collector: support 1,5,15m load averages for all unices

collector/loadavg.go

@@ -12,59 +12,56 @@
 // limitations under the License.
 
 // +build !noloadavg
-// +build !linux
 
 package collector
 
 import (
-	"errors"
 	"fmt"
 
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/common/log"
 )
 
-// #include <stdlib.h>
-import "C"
-
 type loadavgCollector struct {
-	metric prometheus.Gauge
+	metric []prometheus.Gauge
 }
 
 func init() {
 	Factories["loadavg"] = NewLoadavgCollector
 }
 
-// Takes a prometheus registry and returns a new Collector exposing
-// load1 stat.
+// Take a prometheus registry and return a new Collector exposing load average.
 func NewLoadavgCollector() (Collector, error) {
 	return &loadavgCollector{
-		metric: prometheus.NewGauge(prometheus.GaugeOpts{
-			Namespace: Namespace,
-			Name:      "load1",
-			Help:      "1m load average.",
-		}),
+		metric: []prometheus.Gauge{
+			prometheus.NewGauge(prometheus.GaugeOpts{
+				Namespace: Namespace,
+				Name:      "load1",
+				Help:      "1m load average.",
+			}),
+			prometheus.NewGauge(prometheus.GaugeOpts{
+				Namespace: Namespace,
+				Name:      "load5",
+				Help:      "5m load average.",
+			}),
+			prometheus.NewGauge(prometheus.GaugeOpts{
+				Namespace: Namespace,
+				Name:      "load15",
+				Help:      "15m load average.",
+			}),
+		},
 	}, nil
 }
 
 func (c *loadavgCollector) Update(ch chan<- prometheus.Metric) (err error) {
-	load, err := getLoad1()
+	loads, err := getLoad()
 	if err != nil {
 		return fmt.Errorf("couldn't get load: %s", err)
 	}
-	log.Debugf("Set node_load: %f", load)
-	c.metric.Set(load)
-	c.metric.Collect(ch)
+	for i, load := range loads {
+		log.Debugf("Set load %d: %f", i, load)
+		c.metric[i].Set(load)
+		c.metric[i].Collect(ch)
+	}
 	return err
 }
-
-func getLoad1() (float64, error) {
-	var loadavg [1]C.double
-	samples := C.getloadavg(&loadavg[0], 1)
-	if samples > 0 {
-		return float64(loadavg[0]), nil
-	} else {
-		return 0, errors.New("failed to get load average")
-	}
-
-}