Move exporter to main and listen/interval to flags

collector/gmond_collector.go

@@ -0,0 +1,111 @@
+// +build ganglia
+
+package collector
+
+import (
+	"bufio"
+	"encoding/xml"
+	"fmt"
+	"io"
+	"net"
+	"regexp"
+	"time"
+
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/node_exporter/collector/ganglia"
+)
+
+const (
+	gangliaAddress = "127.0.0.1:8649"
+	gangliaProto   = "tcp"
+	gangliaTimeout = 30 * time.Second
+)
+
+type gmondCollector struct {
+	name     string
+	Metrics  map[string]prometheus.Gauge
+	config   Config
+	registry prometheus.Registry
+}
+
+func init() {
+	Factories = append(Factories, NewGmondCollector)
+}
+
+var illegalCharsRE = regexp.MustCompile(`[^a-zA-Z0-9_]`)
+
+// Takes a config struct and prometheus registry and returns a new Collector scraping ganglia.
+func NewGmondCollector(config Config, registry prometheus.Registry) (Collector, error) {
+	c := gmondCollector{
+		name:     "gmond_collector",
+		config:   config,
+		Metrics:  make(map[string]prometheus.Gauge),
+		registry: registry,
+	}
+
+	return &c, nil
+}
+
+func (c *gmondCollector) Name() string { return c.name }
+
+func (c *gmondCollector) setMetric(name string, labels map[string]string, metric ganglia.Metric) {
+	if _, ok := c.Metrics[name]; !ok {
+		var desc string
+		var title string
+		for _, element := range metric.ExtraData.ExtraElements {
+			switch element.Name {
+			case "DESC":
+				desc = element.Val
+			case "TITLE":
+				title = element.Val
+			}
+			if title != "" && desc != "" {
+				break
+			}
+		}
+		debug(c.Name(), "Register %s: %s", name, desc)
+		gauge := prometheus.NewGauge()
+		c.Metrics[name] = gauge
+		c.registry.Register(name, desc, prometheus.NilLabels, gauge) // one gauge per metric!
+	}
+	debug(c.Name(), "Set %s{%s}: %f", name, labels, metric.Value)
+	c.Metrics[name].Set(labels, metric.Value)
+}
+
+func (c *gmondCollector) Update() (updates int, err error) {
+	conn, err := net.Dial(gangliaProto, gangliaAddress)
+	debug(c.Name(), "gmondCollector Update")
+	if err != nil {
+		return updates, fmt.Errorf("Can't connect to gmond: %s", err)
+	}
+	conn.SetDeadline(time.Now().Add(gangliaTimeout))
+
+	ganglia := ganglia.Ganglia{}
+	decoder := xml.NewDecoder(bufio.NewReader(conn))
+	decoder.CharsetReader = toUtf8
+
+	err = decoder.Decode(&ganglia)
+	if err != nil {
+		return updates, fmt.Errorf("Couldn't parse xml: %s", err)
+	}
+
+	for _, cluster := range ganglia.Clusters {
+		for _, host := range cluster.Hosts {
+
+			for _, metric := range host.Metrics {
+				name := illegalCharsRE.ReplaceAllString(metric.Name, "_")
+
+				var labels = map[string]string{
+					"cluster": cluster.Name,
+				}
+				c.setMetric(name, labels, metric)
+				updates++
+			}
+		}
+	}
+	return updates, err
+}
+
+func toUtf8(charset string, input io.Reader) (io.Reader, error) {
+	return input, nil //FIXME
+}