[receiver/kafkareceiver] Add otlp_json support in kafka receiver

.chloggen/otlp_logs.yaml

@@ -0,0 +1,29 @@
+# Use this changelog template to create an entry for release notes.
+
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: enhancement
+
+# The name of the component, or a single word describing the area of concern, (e.g. filelogreceiver)
+component: kafkareceiver
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note:  "Add support for `otlp_json` encoding to Kafka receiver. The payload is deserialized into OpenTelemetry traces using JSON format."
+
+# Mandatory: One or more tracking issues related to the change. You can use the PR number here if no issue exists.
+issues: [33627]
+
+# (Optional) One or more lines of additional information to render under the primary note.
+# These lines will be padded with 2 spaces and then inserted directly into the document.
+# Use pipe (|) for multiline entries.
+subtext: |
+  This encoding allows the Kafka receiver to handle trace data in JSON format,
+  enabling integration with systems that export traces as JSON-encoded data.
+
+# If your change doesn't affect end users or the exported elements of any package,
+# you should instead start your pull request title with [chore] or use the "Skip Changelog" label.
+# Optional: The change log or logs in which this entry should be included.
+# e.g. '[user]' or '[user, api]'
+# Include 'user' if the change is relevant to end users.
+# Include 'api' if there is a change to a library API.
+# Default: '[user]'
+change_logs: [user]

receiver/kafkareceiver/README.md

@@ -31,6 +31,7 @@ The following settings can be optionally configured:
   Only one telemetry type may be used for a given topic.
 - `encoding` (default = otlp_proto): The encoding of the payload received from kafka. Available encodings:
   - `otlp_proto`: the payload is deserialized to `ExportTraceServiceRequest`, `ExportLogsServiceRequest` or `ExportMetricsServiceRequest` respectively.
+  - `otlp_json`: the payload is deserialized to `ExportTraceServiceRequest` `ExportLogsServiceRequest` or `ExportMetricsServiceRequest` respectively using JSON encoding
   - `jaeger_proto`: the payload is deserialized to a single Jaeger proto `Span`.
   - `jaeger_json`: the payload is deserialized to a single Jaeger JSON Span using `jsonpb`.
   - `zipkin_proto`: the payload is deserialized into a list of Zipkin proto spans.

receiver/kafkareceiver/unmarshaler.go

@@ -17,7 +17,6 @@ import (
 type TracesUnmarshaler interface {
 	// Unmarshal deserializes the message body into traces.
 	Unmarshal([]byte) (ptrace.Traces, error)
-
 	// Encoding of the serialized messages.
 	Encoding() string
 }
@@ -26,7 +25,6 @@ type TracesUnmarshaler interface {
 type MetricsUnmarshaler interface {
 	// Unmarshal deserializes the message body into traces
 	Unmarshal([]byte) (pmetric.Metrics, error)
-
 	// Encoding of the serialized messages
 	Encoding() string
 }
@@ -35,28 +33,28 @@ type MetricsUnmarshaler interface {
 type LogsUnmarshaler interface {
 	// Unmarshal deserializes the message body into traces.
 	Unmarshal([]byte) (plog.Logs, error)
-
 	// Encoding of the serialized messages.
 	Encoding() string
 }
 
 type LogsUnmarshalerWithEnc interface {
 	LogsUnmarshaler
-
 	// WithEnc sets the character encoding (UTF-8, GBK, etc.) of the unmarshaler.
 	WithEnc(string) (LogsUnmarshalerWithEnc, error)
 }
 
 // defaultTracesUnmarshalers returns map of supported encodings with TracesUnmarshaler.
 func defaultTracesUnmarshalers() map[string]TracesUnmarshaler {
 	otlpPb := newPdataTracesUnmarshaler(&ptrace.ProtoUnmarshaler{}, defaultEncoding)
+	otlpJSON := newPdataTracesUnmarshaler(&ptrace.JSONUnmarshaler{}, "otlp_json")
 	jaegerProto := jaegerProtoSpanUnmarshaler{}
 	jaegerJSON := jaegerJSONSpanUnmarshaler{}
 	zipkinProto := newPdataTracesUnmarshaler(zipkinv2.NewProtobufTracesUnmarshaler(false, false), "zipkin_proto")
 	zipkinJSON := newPdataTracesUnmarshaler(zipkinv2.NewJSONTracesUnmarshaler(false), "zipkin_json")
 	zipkinThrift := newPdataTracesUnmarshaler(zipkinv1.NewThriftTracesUnmarshaler(), "zipkin_thrift")
 	return map[string]TracesUnmarshaler{
 		otlpPb.Encoding():       otlpPb,
+		otlpJSON.Encoding():     otlpJSON,
 		jaegerProto.Encoding():  jaegerProto,
 		jaegerJSON.Encoding():   jaegerJSON,
 		zipkinProto.Encoding():  zipkinProto,
@@ -67,20 +65,24 @@ func defaultTracesUnmarshalers() map[string]TracesUnmarshaler {
 
 func defaultMetricsUnmarshalers() map[string]MetricsUnmarshaler {
 	otlpPb := newPdataMetricsUnmarshaler(&pmetric.ProtoUnmarshaler{}, defaultEncoding)
+	otlpJSON := newPdataMetricsUnmarshaler(&pmetric.JSONUnmarshaler{}, "otlp_json")
 	return map[string]MetricsUnmarshaler{
-		otlpPb.Encoding(): otlpPb,
+		otlpPb.Encoding():   otlpPb,
+		otlpJSON.Encoding(): otlpJSON,
 	}
 }
 
 func defaultLogsUnmarshalers(version string, logger *zap.Logger) map[string]LogsUnmarshaler {
 	azureResourceLogs := newAzureResourceLogsUnmarshaler(version, logger)
 	otlpPb := newPdataLogsUnmarshaler(&plog.ProtoUnmarshaler{}, defaultEncoding)
+	otlpJSON := newPdataLogsUnmarshaler(&plog.JSONUnmarshaler{}, "otlp_json")
 	raw := newRawLogsUnmarshaler()
 	text := newTextLogsUnmarshaler()
 	json := newJSONLogsUnmarshaler()
 	return map[string]LogsUnmarshaler{
 		azureResourceLogs.Encoding(): azureResourceLogs,
 		otlpPb.Encoding():            otlpPb,
+		otlpJSON.Encoding():          otlpJSON,
 		raw.Encoding():               raw,
 		text.Encoding():              text,
 		json.Encoding():              json,

receiver/kafkareceiver/unmarshaler_test.go

@@ -14,6 +14,7 @@ import (
 func TestDefaultTracesUnMarshaler(t *testing.T) {
 	expectedEncodings := []string{
 		"otlp_proto",
+		"otlp_json",
 		"jaeger_proto",
 		"jaeger_json",
 		"zipkin_proto",
@@ -34,6 +35,7 @@ func TestDefaultTracesUnMarshaler(t *testing.T) {
 func TestDefaultMetricsUnMarshaler(t *testing.T) {
 	expectedEncodings := []string{
 		"otlp_proto",
+		"otlp_json",
 	}
 	marshalers := defaultMetricsUnmarshalers()
 	assert.Equal(t, len(expectedEncodings), len(marshalers))
@@ -49,6 +51,7 @@ func TestDefaultMetricsUnMarshaler(t *testing.T) {
 func TestDefaultLogsUnMarshaler(t *testing.T) {
 	expectedEncodings := []string{
 		"otlp_proto",
+		"otlp_json",
 		"raw",
 		"text",
 		"json",