[exporter/otlphttp] added support for configurable telemetry encoding

.chloggen/otlphttp-json-encoding.yaml

@@ -0,0 +1,25 @@
+# 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. otlpreceiver)
+component: otlphttpexporter
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: Add support for json content encoding when exporting telemetry
+
+# One or more tracking issues or pull requests related to the change
+issues: [6945]
+
+# (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:
+
+# 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: []

exporter/otlphttpexporter/README.md

@@ -37,6 +37,7 @@ The following settings can be optionally configured:
 - `timeout` (default = 30s): HTTP request time limit. For details see https://golang.org/pkg/net/http/#Client
 - `read_buffer_size` (default = 0): ReadBufferSize for HTTP client.
 - `write_buffer_size` (default = 512 * 1024): WriteBufferSize for HTTP client.
+- `encoding` (default = proto): The encoding to use for the messages (valid options: `proto`, `json`)
 
 Example:
 
@@ -55,5 +56,14 @@ exporters:
     compression: none
 ```
 
+By default `proto` encoding is used, to change the content encoding of the message configure it as follows:
+
+```yaml
+exporters:
+  otlphttp:
+    ...
+    encoding: json
+```
+
 The full list of settings exposed for this exporter are documented [here](./config.go)
 with detailed sample configurations [here](./testdata/config.yaml).

exporter/otlphttpexporter/config.go

@@ -4,14 +4,45 @@
 package otlphttpexporter // import "go.opentelemetry.io/collector/exporter/otlphttpexporter"
 
 import (
+	"encoding"
 	"errors"
+	"fmt"
 
 	"go.opentelemetry.io/collector/component"
 	"go.opentelemetry.io/collector/config/confighttp"
 	"go.opentelemetry.io/collector/config/configretry"
 	"go.opentelemetry.io/collector/exporter/exporterhelper"
 )
 
+// EncodingType defines the type for content encoding
+type EncodingType string
+
+const (
+	EncodingProto EncodingType = "proto"
+	EncodingJSON  EncodingType = "json"
+)
+
+var _ encoding.TextUnmarshaler = (*EncodingType)(nil)
+
+// UnmarshalText unmarshalls text to an EncodingType.
+func (e *EncodingType) UnmarshalText(text []byte) error {
+	if e == nil {
+		return errors.New("cannot unmarshal to a nil *EncodingType")
+	}
+
+	str := string(text)
+	switch str {
+	case string(EncodingProto):
+		*e = EncodingProto
+	case string(EncodingJSON):
+		*e = EncodingJSON
+	default:
+		return fmt.Errorf("invalid encoding type: %s", str)
+	}
+
+	return nil
+}
+
 // Config defines configuration for OTLP/HTTP exporter.
 type Config struct {
 	confighttp.HTTPClientConfig `mapstructure:",squash"`     // squash ensures fields are correctly decoded in embedded struct.
@@ -26,6 +57,9 @@
 
 	// The URL to send logs to. If omitted the Endpoint + "/v1/logs" will be used.
 	LogsEndpoint string `mapstructure:"logs_endpoint"`
+
+	// The encoding to export telemetry (default: "proto")
+	Encoding EncodingType `mapstructure:"encoding"`
 }
 
 var _ component.Config = (*Config)(nil)

exporter/otlphttpexporter/config_test.go

@@ -51,6 +51,7 @@ func TestUnmarshalConfig(t *testing.T) {
 				NumConsumers: 2,
 				QueueSize:    10,
 			},
+			Encoding: EncodingProto,
 			HTTPClientConfig: confighttp.HTTPClientConfig{
 				Headers: map[string]configopaque.String{
 					"can you have a . here?": "F0000000-0000-0000-0000-000000000000",
@@ -73,3 +74,57 @@ func TestUnmarshalConfig(t *testing.T) {
 			},
 		}, cfg)
 }
+
+func TestUnmarshalConfigInvalidEncoding(t *testing.T) {
+	cm, err := confmaptest.LoadConf(filepath.Join("testdata", "bad_invalid_encoding.yaml"))
+	require.NoError(t, err)
+	factory := NewFactory()
+	cfg := factory.CreateDefaultConfig()
+	assert.Error(t, component.UnmarshalConfig(cm, cfg))
+}
+
+func TestUnmarshalEncoding(t *testing.T) {
+	tests := []struct {
+		name          string
+		encodingBytes []byte
+		expected      EncodingType
+		shouldError   bool
+	}{
+		{
+			name:          "UnmarshalEncodingProto",
+			encodingBytes: []byte("proto"),
+			expected:      EncodingProto,
+			shouldError:   false,
+		},
+		{
+			name:          "UnmarshalEncodingJson",
+			encodingBytes: []byte("json"),
+			expected:      EncodingJSON,
+			shouldError:   false,
+		},
+		{
+			name:          "UnmarshalEmptyEncoding",
+			encodingBytes: []byte(""),
+			shouldError:   true,
+		},
+		{
+			name:          "UnmarshalInvalidEncoding",
+			encodingBytes: []byte("invalid"),
+			shouldError:   true,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			var encoding EncodingType
+			err := encoding.UnmarshalText(tt.encodingBytes)
+
+			if tt.shouldError {
+				assert.Error(t, err)
+			} else {
+				assert.NoError(t, err)
+				assert.Equal(t, tt.expected, encoding)
+			}
+		})
+	}
+}

exporter/otlphttpexporter/factory.go

@@ -36,6 +36,7 @@ func createDefaultConfig() component.Config {
 	return &Config{
 		RetryConfig: configretry.NewDefaultBackOffConfig(),
 		QueueConfig: exporterhelper.NewDefaultQueueSettings(),
+		Encoding:    EncodingProto,
 		HTTPClientConfig: confighttp.HTTPClientConfig{
 			Endpoint: "",
 			Timeout:  30 * time.Second,

exporter/otlphttpexporter/factory_test.go

@@ -36,6 +36,7 @@ func TestCreateDefaultConfig(t *testing.T) {
 	assert.Equal(t, ocfg.RetryConfig.MaxInterval, 30*time.Second, "default retry MaxInterval")
 	assert.Equal(t, ocfg.QueueConfig.Enabled, true, "default sending queue is enabled")
 	assert.Equal(t, ocfg.Compression, configcompression.Gzip)
+	assert.Equal(t, ocfg.Encoding, EncodingProto)
 }
 
 func TestCreateMetricsExporter(t *testing.T) {
@@ -154,6 +155,20 @@ func TestCreateTracesExporter(t *testing.T) {
 				},
 			},
 		},
+		{
+			name: "ProtoEncoding",
+			config: &Config{
+				Encoding:         EncodingProto,
+				HTTPClientConfig: confighttp.HTTPClientConfig{Endpoint: endpoint},
+			},
+		},
+		{
+			name: "JSONEncoding",
+			config: &Config{
+				Encoding:         EncodingJSON,
+				HTTPClientConfig: confighttp.HTTPClientConfig{Endpoint: endpoint},
+			},
+		},
 	}
 
 	for _, tt := range tests {