Add per metric tags

.gitignore

@@ -13,3 +13,6 @@
 
 # Dependency directories
 vendor/
+
+#IntelliJ
+.idea/

go.mod

@@ -6,5 +6,5 @@ require (
 	github.com/DataDog/datadog-go v4.6.0+incompatible
 	github.com/Microsoft/go-winio v0.5.0 // indirect
 	github.com/rcrowley/go-metrics v0.0.0-20201227073835-cf1acfcdf475
-	github.com/stretchr/testify v1.7.0 // indirect
+	github.com/stretchr/testify v1.7.0
 )

go.sum

@@ -19,6 +19,7 @@ github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/
 golang.org/x/sys v0.0.0-20191026070338-33540a1f6037/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210124154548-22da62e12c0c h1:VwygUrnw9jn88c4u8GD3rZQbqrP/tgas88tPUbBxQrk=
 golang.org/x/sys v0.0.0-20210124154548-22da62e12c0c/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c h1:dUUwHk2QECo/6vqA44rthZ8ie2QXMNeKRTHCNY2nXvo=
 gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

reporter.go

@@ -3,7 +3,9 @@ package datadog
 import (
 	"fmt"
 	"log"
+	"regexp"
 	"runtime"
+	"strings"
 	"time"
 
 	"github.com/DataDog/datadog-go/statsd"
@@ -14,6 +16,10 @@ const (
 	defaultFlushInterval = time.Second * 10
 )
 
+// Expect the tags in the pattern
+// namespace.metricName[tag1:value1,tag2:value2,etc....]
+var tagPattern = regexp.MustCompile("([\\w\\.]+)\\[([\\w\\W]+)\\]")
+
 // Reporter wraps a metrics registry with a given statsd client.
 type Reporter struct {
 	// Registry matrices that need to be reported to the Client
@@ -79,61 +85,63 @@ func (r *Reporter) Flush() {
 // be used in a loop similarly to FlushWithInterval for custom error handling or
 // data submission variations.
 func (r *Reporter) FlushOnce() error {
-	r.Registry.Each(func(name string, i interface{}) {
+	r.Registry.Each(func(metricName string, i interface{}) {
+		name, tags := r.splitNameAndTags(metricName)
+
 		switch metric := i.(type) {
 		case metrics.Counter:
 			v := metric.Count()
 			l := r.ss[name]
-			r.Client.Count(name, v-l, r.tags, 1)
+			r.Client.Count(name, v-l, tags, 1)
 			r.ss[name] = v
 
 		case metrics.Gauge:
-			r.Client.Gauge(name, float64(metric.Value()), r.tags, 1)
+			r.Client.Gauge(name, float64(metric.Value()), tags, 1)
 
 		case metrics.GaugeFloat64:
-			r.Client.Gauge(name, metric.Value(), r.tags, 1)
+			r.Client.Gauge(name, metric.Value(), tags, 1)
 
 		case metrics.Histogram:
 			ms := metric.Snapshot()
 
-			r.Client.Gauge(name+".count", float64(ms.Count()), r.tags, 1)
-			r.Client.Gauge(name+".max", float64(ms.Max()), r.tags, 1)
-			r.Client.Gauge(name+".min", float64(ms.Min()), r.tags, 1)
-			r.Client.Gauge(name+".mean", ms.Mean(), r.tags, 1)
-			r.Client.Gauge(name+".stddev", ms.StdDev(), r.tags, 1)
-			r.Client.Gauge(name+".sum", float64(ms.Sum()), r.tags, 1)
-			r.Client.Gauge(name+".var", ms.Variance(), r.tags, 1)
+			r.Client.Gauge(name+".count", float64(ms.Count()), tags, 1)
+			r.Client.Gauge(name+".max", float64(ms.Max()), tags, 1)
+			r.Client.Gauge(name+".min", float64(ms.Min()), tags, 1)
+			r.Client.Gauge(name+".mean", ms.Mean(), tags, 1)
+			r.Client.Gauge(name+".stddev", ms.StdDev(), tags, 1)
+			r.Client.Gauge(name+".sum", float64(ms.Sum()), tags, 1)
+			r.Client.Gauge(name+".var", ms.Variance(), tags, 1)
 
 			if len(r.percentiles) > 0 {
 				values := ms.Percentiles(r.percentiles)
 				for i, p := range r.p {
-					r.Client.Gauge(name+p, values[i], r.tags, 1)
+					r.Client.Gauge(name+p, values[i], tags, 1)
 				}
 			}
 
 		case metrics.Meter:
 			ms := metric.Snapshot()
 
