implement systemd-resolved metrics collector

 - collect systemd-resolved metrics through dbus
 - add new option to enable collector
 - fix #37

Signed-off-by: egmc <[email protected]>

Author: egmc

go.mod

@@ -6,6 +6,7 @@ require (
 	github.com/alecthomas/kingpin/v2 v2.3.2
 	github.com/coreos/go-systemd/v22 v22.5.0
 	github.com/go-kit/log v0.2.1
+	github.com/godbus/dbus/v5 v5.0.4
 	github.com/pkg/errors v0.9.1
 	github.com/prometheus/client_golang v1.17.0
 	github.com/prometheus/common v0.45.0
@@ -17,7 +18,6 @@ require (
 	github.com/beorn7/perks v1.0.1 // indirect
 	github.com/cespare/xxhash/v2 v2.2.0 // indirect
 	github.com/go-logfmt/logfmt v0.5.1 // indirect
-	github.com/godbus/dbus/v5 v5.0.4 // indirect
 	github.com/golang/protobuf v1.5.3 // indirect
 	github.com/jpillora/backoff v1.0.0 // indirect
 	github.com/kr/text v0.2.0 // indirect

systemd/systemd.go

@@ -31,6 +31,8 @@ import (
 	"github.com/go-kit/log/level"
 	"github.com/pkg/errors"
 	"github.com/prometheus/client_golang/prometheus"
+
+	godbus "github.com/godbus/dbus/v5"
 )
 
 const namespace = "systemd"
@@ -42,6 +44,7 @@ var (
 	systemdUser               = kingpin.Flag("systemd.collector.user", "Connect to the user systemd instance.").Bool()
 	enableRestartsMetrics     = kingpin.Flag("systemd.collector.enable-restart-count", "Enables service restart count metrics. This feature only works with systemd 235 and above.").Bool()
 	enableIPAccountingMetrics = kingpin.Flag("systemd.collector.enable-ip-accounting", "Enables service ip accounting metrics. This feature only works with systemd 235 and above.").Bool()
+	enableResolvedgMetrics    = kingpin.Flag("systemd.collector.enable-resolved", "Enable systemd-resolved statistics").Bool()
 )
 
 var unitStatesName = []string{"active", "activating", "deactivating", "inactive", "failed"}
@@ -80,6 +83,16 @@ type Collector struct {
 
 	unitIncludePattern *regexp.Regexp
 	unitExcludePattern *regexp.Regexp
+
+	resolvedCurrentTransactions *prometheus.Desc
+	resolvedTotalTransactions   *prometheus.Desc
+	resolvedCurrentCacheSize    *prometheus.Desc
+	resolvedTotalCacheHits      *prometheus.Desc
+	resolvedTotalCacheMisses    *prometheus.Desc
+	resolvedTotalSecure         *prometheus.Desc
+	resolvedTotalInsecure       *prometheus.Desc
+	resolvedTotalBogus          *prometheus.Desc
+	resolvedTotalIndeterminate  *prometheus.Desc
 }
 
 // NewCollector returns a new Collector exposing systemd statistics.
@@ -189,6 +202,53 @@ func NewCollector(logger log.Logger) (*Collector, error) {
 	unitIncludePattern := regexp.MustCompile(fmt.Sprintf("^(?:%s)$", *unitInclude))
 	unitExcludePattern := regexp.MustCompile(fmt.Sprintf("^(?:%s)$", *unitExclude))
 
+	// resolved metrics
+	resolvedCurrentTransactions := prometheus.NewDesc(
+		prometheus.BuildFQName(namespace, "", "resolved_current_transactions"),
+		"Resolved Current Transactions",
+		nil, nil,
+	)
+	resolvedTotalTransactions := prometheus.NewDesc(
+		prometheus.BuildFQName(namespace, "", "resolved_transactions_total"),
+		"Resolved Total Transactions",
+		nil, nil,
+	)
+	resolvedCurrentCacheSize := prometheus.NewDesc(
+		prometheus.BuildFQName(namespace, "", "resolved_current_cache_size"),
+		"Resolved Current Cache Size",
+		nil, nil,
+	)
+	resolvedTotalCacheHits := prometheus.NewDesc(
+		prometheus.BuildFQName(namespace, "", "resolved_cache_hits_total"),
+		"Resolved Total Cache Hits",
+		nil, nil,
+	)
+	resolvedTotalCacheMisses := prometheus.NewDesc(
+		prometheus.BuildFQName(namespace, "", "resolved_cache_misses_total"),
+		"Resolved Total Cache Misses",
+		nil, nil,
+	)
+	resolvedTotalSecure := prometheus.NewDesc(
+		prometheus.BuildFQName(namespace, "", "resolved_dnssec_secure_total"),
+		"Resolved Total number of DNSSEC Verdicts Secure",
+		nil, nil,
+	)
+	resolvedTotalInsecure := prometheus.NewDesc(
+		prometheus.BuildFQName(namespace, "", "resolved_dnssec_insecure_total"),
+		"Resolved Total number of DNSSEC Verdicts Insecure",
+		nil, nil,
+	)
+	resolvedTotalBogus := prometheus.NewDesc(
+		prometheus.BuildFQName(namespace, "", "resolved_dnssec_bogus_total"),
+		"Resolved Total number of DNSSEC Verdicts Boguss",
+		nil, nil,
+	)
+	resolvedTotalIndeterminate := prometheus.NewDesc(
+		prometheus.BuildFQName(namespace, "", "resolved_dnssec_indeterminate_total"),
+		"Resolved Total number of DNSSEC Verdicts Indeterminat",
+		nil, nil,
+	)
+
 	// TODO: Build a custom handler to pass in the scrape http context.
 	ctx := context.TODO()
 	return &Collector{
@@ -215,6 +275,16 @@ func NewCollector(logger log.Logger) (*Collector, error) {
 		ipEgressPackets:               ipEgressPackets,
 		unitIncludePattern:            unitIncludePattern,
 		unitExcludePattern:            unitExcludePattern,
+
+		resolvedCurrentTransactions: resolvedCurrentTransactions,
+		resolvedTotalTransactions:   resolvedTotalTransactions,
+		resolvedCurrentCacheSize:    resolvedCurrentCacheSize,
+		resolvedTotalCacheHits:      resolvedTotalCacheHits,
+		resolvedTotalCacheMisses:    resolvedTotalCacheMisses,
+		resolvedTotalSecure:         resolvedTotalSecure,
+		resolvedTotalInsecure:       resolvedTotalInsecure,
+		resolvedTotalBogus:          resolvedTotalBogus,
+		resolvedTotalIndeterminate:  resolvedTotalIndeterminate,
 	}, nil
 }
 
