Add cpu collector for FreeBSD.

collector/cpu_freebsd.go

@@ -0,0 +1,71 @@
+// +build freebsd,!nostat
+
+package collector
+
+import (
+	"errors"
+	"strconv"
+	"unsafe"
+
+	"github.com/prometheus/client_golang/prometheus"
+)
+
+/*
+#cgo LDFLAGS: -lkvm
+#include <fcntl.h>
+#include <kvm.h>
+#include <sys/param.h>
+#include <sys/pcpu.h>
+#include <sys/resource.h>
+*/
+import "C"
+
+const ()
+
+type statCollector struct {
+	config Config
+	cpu    *prometheus.CounterVec
+}
+
+func init() {
+	Factories["cpu"] = NewStatCollector
+}
+
+// Takes a config struct and prometheus registry and returns a new Collector exposing
+// network device stats.
+func NewStatCollector(config Config) (Collector, error) {
+	return &statCollector{
+		config: config,
+		cpu: prometheus.NewCounterVec(
+			prometheus.CounterOpts{
+				Namespace: Namespace,
+				Name:      "cpu",
+				Help:      "Seconds the cpus spent in each mode.",
+			},
+			[]string{"cpu", "mode"},
+		),
+	}, nil
+}
+
+// Expose cpu stats using kvm
+func (c *statCollector) Update(ch chan<- prometheus.Metric) (err error) {
+	var errbuf *C.char
+	kd := C.kvm_open(nil, nil, nil, C.O_RDONLY, errbuf)
+	if errbuf != nil {
+		return errors.New("Failed to call kvm_open().")
+	}
+	defer C.kvm_close(kd)
+
+	ncpus := C.kvm_getncpus(kd)
+	for i := 0; i < int(ncpus); i++ {
+		pcpu := C.kvm_getpcpu(kd, C.int(i))
+		cp_time := ((*C.struct_pcpu)(unsafe.Pointer(pcpu))).pc_cp_time
+		c.cpu.With(prometheus.Labels{"cpu": strconv.Itoa(i), "mode": "user"}).Set(float64(cp_time[C.CP_USER]))
+		c.cpu.With(prometheus.Labels{"cpu": strconv.Itoa(i), "mode": "nice"}).Set(float64(cp_time[C.CP_NICE]))
+		c.cpu.With(prometheus.Labels{"cpu": strconv.Itoa(i), "mode": "system"}).Set(float64(cp_time[C.CP_SYS]))
+		c.cpu.With(prometheus.Labels{"cpu": strconv.Itoa(i), "mode": "interrupt"}).Set(float64(cp_time[C.CP_INTR]))
+		c.cpu.With(prometheus.Labels{"cpu": strconv.Itoa(i), "mode": "idle"}).Set(float64(cp_time[C.CP_IDLE]))
+	}
+	c.cpu.Collect(ch)
+	return err
+}