Add Kafka msgpack support

go.mod

@@ -41,6 +41,7 @@ require (
 	github.com/sevlyar/go-daemon v0.1.6-0.20210508104436-15bb82c8ea3c
 	github.com/stretchr/testify v1.6.1
 	github.com/syndtr/goleveldb v0.0.0-20180815032940-ae2bd5eed72d
+	github.com/vmihailenco/msgpack/v5 v5.3.5
 	go.opentelemetry.io/otel v0.9.0
 	go.opentelemetry.io/otel/exporters/trace/jaeger v0.9.0
 	go.uber.org/atomic v1.3.2 // indirect

go.sum

@@ -201,6 +201,10 @@ github.com/stretchr/testify v1.6.1 h1:hDPOHmpOpP40lSULcqw7IrRb/u7w6RpDC9399XyoNd
 github.com/stretchr/testify v1.6.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
 github.com/syndtr/goleveldb v0.0.0-20180815032940-ae2bd5eed72d h1:4J9HCZVpvDmj2tiKGSTUnb3Ok/9CEQb9oqu9LHKQQpc=
 github.com/syndtr/goleveldb v0.0.0-20180815032940-ae2bd5eed72d/go.mod h1:Z4AUp2Km+PwemOoO/VB5AOx9XSsIItzFjoJlOSiYmn0=
+github.com/vmihailenco/msgpack/v5 v5.3.5 h1:5gO0H1iULLWGhs2H5tbAHIZTV8/cYafcFOr9znI5mJU=
+github.com/vmihailenco/msgpack/v5 v5.3.5/go.mod h1:7xyJ9e+0+9SaZT0Wt1RGleJXzli6Q/V5KbhBonMG9jc=
+github.com/vmihailenco/tagparser/v2 v2.0.0 h1:y09buUbR+b5aycVFQs/g70pqKVZNBmxwAhO7/IwNM9g=
+github.com/vmihailenco/tagparser/v2 v2.0.0/go.mod h1:Wri+At7QHww0WTrCBeu4J6bNtoV6mEfg5OIWRZA9qds=
 github.com/yuin/goldmark v1.1.25/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9decYSb74=
 go.opencensus.io v0.21.0/go.mod h1:mSImk1erAIZhrmZN+AvHh14ztQfjbGwt4TtuofqLduU=
 go.opencensus.io v0.22.0/go.mod h1:+kGneAE2xo2IficOXnaByMWTGM9T73dGwxeWcUqIpI8=

receiver/kafka/kafka.go

@@ -66,7 +66,7 @@ func (o *Offset) UnmarshalText(text []byte) error {
 	return nil
 }
 
-var supportedProtocols = []string{"plain", "protobuf", "pickle"}
+var supportedProtocols = []string{"plain", "protobuf", "pickle", "msgpack"}
 
 // Protocol is a special type to allow user to define wire protocol in Config file as a simple text.
 type Protocol int
@@ -80,6 +80,8 @@ func (p *Protocol) MarshalText() ([]byte, error) {
 		return []byte("protobuf"), nil
 	case ProtocolPickle:
 		return []byte("pickle"), nil
+	case ProtocolMsgPack:
+		return []byte("msgpack"), nil
 	}
 	return nil, fmt.Errorf("Unsupported offset type %v, supported offsets: %v", p, supportedProtocols)
 }
@@ -95,6 +97,8 @@ func (p *Protocol) UnmarshalText(text []byte) error {
 		*p = ProtocolProtobuf
 	case "pickle":
 		*p = ProtocolPickle
+	case "msgpack":
+		*p = ProtocolMsgPack
 	default:
 		return fmt.Errorf("Unsupported protocol type %v, supported: %v", protocolName, supportedProtocols)
 	}
@@ -110,6 +114,8 @@ func (p *Protocol) ToString() string {
 		return "protobuf"
 	case ProtocolPickle:
 		return "pickle"
+	case ProtocolMsgPack:
+		return "msgpack"
 	}
 	return "unsupported"
 }
@@ -126,6 +132,8 @@ const (
 	ProtocolProtobuf = 1
 	// ProtocolPickle represents pickled messages
 	ProtocolPickle = 2
+	// ProtocolMsgPack represents msgpack messages
+	ProtocolMsgPack = 3
 )
 
 // Duration wrapper time.Duration for TOML
@@ -477,6 +485,8 @@ func (rcv *Kafka) worker() {
 		protocolParser = parse.Plain
 	case ProtocolPickle:
 		protocolParser = parse.Pickle
+	case ProtocolMsgPack:
+		protocolParser = parse.Msgpack
 	}
 	for {
 		select {
@@ -537,5 +547,5 @@ func (rcv *Kafka) worker() {
 }
 
 // InitPrometheus is a stub for the receiver prom metrics. Required to satisfy Receiver interface.
-func (rcv *Kafka) InitPrometheus(reg prometheus.Registerer) {
+func (*Kafka) InitPrometheus(_ prometheus.Registerer) {
 }

receiver/parse/msgpack.go

@@ -0,0 +1,35 @@
+package parse
+
+import (
+	"errors"
+
+	"github.com/go-graphite/go-carbon/points"
+	"github.com/vmihailenco/msgpack/v5"
+)
+
+// Datapoint loads a msgpack data
+type Datapoint struct {
+	Name  string  `json:"Name"`
+	Value float64 `json:"Value"`
+	Time  int64   `json:"Time"`
+}
+
+// Msgpack is used to unpack metrics produced by
+// carbon-relay-ng
+func Msgpack(body []byte) ([]*points.Points, error) {
+	result := make([]*points.Points, 0)
+
+	var d Datapoint
+	err := msgpack.Unmarshal(body, &d)
+	if err != nil {
+		return result, err
+	}
+
+	if d.Name == "" {
+		err = errors.New("Empty metric name")
+		return result, err
+	}
+
+	result = append(result, points.OnePoint(d.Name, d.Value, d.Time))
+	return result, err
+}

receiver/parse/msgpack_test.go

@@ -0,0 +1,39 @@
+package parse
+
+import (
+	"testing"
+
+	"github.com/go-graphite/go-carbon/points"
+	"github.com/vmihailenco/msgpack/v5"
+)
+
+func TestMsgpack(t *testing.T) {
+	var testCaseOK = Datapoint{
+		Name:  "test.case.number.1",
+		Value: 60.2,
+		Time:  1423931224,
+	}
+
+	var testCaseEmptyName = Datapoint{
+		Name:  "",
+		Value: 60.2,
+		Time:  1423931224,
+	}
+
+	msgOk, _ := msgpack.Marshal(testCaseOK)
+	msgFail, _ := msgpack.Marshal(testCaseEmptyName)
+
+	msgpacks := []testcase{
+		{"One metric with one datapoint",
+			msgOk,
+			[]*points.Points{points.OnePoint("test.case.number.1", 60.2, 1423931224)},
+			false,
+		},
+		{"Empty metric name with one datapoint",
+			msgFail,
+			[]*points.Points{points.OnePoint("", 60.2, 1423931224)},
+			true,
+		},
+	}
+	run(t, msgpacks, Msgpack)
+}