Add Windows Time Service collector

Signed-off-by: Ben Reedy <breed808@breed808.com>

collector/time.go

@@ -0,0 +1,124 @@
+// +build windows
+
+package collector
+
+import (
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/common/log"
+)
+
+func init() {
+	registerCollector("time", newTimeCollector, "Windows Time Service")
+}
+
+// TimeCollector is a Prometheus collector for Perflib counter metrics
+type TimeCollector struct {
+	ClockFrequencyAdjustmentPPBTotal *prometheus.Desc
+	ComputedTimeOffset               *prometheus.Desc
+	NTPClientTimeSourceCount         *prometheus.Desc
+	NTPRoundtripDelay                *prometheus.Desc
+	NTPServerIncomingRequestsTotal   *prometheus.Desc
+	NTPServerOutgoingResponsesTotal  *prometheus.Desc
+}
+
+func newTimeCollector() (Collector, error) {
+	const subsystem = "time"
+
+	return &TimeCollector{
+		ClockFrequencyAdjustmentPPBTotal: prometheus.NewDesc(
+			prometheus.BuildFQName(Namespace, subsystem, "clock_frequency_adjustment_ppb_total"),
+			"Total adjustment made to the local system clock frequency by W32Time in Parts Per Billion (PPB) units.",
+			nil,
+			nil,
+		),
+		ComputedTimeOffset: prometheus.NewDesc(
+			prometheus.BuildFQName(Namespace, subsystem, "computed_time_offset_seconds"),
+			"Absolute time offset between the system clock and the chosen time source, in seconds",
+			nil,
+			nil,
+		),
+		NTPClientTimeSourceCount: prometheus.NewDesc(
+			prometheus.BuildFQName(Namespace, subsystem, "ntp_client_time_source_count"),
+			"Active number of NTP Time sources being used by the client",
+			nil,
+			nil,
+		),
+		NTPRoundtripDelay: prometheus.NewDesc(
+			prometheus.BuildFQName(Namespace, subsystem, "ntp_round_trip_delay_seconds"),
+			"Roundtrip delay experienced by the NTP client in receiving a response from the server for the most recent request, in seconds",
+			nil,
+			nil,
+		),
+		NTPServerOutgoingResponsesTotal: prometheus.NewDesc(
+			prometheus.BuildFQName(Namespace, subsystem, "ntp_server_outgoing_responses_total"),
+			"Total number of requests responded to by NTP server",
+			nil,
+			nil,
+		),
+		NTPServerIncomingRequestsTotal: prometheus.NewDesc(
+			prometheus.BuildFQName(Namespace, subsystem, "ntp_server_incoming_requests_total"),
+			"Total number of requests received by NTP server",
+			nil,
+			nil,
+		),
+	}, nil
+}
+
+// Collect sends the metric values for each metric
+// to the provided prometheus Metric channel.
+func (c *TimeCollector) Collect(ctx *ScrapeContext, ch chan<- prometheus.Metric) error {
+	if desc, err := c.collect(ctx, ch); err != nil {
+		log.Error("failed collecting time metrics:", desc, err)
+		return err
+	}
+	return nil
+}
+
+// Perflib "Windows Time Service"
+type windowsTime struct {
+	ClockFrequencyAdjustmentPPBTotal float64 `perflib:"Clock Frequency Adjustment (ppb)"`
+	ComputedTimeOffset               float64 `perflib:"Computed Time Offset"`
+	NTPClientTimeSourceCount         float64 `perflib:"NTP Client Time Source Count"`
+	NTPRoundtripDelay                float64 `perflib:"NTP Roundtrip Delay"`
+	NTPServerIncomingRequestsTotal   float64 `perflib:"NTP Server Incoming Requests"`
+	NTPServerOutgoingResponsesTotal  float64 `perflib:"NTP Server Outgoing Responses"`
+}
+
+func (c *TimeCollector) collect(ctx *ScrapeContext, ch chan<- prometheus.Metric) (*prometheus.Desc, error) {
+	var dst []windowsTime // Single-instance class, array is required but will have single entry.
+	if err := unmarshalObject(ctx.perfObjects["Windows Time Service"], &dst); err != nil {
+		return nil, err
+	}
+
+	ch <- prometheus.MustNewConstMetric(
+		c.ClockFrequencyAdjustmentPPBTotal,
+		prometheus.CounterValue,
+		dst[0].ClockFrequencyAdjustmentPPBTotal,
+	)
+	ch <- prometheus.MustNewConstMetric(
+		c.ComputedTimeOffset,
+		prometheus.GaugeValue,
+		dst[0].ComputedTimeOffset/1000000, // microseconds -> seconds
+	)
+	ch <- prometheus.MustNewConstMetric(
+		c.NTPClientTimeSourceCount,
+		prometheus.GaugeValue,
+		dst[0].NTPClientTimeSourceCount,
+	)
+	ch <- prometheus.MustNewConstMetric(
+		c.NTPRoundtripDelay,
+		prometheus.GaugeValue,
+		dst[0].NTPRoundtripDelay/1000000, // microseconds -> seconds
+	)
+	ch <- prometheus.MustNewConstMetric(
+		c.NTPServerIncomingRequestsTotal,
+		prometheus.CounterValue,
+		dst[0].NTPServerIncomingRequestsTotal,
+	)
+	ch <- prometheus.MustNewConstMetric(
+		c.NTPServerOutgoingResponsesTotal,
+		prometheus.CounterValue,
+		dst[0].NTPServerOutgoingResponsesTotal,
+	)
+	return nil, nil
+}