Add resource support to dogstatsd exporter (#13)

* Add resource support to dogstatsd

* Mod tidy

exporters/metric/dogstatsd/dogstatsd.go

@@ -21,13 +21,13 @@ import (
 	"github.com/open-telemetry/opentelemetry-go-contrib/exporters/metric/dogstatsd/internal/statsd"
 	"go.opentelemetry.io/otel/api/global"
 	"go.opentelemetry.io/otel/api/metric"
+	export "go.opentelemetry.io/otel/sdk/export/metric"
 	"go.opentelemetry.io/otel/sdk/metric/aggregator/array"
 	"go.opentelemetry.io/otel/sdk/metric/aggregator/lastvalue"
 	"go.opentelemetry.io/otel/sdk/metric/aggregator/sum"
-
-	export "go.opentelemetry.io/otel/sdk/export/metric"
 	"go.opentelemetry.io/otel/sdk/metric/batcher/ungrouped"
 	"go.opentelemetry.io/otel/sdk/metric/controller/push"
+	"go.opentelemetry.io/otel/sdk/resource"
 )
 
 type (
@@ -44,7 +44,7 @@ type (
 	Exporter struct {
 		*statsd.Exporter
 
-		labelEncoder *statsd.LabelEncoder
+		labelEncoder *LabelEncoder
 	}
 )
 
@@ -54,8 +54,17 @@ var (
 
 // NewRawExporter returns a new Dogstatsd-syntax exporter for use in a pipeline.
 func NewRawExporter(config Config) (*Exporter, error) {
+	// TODO: Remove the resource value set from the Config here when
+	// https://github.com/open-telemetry/opentelemetry-go/pull/640
+	// and 641 are released.  The resources will be received on
+	// the first call to Export().
+	res := config.Resource
+	if res == nil {
+		res = resource.New()
+	}
+
 	exp := &Exporter{
-		labelEncoder: statsd.NewLabelEncoder(),
+		labelEncoder: NewLabelEncoder(res),
 	}
 
 	var err error

exporters/metric/dogstatsd/dogstatsd_test.go

@@ -20,21 +20,21 @@ import (
 	"testing"
 
 	"github.com/open-telemetry/opentelemetry-go-contrib/exporters/metric/dogstatsd"
-	"github.com/open-telemetry/opentelemetry-go-contrib/exporters/metric/dogstatsd/internal/statsd"
 	"github.com/stretchr/testify/require"
 
 	"go.opentelemetry.io/otel/api/core"
 	"go.opentelemetry.io/otel/api/key"
 	"go.opentelemetry.io/otel/api/metric"
 	"go.opentelemetry.io/otel/exporters/metric/test"
 	"go.opentelemetry.io/otel/sdk/metric/aggregator/sum"
+	"go.opentelemetry.io/otel/sdk/resource"
 )
 
 // TestDogstatsLabels that labels are formatted in the correct style,
 // whether or not the provided labels were encoded by a statsd label
 // encoder.
 func TestDogstatsLabels(t *testing.T) {
-	encoder := statsd.NewLabelEncoder()
+	encoder := dogstatsd.NewLabelEncoder(resource.New(key.String("R", "S")))
 	ctx := context.Background()
 	checkpointSet := test.NewCheckpointSet(encoder)
 
@@ -54,5 +54,5 @@ func TestDogstatsLabels(t *testing.T) {
 	err = exp.Export(ctx, checkpointSet)
 	require.Nil(t, err)
 
-	require.Equal(t, "test.name:123|c|#A:B\n", buf.String())
+	require.Equal(t, "test.name:123|c|#R:S,A:B\n", buf.String())
 }

exporters/metric/dogstatsd/internal/statsd/conn.go

@@ -31,6 +31,7 @@ import (
 	"go.opentelemetry.io/otel/api/unit"
 	export "go.opentelemetry.io/otel/sdk/export/metric"
 	"go.opentelemetry.io/otel/sdk/export/metric/aggregator"
+	"go.opentelemetry.io/otel/sdk/resource"
 )
 
 type (
@@ -50,6 +51,12 @@ type (
 		// MaxPacketSize this limits the packet size for packet-oriented transports.
 		MaxPacketSize int
 