-			r.Client.Gauge(name+".count", float64(ms.Count()), r.tags, 1)
-			r.Client.Gauge(name+".rate1", ms.Rate1(), r.tags, 1)
-			r.Client.Gauge(name+".rate5", ms.Rate5(), r.tags, 1)
-			r.Client.Gauge(name+".rate15", ms.Rate15(), r.tags, 1)
-			r.Client.Gauge(name+".mean", ms.RateMean(), r.tags, 1)
+			r.Client.Gauge(name+".count", float64(ms.Count()), tags, 1)
+			r.Client.Gauge(name+".rate1", ms.Rate1(), tags, 1)
+			r.Client.Gauge(name+".rate5", ms.Rate5(), tags, 1)
+			r.Client.Gauge(name+".rate15", ms.Rate15(), tags, 1)
+			r.Client.Gauge(name+".mean", ms.RateMean(), tags, 1)
 
 		case metrics.Timer:
 			ms := metric.Snapshot()
 
-			r.Client.Gauge(name+".count", float64(ms.Count()), r.tags, 1)
-			r.Client.Gauge(name+".max", time.Duration(ms.Max()).Seconds()*1000, r.tags, 1)
-			r.Client.Gauge(name+".min", time.Duration(ms.Min()).Seconds()*1000, r.tags, 1)
-			r.Client.Gauge(name+".mean", time.Duration(ms.Mean()).Seconds()*1000, r.tags, 1)
-			r.Client.Gauge(name+".stddev", time.Duration(ms.StdDev()).Seconds()*1000, r.tags, 1)
-			r.Client.Gauge(name+".sum", float64(ms.Sum()), r.tags, 1)
+			r.Client.Gauge(name+".count", float64(ms.Count()), tags, 1)
+			r.Client.Gauge(name+".max", time.Duration(ms.Max()).Seconds()*1000, tags, 1)
+			r.Client.Gauge(name+".min", time.Duration(ms.Min()).Seconds()*1000, tags, 1)
+			r.Client.Gauge(name+".mean", time.Duration(ms.Mean()).Seconds()*1000, tags, 1)
+			r.Client.Gauge(name+".stddev", time.Duration(ms.StdDev()).Seconds()*1000, tags, 1)
+			r.Client.Gauge(name+".sum", float64(ms.Sum()), tags, 1)
 
 			if len(r.percentiles) > 0 {
 				values := ms.Percentiles(r.percentiles)
 				for i, p := range r.p {
-					r.Client.Gauge(name+p, time.Duration(values[i]).Seconds()*1000, r.tags, 1)
+					r.Client.Gauge(name+p, time.Duration(values[i]).Seconds()*1000, tags, 1)
 				}
 			}
 		}
@@ -153,3 +161,14 @@ func handlePanic(rec interface{}) {
 	}
 	log.Printf("Recovered from panic: %#v \n%v", rec, callers)
 }
+
+func (r *Reporter) splitNameAndTags(metric string) (string, []string) {
+	if res := tagPattern.FindStringSubmatch(metric); len(res) == 3 {
+		if r.tags == nil {
+			return res[1], append(strings.Split(res[2], ","))
+		} else {
+			return res[1], append(strings.Split(res[2], ","), r.tags...)
+		}
+	}
+	return metric, r.tags
+}

reporter_test.go

@@ -0,0 +1,56 @@
+package datadog
+
+import (
+	"github.com/rcrowley/go-metrics"
+	"github.com/stretchr/testify/assert"
+	"testing"
+)
+
+func TestSplitNameAndTagsNoTags(t *testing.T) {
+	reporter := &Reporter{
+		Registry: metrics.DefaultRegistry,
+	}
+
+	var metricName = "test.metric_name"
+	name, tags := reporter.splitNameAndTags(metricName)
+	assert.NotNil(t, name, "name")
+	assert.Nil(t, tags, "tags")
+
+	assert.Equal(t, "test.metric_name", name)
+}
+
+func TestSplitNameAndTagsSingleTag(t *testing.T) {
+	reporter := &Reporter{
+		Registry: metrics.DefaultRegistry,
+	}
+
+	var metricName = "test.httpcall[method:GET]"
+
+	name, tags := reporter.splitNameAndTags(metricName)
+	assert.NotNil(t, name, "name")
+	assert.NotNil(t, tags, "tags")
+	assert.Equal(t, 1, len(tags))
+
+	assert.Equal(t, "test.httpcall", name)
+	assert.Equal(t, "method:GET", tags[0])
+}
+
+func TestSplitNameAndTagsMultipleTag(t *testing.T) {
+	globalTags := []string{"globaltag:true"}
+	reporter := &Reporter{
+		Registry: metrics.DefaultRegistry,
+		tags:     globalTags,
+	}
+
+	var metricName = "test.httpcall[method:GET]"
+
+	name, tags := reporter.splitNameAndTags(metricName)
+	assert.NotNil(t, name, "name")
+	assert.NotNil(t, tags, "tags")
+	//expect two tags: the global tag and the metric level tag
+	assert.Equal(t, 2, len(tags))
+
+	assert.Equal(t, "test.httpcall", name)
+	assert.Equal(t, "method:GET", tags[0])
+	assert.Equal(t, "globaltag:true", tags[1])
+}