Add connection tracking collector

collector/collector.go

@@ -175,6 +175,13 @@ func WithIpsec() Option {
 	}
 }
 
+// WithConntrack enables firewall/NAT connection tracking metrics
+func WithConntrack() Option {
+	return func(c *collector) {
+		c.collectors = append(c.collectors, newConntrackCollector())
+	}
+}
+
 // Option applies options to collector
 type Option func(*collector)
 

collector/conntrack_collector.go

@@ -0,0 +1,68 @@
+package collector
+
+import (
+	"strconv"
+	"strings"
+
+	"github.com/prometheus/client_golang/prometheus"
+	log "github.com/sirupsen/logrus"
+	"gopkg.in/routeros.v2/proto"
+)
+
+type conntrackCollector struct {
+	props            []string
+	totalEntriesDesc *prometheus.Desc
+	maxEntriesDesc   *prometheus.Desc
+}
+
+func newConntrackCollector() routerOSCollector {
+	const prefix = "conntrack"
+
+	labelNames := []string{"name", "address"}
+	return &conntrackCollector{
+		props:            []string{"total-entries", "max-entries"},
+		totalEntriesDesc: description(prefix, "entries", "Number of tracked connections", labelNames),
+		maxEntriesDesc:   description(prefix, "max_entries", "Conntrack table capacity", labelNames),
+	}
+}
+
+func (c *conntrackCollector) describe(ch chan<- *prometheus.Desc) {
+	ch <- c.totalEntriesDesc
+	ch <- c.maxEntriesDesc
+}
+
+func (c *conntrackCollector) collect(ctx *collectorContext) error {
+	reply, err := ctx.client.Run("/ip/firewall/connection/tracking/print", "=.proplist="+strings.Join(c.props, ","))
+	if err != nil {
+		log.WithFields(log.Fields{
+			"device": ctx.device.Name,
+			"error":  err,
+		}).Error("error fetching conntrack table metrics")
+		return err
+	}
+
+	for _, re := range reply.Re {
+		c.collectMetricForProperty("total-entries", c.totalEntriesDesc, re, ctx)
+		c.collectMetricForProperty("max-entries", c.maxEntriesDesc, re, ctx)
+	}
+
+	return nil
+}
+
+func (c *conntrackCollector) collectMetricForProperty(property string, desc *prometheus.Desc, re *proto.Sentence, ctx *collectorContext) {
+	if re.Map[property] == "" {
+		return
+	}
+	v, err := strconv.ParseFloat(re.Map[property], 64)
+	if err != nil {
+		log.WithFields(log.Fields{
+			"device":   ctx.device.Name,
+			"property": property,
+			"value":    re.Map[property],
+			"error":    err,
+		}).Error("error parsing conntrack metric value")
+		return
+	}
+
+	ctx.ch <- prometheus.MustNewConstMetric(desc, prometheus.GaugeValue, v, ctx.device.Name, ctx.device.Address)
+}

config/config.go

@@ -12,6 +12,7 @@ type Config struct {
 	Devices  []Device `yaml:"devices"`
 	Features struct {
 		BGP       bool `yaml:"bgp,omitempty"`
+		Conntrack bool `yaml:"conntrack,omitempty"`
 		DHCP      bool `yaml:"dhcp,omitempty"`
 		DHCPL     bool `yaml:"dhcpl,omitempty"`
 		DHCPv6    bool `yaml:"dhcpv6,omitempty"`

config/config.test.yml

@@ -10,6 +10,7 @@ devices:
 
 features:
   bgp: true
+  conntrack: true
   dhcp: true
   dhcpv6: true
   dhcpl: true

config/config_test.go

@@ -20,6 +20,7 @@ func TestShouldParse(t *testing.T) {
 	assertDevice("test1", "192.168.1.1", "foo", "bar", c.Devices[0], t)
 	assertDevice("test2", "192.168.2.1", "test", "123", c.Devices[1], t)
 	assertFeature("BGP", c.Features.BGP, t)
+	assertFeature("Conntrack", c.Features.Conntrack, t)
 	assertFeature("DHCP", c.Features.DHCP, t)
 	assertFeature("DHCPv6", c.Features.DHCPv6, t)
 	assertFeature("Pools", c.Features.Pools, t)

main.go

@@ -37,6 +37,7 @@ var (
 	ver         = flag.Bool("version", false, "find the version of binary")
 
 	withBgp       = flag.Bool("with-bgp", false, "retrieves BGP routing infrormation")
+	withConntrack = flag.Bool("with-conntrack", false, "retrieves connection tracking metrics")
 	withRoutes    = flag.Bool("with-routes", false, "retrieves routing table information")
 	withDHCP      = flag.Bool("with-dhcp", false, "retrieves DHCP server metrics")
 	withDHCPL     = flag.Bool("with-dhcpl", false, "retrieves DHCP server lease metrics")
@@ -241,6 +242,10 @@ func collectorOptions() []collector.Option {
 		opts = append(opts, collector.WithIpsec())
 	}
 
+	if *withConntrack || cfg.Features.Conntrack {
+		opts = append(opts, collector.WithConntrack())
+	}
+
 	if *timeout != collector.DefaultTimeout {
 		opts = append(opts, collector.WithTimeout(*timeout))
 	}