PoE collector (#54)

Thanks for the PR.

* PoE collector
* Correcting mistake in comment for WithPOE function

collector/collector.go

@@ -84,6 +84,13 @@ func WithDHCPv6() Option {
 	}
 }
 
+// WithPOE enables PoE metrics
+func WithPOE() Option {
+	return func(c *collector) {
+		c.collectors = append(c.collectors, newPOECollector())
+	}
+}
+
 // WithPools enables IP(v6) pool metrics
 func WithPools() Option {
 	return func(c *collector) {

collector/poe_collector.go

@@ -0,0 +1,122 @@
+package collector
+
+import (
+	"strconv"
+	"strings"
+
+	"github.com/prometheus/client_golang/prometheus"
+	log "github.com/sirupsen/logrus"
+	"gopkg.in/routeros.v2/proto"
+)
+
+type poeCollector struct {
+	currentDesc *prometheus.Desc
+	powerDesc   *prometheus.Desc
+	voltageDesc *prometheus.Desc
+	props       []string
+}
+
+func newPOECollector() routerOSCollector {
+	const prefix = "poe"
+
+	labelNames := []string{"name", "address", "interface"}
+	return &poeCollector{
+		currentDesc: description(prefix, "current", "current in mA", labelNames),
+		powerDesc:   description(prefix, "wattage", "Power in W", labelNames),
+		voltageDesc: description(prefix, "voltage", "Voltage in V", labelNames),
+		props:       []string{"poe-out-current", "poe-out-voltage", "poe-out-power"},
+	}
+}
+
+func (c *poeCollector) describe(ch chan<- *prometheus.Desc) {
+	ch <- c.currentDesc
+	ch <- c.powerDesc
+	ch <- c.voltageDesc
+}
+
+func (c *poeCollector) collect(ctx *collectorContext) error {
+	reply, err := ctx.client.Run("/interface/ethernet/poe/print", "=.proplist=name")
+	if err != nil {
+		log.WithFields(log.Fields{
+			"device": ctx.device.Name,
+			"error":  err,
+		}).Error("error fetching interface poe metrics")
+		return err
+	}
+
+	ifaces := make([]string, 0)
+	for _, iface := range reply.Re {
+		n := iface.Map["name"]
+		ifaces = append(ifaces, n)
+	}
+
+	if len(ifaces) == 0 {
+		return nil
+	}
+
+	return c.collectPOEMetricsForInterfaces(ifaces, ctx)
+}
+
+func (c *poeCollector) collectPOEMetricsForInterfaces(ifaces []string, ctx *collectorContext) error {
+	reply, err := ctx.client.Run("/interface/ethernet/poe/monitor",
+		"=numbers="+strings.Join(ifaces, ","),
+		"=once=",
+		"=.proplist=name,"+strings.Join(c.props, ","))
+	if err != nil {
+		log.WithFields(log.Fields{
+			"device": ctx.device.Name,
+			"error":  err,
+		}).Error("error fetching interface poe monitor metrics")
+		return err
+	}
+
+	for _, se := range reply.Re {
+		name, ok := se.Map["name"]
+		if !ok {
+			continue
+		}
+
+		c.collectMetricsForInterface(name, se, ctx)
+	}
+
+	return nil
+}
+
+func (c *poeCollector) collectMetricsForInterface(name string, se *proto.Sentence, ctx *collectorContext) {
+	for _, prop := range c.props {
+		v, ok := se.Map[prop]
+		if !ok {
+			continue
+		}
+
+		value, err := strconv.ParseFloat(v, 64)
+		if err != nil {
+			log.WithFields(log.Fields{
+				"device":    ctx.device.Name,
+				"interface": name,
+				"property":  prop,
+				"error":     err,
+			}).Error("error parsing interface poe monitor metric")
+			return
+		}
+
+		ctx.ch <- prometheus.MustNewConstMetric(c.descForKey(prop), prometheus.GaugeValue, value, ctx.device.Name, ctx.device.Address, name)
+	}
+}
+
+func (c *poeCollector) valueForKey(name, value string) (float64, error) {
+	return strconv.ParseFloat(value, 64)
+}
+
+func (c *poeCollector) descForKey(name string) *prometheus.Desc {
+	switch name {
+	case "poe-out-current":
+		return c.currentDesc
+	case "poe-out-voltage":
+		return c.voltageDesc
+	case "poe-out-power":
+		return c.powerDesc
+	}
+
+	return nil
+}

config/config.go

@@ -15,6 +15,7 @@ type Config struct {
 		DHCP    bool `yaml:"dhcp,omitempty"`
 		DHCPv6  bool `yaml:"dhcpv6,omitempty"`
 		Routes  bool `yaml:"routes,omitempty"`
+		POE     bool `yaml:"poe,omitempty"`
 		Pools   bool `yaml:"pools,omitempty"`
 		Optics  bool `yaml:"optics,omitempty"`
 		WlanSTA bool `yaml:"wlansta,omitempty"`

main.go

@@ -38,6 +38,7 @@ var (
 	withRoutes  = flag.Bool("with-routes", false, "retrieves routing table information")
 	withDHCP    = flag.Bool("with-dhcp", false, "retrieves DHCP server metrics")
 	withDHCPv6  = flag.Bool("with-dhcpv6", false, "retrieves DHCPv6 server metrics")
+	withPOE     = flag.Bool("with-poe", false, "retrieves PoE metrics")
 	withPools   = flag.Bool("with-pools", false, "retrieves IP(v6) pool metrics")
 	withOptics  = flag.Bool("with-optics", false, "retrieves optical diagnostic metrics")
 	withWlanSTA = flag.Bool("with-wlansta", false, "retrieves connected wlan station metrics")
@@ -188,6 +189,10 @@ func collectorOptions() []collector.Option {
 		opts = append(opts, collector.WithDHCPv6())
 	}
 
+	if *withPOE || cfg.Features.POE {
+		opts = append(opts, collector.WithPOE())
+	}
+
 	if *withPools || cfg.Features.Pools {
 		opts = append(opts, collector.WithPools())
 	}