Add a dogstatsd metric emitter

metric/emitter/dogstatsd.go

@@ -0,0 +1,89 @@
+package emitter
+
+import (
+	"fmt"
+	"log"
+	"regexp"
+	"strings"
+
+	"code.cloudfoundry.org/lager"
+	"github.com/DataDog/datadog-go/statsd"
+	"github.com/concourse/atc/metric"
+)
+
+type DogstatsdEmitter struct {
+	client *statsd.Client
+}
+
+type DogstatsDBConfig struct {
+	Host   string `long:"datadog-agent-host" description:"Datadog agent host"`
+	Port   string `long:"datadog-agent-port" description:"Datadog agent port"`
+	Prefix string `long:"datadog-prefix" description:"Datadog agent address to ship metrics to."`
+}
+
+func init() {
+	metric.RegisterEmitter(&DogstatsDBConfig{})
+}
+
+func (config *DogstatsDBConfig) Description() string { return "Datadog" }
+
+func (config *DogstatsDBConfig) IsConfigured() bool { return config.Host != "" && config.Port != "" }
+
+func (config *DogstatsDBConfig) NewEmitter() (metric.Emitter, error) {
+
+	client, err := statsd.New(fmt.Sprintf("%s:%s", config.Host, config.Port))
+	if err != nil {
+		log.Fatal(err)
+		return &DogstatsdEmitter{}, err
+	}
+
+	if config.Prefix != "" {
+		if strings.HasSuffix(config.Prefix, ".") {
+			client.Namespace = config.Prefix
+		} else {
+			client.Namespace = fmt.Sprintf("%s.", config.Prefix)
+		}
+	}
+
+	return &DogstatsdEmitter{
+		client: client,
+	}, nil
+}
+
+func (emitter *DogstatsdEmitter) Emit(logger lager.Logger, event metric.Event) {
+
+	reg, _ := regexp.Compile("[^a-zA-Z0-9_]+")
+
+	name := reg.ReplaceAllString(strings.Replace(strings.ToLower(event.Name), " ", "_", -1), "")
+
+	tags := []string{
+		fmt.Sprintf("host:%s", event.Host),
+		fmt.Sprintf("state:%s", event.State),
+	}
+
+	for k, v := range event.Attributes {
+		tags = append(tags, fmt.Sprintf("%s:%s", k, v))
+	}
+
+	var value float64
+
+	if i, ok := event.Value.(int); ok {
+		value = float64(i)
+	} else if f, ok := event.Value.(float64); ok {
+		value = f
+	} else {
+		logger.Error(fmt.Sprintf("failed-to-convert-metric-for-dogstatsd: %s", name), nil)
+		return
+	}
+
+	err := emitter.client.Gauge(
+		name,
+		value,
+		tags,
+		1,
+	)
+	if err != nil {
+		logger.Error("failed-to-send-metric", err)
+		return
+	}
+}