+		// Resource WILL BE REMOVED AFTER RESOURCES ARE ADDED
+		// TO THE EXPORT APIs.  TODO: Remove this when Export()
+		// passes the Resource.  See:
+		// https://github.com/open-telemetry/opentelemetry-go/pull/640
+		Resource *resource.Resource
+
 		// TODO support Dial and Write timeouts
 	}
 

exporters/metric/dogstatsd/internal/statsd/conn_test.go

@@ -35,7 +35,7 @@ import (
 
 // withTagsAdapter tests a dogstatsd-style statsd exporter.
 type withTagsAdapter struct {
-	*statsd.LabelEncoder
+	export.LabelEncoder
 }
 
 func (*withTagsAdapter) AppendName(rec export.Record, buf *bytes.Buffer) {
@@ -44,12 +44,14 @@ func (*withTagsAdapter) AppendName(rec export.Record, buf *bytes.Buffer) {
 
 func (ta *withTagsAdapter) AppendTags(rec export.Record, buf *bytes.Buffer) {
 	encoded := rec.Labels().Encoded(ta.LabelEncoder)
+	_, _ = buf.WriteString("++")
 	_, _ = buf.WriteString(encoded)
 }
 
 func newWithTagsAdapter() *withTagsAdapter {
 	return &withTagsAdapter{
-		statsd.NewLabelEncoder(),
+		// Note: This uses non-statsd syntax.  (No problem.)
+		export.NewDefaultLabelEncoder(),
 	}
 }
 
@@ -93,10 +95,10 @@ func TestBasicFormat(t *testing.T) {
 
 	for _, ao := range []adapterOutput{{
 		adapter: newWithTagsAdapter(),
-		expected: `counter:%s|c|#A:B,C:D
-observer:%s|g|#A:B,C:D
-measure:%s|h|#A:B,C:D
-timer:%s|ms|#A:B,C:D
+		expected: `counter:%s|c++A=B,C=D
+observer:%s|g++A=B,C=D
+measure:%s|h++A=B,C=D
+timer:%s|ms++A=B,C=D
 `}, {
 		adapter: newNoTagsAdapter(),
 		expected: `counter.B.D:%s|c
@@ -297,7 +299,7 @@ func TestPacketSplit(t *testing.T) {
 				offset += nkeys
 				iter := export.LabelSlice(labels).Iter()
 				encoded := adapter.LabelEncoder.Encode(iter)
-				expect := fmt.Sprint("counter:100|c", encoded, "\n")
+				expect := fmt.Sprint("counter:100|c++", encoded, "\n")
 				expected = append(expected, expect)
 				checkpointSet.AddCounter(&desc, 100, labels...)
 			})

exporters/metric/dogstatsd/internal/statsd/labels.go → exporters/metric/dogstatsd/labels.go

@@ -12,13 +12,16 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package statsd
+package dogstatsd
 
 import (
 	"bytes"
+	"sort"
 	"sync"
 
+	"go.opentelemetry.io/otel/api/core"
 	export "go.opentelemetry.io/otel/sdk/export/metric"
+	"go.opentelemetry.io/otel/sdk/resource"
 )
 
 // LabelEncoder encodes metric labels in the dogstatsd syntax.
@@ -28,21 +31,28 @@ import (
 //
 // https://github.com/stripe/veneur/blob/master/sinks/datadog/datadog.go
 type LabelEncoder struct {
-	pool sync.Pool
+	pool      sync.Pool
+	resources []core.KeyValue
 }
 
 var _ export.LabelEncoder = &LabelEncoder{}
 var leID = export.NewLabelEncoderID()
 