@@ -243,6 +313,15 @@ func (c *Collector) Describe(desc chan<- *prometheus.Desc) {
 	desc <- c.ipEgressBytes
 	desc <- c.ipIngressPackets
 	desc <- c.ipEgressPackets
+	desc <- c.resolvedCurrentTransactions
+	desc <- c.resolvedTotalTransactions
+	desc <- c.resolvedCurrentCacheSize
+	desc <- c.resolvedTotalCacheHits
+	desc <- c.resolvedTotalCacheMisses
+	desc <- c.resolvedTotalSecure
+	desc <- c.resolvedTotalInsecure
+	desc <- c.resolvedTotalBogus
+	desc <- c.resolvedTotalIndeterminate
 
 }
 
@@ -251,6 +330,18 @@ func parseUnitType(unit dbus.UnitStatus) string {
 	return t[len(t)-1]
 }
 
+func parseProperty(object godbus.BusObject, path string) (ret []float64, err error) {
+	variant, err := object.GetProperty(path)
+	if err != nil {
+		return nil, err
+	}
+	for _, v := range variant.Value().([]interface{}) {
+		i := v.(uint64)
+		ret = append(ret, float64(i))
+	}
+	return ret, err
+}
+
 func (c *Collector) collect(ch chan<- prometheus.Metric) error {
 	begin := time.Now()
 	conn, err := c.newDbus()
@@ -282,6 +373,14 @@ func (c *Collector) collect(ch chan<- prometheus.Metric) error {
 	}
 
 	wg.Wait()
+
+	if *enableResolvedgMetrics {
+		err := c.collectResolvedMetrics(ch)
+		if err != nil {
+			level.Warn(c.logger).Log("msg", "couldn't get resolved metrics", "err", err)
+		}
+	}
+
 	return nil
 }
 
@@ -594,6 +693,53 @@ func (c *Collector) collectTimerTriggerTime(conn *dbus.Conn, ch chan<- prometheu
 	return nil
 }
 
+func (c *Collector) collectResolvedMetrics(ch chan<- prometheus.Metric) error {
+
+	conn, err := godbus.ConnectSystemBus()
+	if err != nil {
+		return err
+	}
+
+	defer conn.Close()
+
+	obj := conn.Object("org.freedesktop.resolve1", "/org/freedesktop/resolve1")
+
+	cacheStats, err := parseProperty(obj, "org.freedesktop.resolve1.Manager.CacheStatistics")
+	if err != nil {
+		return err
+	}
+
+	ch <- prometheus.MustNewConstMetric(c.resolvedCurrentCacheSize, prometheus.GaugeValue,
+		float64(cacheStats[0]))
+	ch <- prometheus.MustNewConstMetric(c.resolvedTotalCacheHits, prometheus.CounterValue,
+		float64(cacheStats[1]))
+	ch <- prometheus.MustNewConstMetric(c.resolvedTotalCacheMisses, prometheus.CounterValue,
+		float64(cacheStats[2]))
+
+	transactionStats, err := parseProperty(obj, "org.freedesktop.resolve1.Manager.TransactionStatistics")
+	ch <- prometheus.MustNewConstMetric(c.resolvedCurrentTransactions, prometheus.GaugeValue,
+		float64(transactionStats[0]))
+	ch <- prometheus.MustNewConstMetric(c.resolvedTotalTransactions, prometheus.CounterValue,
+		float64(transactionStats[1]))
+	if err != nil {
+		return err
+	}
+
+	dnssecStats, err := parseProperty(obj, "org.freedesktop.resolve1.Manager.DNSSECStatistics")
+	ch <- prometheus.MustNewConstMetric(c.resolvedTotalSecure, prometheus.CounterValue,
+		float64(dnssecStats[0]))
+	ch <- prometheus.MustNewConstMetric(c.resolvedTotalInsecure, prometheus.CounterValue,
+		float64(dnssecStats[1]))
+	ch <- prometheus.MustNewConstMetric(c.resolvedTotalBogus, prometheus.CounterValue,
+		float64(dnssecStats[2]))
+	ch <- prometheus.MustNewConstMetric(c.resolvedTotalIndeterminate, prometheus.CounterValue,
+		float64(dnssecStats[3]))
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
 func (c *Collector) newDbus() (*dbus.Conn, error) {
 	if *systemdPrivate {
 		return dbus.NewSystemdConnectionContext(c.ctx)