feat: Support Exporter Metadata

providers/go-feature-flag/pkg/controller/goff_api.go

@@ -22,6 +22,8 @@ type GoFeatureFlagApiOptions struct {
 	// (This feature is available only if you are using GO Feature Flag relay proxy v1.7.0 or above)
 	// Default: null
 	APIKey string
+	// ExporterMetadata (optional) If we set metadata, it will be sent with every data collection requests along with the events.
+	ExporterMetadata map[string]interface{}
 }
 
 type GoFeatureFlagAPI struct {
@@ -39,9 +41,10 @@ func NewGoFeatureFlagAPI(options GoFeatureFlagApiOptions) GoFeatureFlagAPI {
 func (g *GoFeatureFlagAPI) CollectData(events []model.FeatureEvent) error {
 	u, _ := url.Parse(g.options.Endpoint)
 	u.Path = path.Join(u.Path, "v1", "data", "collector")
+
 	reqBody := model.DataCollectorRequest{
 		Events: events,
-		Meta:   map[string]string{"provider": "go", "openfeature": "true"},
+		Meta:   g.options.ExporterMetadata,
 	}
 
 	jsonData, err := json.Marshal(reqBody)

providers/go-feature-flag/pkg/controller/goff_api_test.go

@@ -28,8 +28,9 @@ func Test_CollectDataAPI(t *testing.T) {
 			name:    "Valid api call",
 			wantErr: assert.NoError,
 			options: controller.GoFeatureFlagApiOptions{
-				Endpoint: "http://localhost:1031",
-				APIKey:   "",
+				Endpoint:         "http://localhost:1031",
+				APIKey:           "",
+				ExporterMetadata: map[string]interface{}{"openfeature": true, "provider": "go"},
 			},
 			events: []model.FeatureEvent{
 				{
@@ -68,14 +69,15 @@ func Test_CollectDataAPI(t *testing.T) {
 				headers.Set(controller.ContentTypeHeader, controller.ApplicationJson)
 				return headers
 			}(),
-			wantReqBody: "{\"events\":[{\"kind\":\"feature\",\"contextKind\":\"user\",\"userKey\":\"ABCD\",\"creationDate\":1722266324,\"key\":\"random-key\",\"variation\":\"variationA\",\"value\":\"YO\",\"default\":false,\"version\":\"\",\"source\":\"SERVER\"},{\"kind\":\"feature\",\"contextKind\":\"user\",\"userKey\":\"EFGH\",\"creationDate\":1722266324,\"key\":\"random-key\",\"variation\":\"variationA\",\"value\":\"YO\",\"default\":false,\"version\":\"\",\"source\":\"SERVER\"}],\"meta\":{\"openfeature\":\"true\",\"provider\":\"go\"}}",
+			wantReqBody: "{\"events\":[{\"kind\":\"feature\",\"contextKind\":\"user\",\"userKey\":\"ABCD\",\"creationDate\":1722266324,\"key\":\"random-key\",\"variation\":\"variationA\",\"value\":\"YO\",\"default\":false,\"version\":\"\",\"source\":\"SERVER\"},{\"kind\":\"feature\",\"contextKind\":\"user\",\"userKey\":\"EFGH\",\"creationDate\":1722266324,\"key\":\"random-key\",\"variation\":\"variationA\",\"value\":\"YO\",\"default\":false,\"version\":\"\",\"source\":\"SERVER\"}],\"meta\":{\"openfeature\":true,\"provider\":\"go\"}}",
 		},
 		{
 			name:    "Valid api call with API Key",
 			wantErr: assert.NoError,
 			options: controller.GoFeatureFlagApiOptions{
-				Endpoint: "http://localhost:1031",
-				APIKey:   "my-key",
+				Endpoint:         "http://localhost:1031",
+				APIKey:           "my-key",
+				ExporterMetadata: map[string]interface{}{"openfeature": true, "provider": "go"},
 			},
 			events: []model.FeatureEvent{
 				{
@@ -115,7 +117,7 @@ func Test_CollectDataAPI(t *testing.T) {
 				headers.Set(controller.AuthorizationHeader, controller.BearerPrefix+"my-key")
 				return headers
 			}(),
-			wantReqBody: "{\"events\":[{\"kind\":\"feature\",\"contextKind\":\"user\",\"userKey\":\"ABCD\",\"creationDate\":1722266324,\"key\":\"random-key\",\"variation\":\"variationA\",\"value\":\"YO\",\"default\":false,\"version\":\"\",\"source\":\"SERVER\"},{\"kind\":\"feature\",\"contextKind\":\"user\",\"userKey\":\"EFGH\",\"creationDate\":1722266324,\"key\":\"random-key\",\"variation\":\"variationA\",\"value\":\"YO\",\"default\":false,\"version\":\"\",\"source\":\"SERVER\"}],\"meta\":{\"openfeature\":\"true\",\"provider\":\"go\"}}",
+			wantReqBody: "{\"events\":[{\"kind\":\"feature\",\"contextKind\":\"user\",\"userKey\":\"ABCD\",\"creationDate\":1722266324,\"key\":\"random-key\",\"variation\":\"variationA\",\"value\":\"YO\",\"default\":false,\"version\":\"\",\"source\":\"SERVER\"},{\"kind\":\"feature\",\"contextKind\":\"user\",\"userKey\":\"EFGH\",\"creationDate\":1722266324,\"key\":\"random-key\",\"variation\":\"variationA\",\"value\":\"YO\",\"default\":false,\"version\":\"\",\"source\":\"SERVER\"}],\"meta\":{\"openfeature\":true,\"provider\":\"go\"}}",
 		},
 		{
 			name:    "Request failed",

