os: expose Win32_ComputerSystem and Win32_PerfRawData_PerfOS_System

collector/system.go

@@ -0,0 +1,125 @@
+// returns data points from Win32_PerfRawData_PerfOS_System class (undocumented)
+
+package collector
+
+import (
+	"log"
+
+	"github.com/StackExchange/wmi"
+	"github.com/prometheus/client_golang/prometheus"
+)
+
+func init() {
+	Factories["perfos"] = NewSystemCollector
+}
+
+// A PerfOSCollector is a Prometheus collector for WMI metrics
+type SystemCollector struct {
+	ContextSwitchesTotal     *prometheus.Desc
+	ExceptionDispatchesTotal *prometheus.Desc
+	ProcessorQueueLength     *prometheus.Desc
+	SystemCallsTotal         *prometheus.Desc
+	SystemUpTime             *prometheus.Desc
+	Threads                  *prometheus.Desc
+}
+
+// NewSystemCollector ...
+func NewSystemCollector() (Collector, error) {
+	const subsystem = "system"
+
+	return &SystemCollector{
+		ContextSwitchesTotal: prometheus.NewDesc(
+			prometheus.BuildFQName(Namespace, subsystem, "context_switches_total"),
+			"PerfOS_System.ContextSwitchesPersec",
+			nil,
+			nil,
+		),
+		ExceptionDispatchesTotal: prometheus.NewDesc(
+			prometheus.BuildFQName(Namespace, subsystem, "exception_dispatches_total"),
+			"PerfOS_System.ExceptionDispatchesPersec",
+			nil,
+			nil,
+		),
+		ProcessorQueueLength: prometheus.NewDesc(
+			prometheus.BuildFQName(Namespace, subsystem, "processor_queue_length"),
+			"PerfOS_System.ProcessorQueueLength",
+			nil,
+			nil,
+		),
+		SystemCallsTotal: prometheus.NewDesc(
+			prometheus.BuildFQName(Namespace, subsystem, "system_calls_total"),
+			"PerfOS_System.SystemCallsPersec",
+			nil,
+			nil,
+		),
+		SystemUpTime: prometheus.NewDesc(
+			prometheus.BuildFQName(Namespace, subsystem, "system_up_time"),
+			"PerfOS_System.SystemUpTime",
+			nil,
+			nil,
+		),
+		Threads: prometheus.NewDesc(
+			prometheus.BuildFQName(Namespace, subsystem, "threads"),
+			"PerfOS_System.Threads",
+			nil,
+			nil,
+		),
+	}, nil
+}
+
+// Collect sends the metric values for each metric
+// to the provided prometheus Metric channel.
+func (c *SystemCollector) Collect(ch chan<- prometheus.Metric) error {
+	if desc, err := c.collect(ch); err != nil {
+		log.Println("[ERROR] failed collecting os metrics:", desc, err)
+		return err
+	}
+	return nil
+}
+
+type Win32_PerfRawData_PerfOS_System struct {
+	ContextSwitchesPersec     uint32
+	ExceptionDispatchesPersec uint32
+	ProcessorQueueLength      uint32
+	SystemCallsPersec         uint32
+	SystemUpTime              uint64
+	Threads                   uint32
+}
+
+func (c *SystemCollector) collect(ch chan<- prometheus.Metric) (*prometheus.Desc, error) {
+	var dst []Win32_PerfRawData_PerfOS_System
+	if err := wmi.Query(wmi.CreateQuery(&dst, ""), &dst); err != nil {
+		return nil, err
+	}
+	ch <- prometheus.MustNewConstMetric(
+		c.ContextSwitchesTotal,
+		prometheus.GaugeValue,
+		float64(dst[0].ContextSwitchesPersec),
+	)
+	ch <- prometheus.MustNewConstMetric(
+		c.ExceptionDispatchesTotal,
+		prometheus.GaugeValue,
+		float64(dst[0].ExceptionDispatchesPersec),
+	)
+	ch <- prometheus.MustNewConstMetric(
+		c.ProcessorQueueLength,
+		prometheus.GaugeValue,
+		float64(dst[0].ProcessorQueueLength),
+	)
+	ch <- prometheus.MustNewConstMetric(
+		c.SystemCallsTotal,
+		prometheus.GaugeValue,
+		float64(dst[0].SystemCallsPersec),
+	)
+	ch <- prometheus.MustNewConstMetric(
+		c.SystemUpTime,
+		prometheus.GaugeValue,
+		float64(dst[0].SystemUpTime),
+	)
+	ch <- prometheus.MustNewConstMetric(
+		c.Threads,
+		prometheus.GaugeValue,
+		float64(dst[0].Threads),
+	)
+	return nil, nil
+}