implement systemd-resolved metrics collector

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

main.go

@@ -21,6 +21,7 @@ import (
 	"github.com/alecthomas/kingpin/v2"
 	"github.com/go-kit/log/level"
 	"github.com/prometheus-community/systemd_exporter/systemd"
+	"github.com/prometheus-community/systemd_exporter/systemd/resolved"
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/client_golang/prometheus/promhttp"
 	"github.com/prometheus/common/promlog"
@@ -44,6 +45,8 @@ func main() {
 			"web.max-requests",
 			"Maximum number of parallel scrape requests. Use 0 to disable.",
 		).Default("40").Int()
+		enableResolvedgMetrics = kingpin.Flag("systemd.collector.enable-resolved", "Enable systemd-resolved statistics").Bool()
+
 		toolkitFlags = webflag.AddFlags(kingpin.CommandLine, ":9558")
 	)
 
@@ -86,6 +89,18 @@ func main() {
 			exporterMetricsRegistry, handler,
 		)
 	}
+	if *enableResolvedgMetrics {
+		resolvedCollector, err := resolved.NewCollector(logger)
+		if err != nil {
+			level.Error(logger).Log("msg", "Couldn't create resolved collector", "err", err)
+			os.Exit(1)
+		}
+
+		if err := r.Register(resolvedCollector); err != nil {
+			level.Error(logger).Log("msg", "Couldn't register resolved collector", "err", err)
+			os.Exit(1)
+		}
+	}
 
 	http.Handle(*metricsPath, handler)
 	if *metricsPath != "/" && *metricsPath != "" {

systemd/resolved/resolved.go

@@ -0,0 +1,172 @@
+// Copyright 2023 The Prometheus Authors
+// 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.
+
+package resolved
+
+import (
+	"context"
+
+	"github.com/go-kit/log"
+	"github.com/go-kit/log/level"
+	"github.com/godbus/dbus/v5"
+	"github.com/prometheus/client_golang/prometheus"
+)
+
+const (
+	namespace = "systemd"
+	subsystem = "resolved"
+)
+
+type Collector struct {
+	ctx    context.Context
+	logger log.Logger
+}
+
+var (
+	resolvedCurrentTransactions = prometheus.NewDesc(
+		prometheus.BuildFQName(namespace, subsystem, "current_transactions"),
+		"Resolved Current Transactions",
+		nil, nil,
+	)
+	resolvedTotalTransactions = prometheus.NewDesc(
+		prometheus.BuildFQName(namespace, subsystem, "transactions_total"),
+		"Resolved Total Transactions",
+		nil, nil,
+	)
+	resolvedCurrentCacheSize = prometheus.NewDesc(
+		prometheus.BuildFQName(namespace, subsystem, "current_cache_size"),
+		"Resolved Current Cache Size",
+		nil, nil,
+	)
+	resolvedTotalCacheHits = prometheus.NewDesc(
+		prometheus.BuildFQName(namespace, subsystem, "cache_hits_total"),
+		"Resolved Total Cache Hits",
+		nil, nil,
+	)
+	resolvedTotalCacheMisses = prometheus.NewDesc(
+		prometheus.BuildFQName(namespace, subsystem, "cache_misses_total"),
+		"Resolved Total Cache Misses",
+		nil, nil,
+	)
+	resolvedTotalSecure = prometheus.NewDesc(
+		prometheus.BuildFQName(namespace, subsystem, "dnssec_secure_total"),
+		"Resolved Total number of DNSSEC Verdicts Secure",
+		nil, nil,
+	)
+	resolvedTotalInsecure = prometheus.NewDesc(
+		prometheus.BuildFQName(namespace, subsystem, "dnssec_insecure_total"),
+		"Resolved Total number of DNSSEC Verdicts Insecure",
+		nil, nil,
+	)
+	resolvedTotalBogus = prometheus.NewDesc(
+		prometheus.BuildFQName(namespace, subsystem, "dnssec_bogus_total"),
+		"Resolved Total number of DNSSEC Verdicts Boguss",
+		nil, nil,
+	)
+	resolvedTotalIndeterminate = prometheus.NewDesc(
+		prometheus.BuildFQName(namespace, subsystem, "dnssec_indeterminate_total"),
+		"Resolved Total number of DNSSEC Verdicts Indeterminat",
+		nil, nil,
+	)
+)
+
+// NewCollector returns a new Collector exporing resolved statistics
+func NewCollector(logger log.Logger) (*Collector, error) {
+
+	ctx := context.TODO()
+	return &Collector{
+		ctx:    ctx,
+		logger: logger,
+	}, nil
+}
+
+// Collect gathers metrics from resolved
+func (c *Collector) Collect(ch chan<- prometheus.Metric) {
+	err := c.collect(ch)
+	if err != nil {
+		level.Error(c.logger).Log("msg", "error collecting resolved metrics",
+			"err", err)
+	}
+}
+
+// Describe gathers descriptions of metrics
+func (c *Collector) Describe(desc chan<- *prometheus.Desc) {
+	desc <- resolvedCurrentTransactions
+	desc <- resolvedTotalTransactions
+	desc <- resolvedCurrentCacheSize
+	desc <- resolvedTotalCacheHits
+	desc <- resolvedTotalCacheMisses
+	desc <- resolvedTotalSecure
+	desc <- resolvedTotalInsecure
+	desc <- resolvedTotalBogus
+	desc <- resolvedTotalIndeterminate
+}
+
+func parseProperty(object dbus.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 {
+
+	conn, err := dbus.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(resolvedCurrentCacheSize, prometheus.GaugeValue,
+		float64(cacheStats[0]))
+	ch <- prometheus.MustNewConstMetric(resolvedTotalCacheHits, prometheus.CounterValue,
+		float64(cacheStats[1]))
+	ch <- prometheus.MustNewConstMetric(resolvedTotalCacheMisses, prometheus.CounterValue,
+		float64(cacheStats[2]))
+
+	transactionStats, err := parseProperty(obj, "org.freedesktop.resolve1.Manager.TransactionStatistics")
+	ch <- prometheus.MustNewConstMetric(resolvedCurrentTransactions, prometheus.GaugeValue,
+		float64(transactionStats[0]))
+	ch <- prometheus.MustNewConstMetric(resolvedTotalTransactions, prometheus.CounterValue,
+		float64(transactionStats[1]))
+	if err != nil {
+		return err
+	}
+
+	dnssecStats, err := parseProperty(obj, "org.freedesktop.resolve1.Manager.DNSSECStatistics")
+	ch <- prometheus.MustNewConstMetric(resolvedTotalSecure, prometheus.CounterValue,
+		float64(dnssecStats[0]))
+	ch <- prometheus.MustNewConstMetric(resolvedTotalInsecure, prometheus.CounterValue,
+		float64(dnssecStats[1]))
+	ch <- prometheus.MustNewConstMetric(resolvedTotalBogus, prometheus.CounterValue,
+		float64(dnssecStats[2]))
+	ch <- prometheus.MustNewConstMetric(resolvedTotalIndeterminate, prometheus.CounterValue,
+		float64(dnssecStats[3]))
+	if err != nil {
+		return err
+	}
+	return nil
+}