providers/go-feature-flag/pkg/model/data_collector_request.go

@@ -1,6 +1,6 @@
 package model
 
 type DataCollectorRequest struct {
-	Events []FeatureEvent    `json:"events"`
-	Meta   map[string]string `json:"meta"`
+	Events []FeatureEvent         `json:"events"`
+	Meta   map[string]interface{} `json:"meta"`
 }

providers/go-feature-flag/pkg/provider.go

@@ -53,10 +53,19 @@ func NewProviderWithContext(ctx context.Context, options ProviderOptions) (*Prov
 	}))
 	ofrepProvider := ofrep.NewProvider(options.Endpoint, ofrepOptions...)
 	cacheCtrl := controller.NewCache(options.FlagCacheSize, options.FlagCacheTTL, options.DisableCache)
+
+	// Adding metadata to the GO Feature Flag provider to be sent to the exporter
+	if options.ExporterMetadata == nil {
+		options.ExporterMetadata = make(map[string]interface{})
+	}
+	options.ExporterMetadata["provider"] = "go"
+	options.ExporterMetadata["openfeature"] = true
+
 	goffAPI := controller.NewGoFeatureFlagAPI(controller.GoFeatureFlagApiOptions{
-		Endpoint:   options.Endpoint,
-		HTTPClient: options.HTTPClient,
-		APIKey:     options.APIKey,
+		Endpoint:         options.Endpoint,
+		HTTPClient:       options.HTTPClient,
+		APIKey:           options.APIKey,
+		ExporterMetadata: options.ExporterMetadata,
 	})
 	dataCollectorManager := controller.NewDataCollectorManager(
 		goffAPI,

providers/go-feature-flag/pkg/provider_options.go

@@ -62,6 +62,13 @@ type ProviderOptions struct {
 	// Use -1 if you want to deactivate polling.
 	// default: 120000ms
 	FlagChangePollingInterval time.Duration
+
+	// ExporterMetadata (optional) is the metadata we send to the GO Feature Flag relay proxy when we report the
+	// evaluation data usage.
+	//
+	// ‼️Important: If you are using a GO Feature Flag relay proxy before version v1.41.0, the information of this
+	// field will not be added to your feature events.
+	ExporterMetadata map[string]interface{}
 }
 
 func (o *ProviderOptions) Validation() error {

providers/go-feature-flag/pkg/provider_test.go

@@ -3,8 +3,10 @@ package gofeatureflag_test
 import (
 	"bytes"
 	"context"
+	"encoding/json"
 	"fmt"
 	gofeatureflag "github.com/open-feature/go-sdk-contrib/providers/go-feature-flag/pkg"
+	"github.com/open-feature/go-sdk-contrib/providers/go-feature-flag/pkg/model"
 	of "github.com/open-feature/go-sdk/openfeature"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
@@ -36,11 +38,14 @@ type mockClient struct {
 	callCount           int
 	collectorCallCount  int
 	flagChangeCallCount int
+	collectorRequests   []string
 }
 
 func (m *mockClient) roundTripFunc(req *http.Request) *http.Response {
 	if req.URL.Path == "/v1/data/collector" {
 		m.collectorCallCount++
+		bodyBytes, _ := io.ReadAll(req.Body)
+		m.collectorRequests = append(m.collectorRequests, string(bodyBytes))
 		return &http.Response{
 			StatusCode: http.StatusOK,
 		}
@@ -982,6 +987,7 @@ func TestProvider_DataCollectorHook(t *testing.T) {
 			DisableCache:         false,
 			DataFlushInterval:    100 * time.Millisecond,
 			DisableDataCollector: false,
+			ExporterMetadata:     map[string]interface{}{"toto": 123, "tata": "titi"},
 		}
 		provider, err := gofeatureflag.NewProvider(options)
 		defer provider.Shutdown()
@@ -1003,6 +1009,17 @@ func TestProvider_DataCollectorHook(t *testing.T) {
 		time.Sleep(500 * time.Millisecond)
 		assert.Equal(t, 1, cli.callCount)
 		assert.Equal(t, 1, cli.collectorCallCount)
+
+		// convert cli.collectorRequests[0] to  DataCollectorRequest
+		var dataCollectorRequest model.DataCollectorRequest
+		err = json.Unmarshal([]byte(cli.collectorRequests[0]), &dataCollectorRequest)
+		assert.NoError(t, err)
+		assert.Equal(t, map[string]interface{}{
+			"openfeature": true,
+			"provider":    "go",
+			"tata":        "titi",
+			"toto":        float64(123),
+		}, dataCollectorRequest.Meta)
 	})
 
 	t.Run("DataCollectorHook is called for errors and call API", func(t *testing.T) {