 // NewLabelEncoder returns a new encoder for dogstatsd-syntax metric
 // labels.
-func NewLabelEncoder() *LabelEncoder {
+func NewLabelEncoder(resource *resource.Resource) *LabelEncoder {
+	attrs := resource.Attributes()
+	sort.Slice(attrs[:], func(i, j int) bool {
+		return attrs[i].Key < attrs[j].Key
+	})
+
 	return &LabelEncoder{
 		pool: sync.Pool{
 			New: func() interface{} {
 				return &bytes.Buffer{}
 			},
 		},
+		resources: attrs,
 	}
 }
 
@@ -52,19 +62,26 @@ func (e *LabelEncoder) Encode(iter export.LabelIterator) string {
 	defer e.pool.Put(buf)
 	buf.Reset()
 
-	delimiter := "|#"
-
+	for _, kv := range e.resources {
+		e.encodeOne(buf, kv)
+	}
 	for iter.Next() {
-		kv := iter.Label()
-		_, _ = buf.WriteString(delimiter)
-		_, _ = buf.WriteString(string(kv.Key))
-		_, _ = buf.WriteRune(':')
-		_, _ = buf.WriteString(kv.Value.Emit())
-		delimiter = ","
+		e.encodeOne(buf, iter.Label())
 	}
 	return buf.String()
 }
 
+func (e *LabelEncoder) encodeOne(buf *bytes.Buffer, kv core.KeyValue) {
+	if buf.Len() == 0 {
+		_, _ = buf.WriteString("|#")
+	} else {
+		_, _ = buf.WriteRune(',')
+	}
+	_, _ = buf.WriteString(string(kv.Key))
+	_, _ = buf.WriteRune(':')
+	_, _ = buf.WriteString(kv.Value.Emit())
+}
+
 func (*LabelEncoder) ID() int64 {
 	return leID
 }

exporters/metric/dogstatsd/internal/statsd/labels_test.go → exporters/metric/dogstatsd/labels_test.go

@@ -12,34 +12,46 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package statsd_test
+package dogstatsd_test
 
 import (
 	"testing"
 
-	"github.com/open-telemetry/opentelemetry-go-contrib/exporters/metric/dogstatsd/internal/statsd"
+	"github.com/open-telemetry/opentelemetry-go-contrib/exporters/metric/dogstatsd"
 	"github.com/stretchr/testify/require"
 
 	"go.opentelemetry.io/otel/api/core"
 	"go.opentelemetry.io/otel/api/key"
 	export "go.opentelemetry.io/otel/sdk/export/metric"
+	"go.opentelemetry.io/otel/sdk/resource"
 )
 
 var testLabels = []core.KeyValue{
-	key.New("A").String("B"),
-	key.New("C").String("D"),
-	key.New("E").Float64(1.5),
+	key.String("A", "B"),
+	key.String("C", "D"),
+	key.Float64("E", 1.5),
+}
+
+var testResources = []core.KeyValue{
+	key.String("R1", "V1"),
+	key.String("R2", "V2"),
 }
 
 func TestLabelSyntax(t *testing.T) {
-	encoder := statsd.NewLabelEncoder()
+	encoder := dogstatsd.NewLabelEncoder(resource.New())
 
 	require.Equal(t, `|#A:B,C:D,E:1.5`, encoder.Encode(export.LabelSlice(testLabels).Iter()))
 
 	kvs := []core.KeyValue{
-		key.New("A").String("B"),
+		key.String("A", "B"),
 	}
 	require.Equal(t, `|#A:B`, encoder.Encode(export.LabelSlice(kvs).Iter()))
 
 	require.Equal(t, "", encoder.Encode(export.LabelSlice(nil).Iter()))
 }
+
+func TestLabelResources(t *testing.T) {
+	encoder := dogstatsd.NewLabelEncoder(resource.New(testResources...))
+
+	require.Equal(t, `|#R1:V1,R2:V2,A:B,C:D,E:1.5`, encoder.Encode(export.LabelSlice(testLabels).Iter()))
+}