			"error", err,
-		)
-		os.Exit(1)
-	}
-
-	os.Exit(0)
-
 }
 
 func newLogger(lvl zap.AtomicLevel) (*zap.Logger, error) {