[FSSDK-9862] Add OpenTelemetry Tracing support

examples/benchmark/main.go

@@ -3,16 +3,15 @@
 package main
 
 import (
-	"io/ioutil"
 	"log"
 	"os"
 	"path"
 
+	"github.com/pkg/profile"
+
 	"github.com/optimizely/go-sdk/pkg/client"
 	"github.com/optimizely/go-sdk/pkg/decision"
 	"github.com/optimizely/go-sdk/pkg/entities"
-
-	"github.com/pkg/profile"
 )
 
 func stressTest() {
@@ -23,7 +22,7 @@ func stressTest() {
 
 	var datafileDir = path.Join(os.Getenv("DATAFILES_DIR"), "100_entities.json")
 
-	datafile, err := ioutil.ReadFile(datafileDir)
+	datafile, err := os.ReadFile(datafileDir)
 	if err != nil {
 		log.Print(err)
 	}

go.mod

@@ -8,19 +8,24 @@ require (
 	github.com/json-iterator/go v1.1.12
 	github.com/pkg/errors v0.9.1
 	github.com/pkg/profile v1.7.0
-	github.com/stretchr/testify v1.8.2
+	github.com/stretchr/testify v1.8.4
 	github.com/twmb/murmur3 v1.1.6
+	go.opentelemetry.io/otel v1.21.0
+	go.opentelemetry.io/otel/trace v1.21.0
 	golang.org/x/sync v0.1.0
 )
 
 require (
 	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/felixge/fgprof v0.9.3 // indirect
+	github.com/go-logr/logr v1.3.0 // indirect
+	github.com/go-logr/stdr v1.2.2 // indirect
 	github.com/google/pprof v0.0.0-20211214055906-6f57359322fd // indirect
 	github.com/hashicorp/errwrap v1.1.0 // indirect
 	github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd // indirect
 	github.com/modern-go/reflect2 v1.0.2 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
 	github.com/stretchr/objx v0.5.0 // indirect
+	go.opentelemetry.io/otel/metric v1.21.0 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
 )

go.sum

@@ -6,6 +6,13 @@ github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/felixge/fgprof v0.9.3 h1:VvyZxILNuCiUCSXtPtYmmtGvb65nqXh2QFWc0Wpf2/g=
 github.com/felixge/fgprof v0.9.3/go.mod h1:RdbpDgzqYVh/T9fPELJyV7EYJuHB55UTEULNun8eiPw=
+github.com/go-logr/logr v1.2.2/go.mod h1:jdQByPbusPIv2/zmleS9BjJVeZ6kBagPoEUsqbVz/1A=
+github.com/go-logr/logr v1.3.0 h1:2y3SDp0ZXuc6/cjLSZ+Q3ir+QB9T/iG5yYRXqsagWSY=
+github.com/go-logr/logr v1.3.0/go.mod h1:9T104GzyrTigFIr8wt5mBrctHMim0Nb2HLGrmQ40KvY=
+github.com/go-logr/stdr v1.2.2 h1:hSWxHoqTgW2S2qGc0LTAI563KZ5YKYRhT3MFKZMbjag=
+github.com/go-logr/stdr v1.2.2/go.mod h1:mMo/vtBO5dYbehREoey6XUKy/eSumjCCveDpRre4VKE=
+github.com/google/go-cmp v0.6.0 h1:ofyhxvXcZhMsU5ulbFiLKl/XBFqE1GSq7atu8tAmTRI=
+github.com/google/go-cmp v0.6.0/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
 github.com/google/gofuzz v1.0.0/go.mod h1:dBl0BpW6vV/+mYPU4Po3pmUjxk6FQPldtuIdl/M65Eg=
 github.com/google/pprof v0.0.0-20211214055906-6f57359322fd h1:1FjCyPC+syAzJ5/2S8fqdZK1R22vvA0J7JZKcuOIQ7Y=
 github.com/google/pprof v0.0.0-20211214055906-6f57359322fd/go.mod h1:KgnwoLYCZ8IQu3XUZ8Nc/bM9CCZFOyjUNOSygVozoDg=
@@ -37,10 +44,16 @@ github.com/stretchr/objx v0.5.0/go.mod h1:Yh+to48EsGEfYuaHDzXPcE3xhTkx73EhmCGUpE
 github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=
 github.com/stretchr/testify v1.7.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
 github.com/stretchr/testify v1.8.0/go.mod h1:yNjHg4UonilssWZ8iaSj1OCr/vHnekPRkoO+kdMU+MU=
-github.com/stretchr/testify v1.8.2 h1:+h33VjcLVPDHtOdpUCuF+7gSuG3yGIftsP1YvFihtJ8=
-github.com/stretchr/testify v1.8.2/go.mod h1:w2LPCIKwWwSfY2zedu0+kehJoqGctiVI29o6fzry7u4=
+github.com/stretchr/testify v1.8.4 h1:CcVxjf3Q8PM0mHUKJCdn+eZZtm5yQwehR5yeSVQQcUk=
+github.com/stretchr/testify v1.8.4/go.mod h1:sz/lmYIOXD/1dqDmKjjqLyZ2RngseejIcXlSw2iwfAo=
 github.com/twmb/murmur3 v1.1.6 h1:mqrRot1BRxm+Yct+vavLMou2/iJt0tNVTTC0QoIjaZg=
 github.com/twmb/murmur3 v1.1.6/go.mod h1:Qq/R7NUyOfr65zD+6Q5IHKsJLwP7exErjN6lyyq3OSQ=
+go.opentelemetry.io/otel v1.21.0 h1:hzLeKBZEL7Okw2mGzZ0cc4k/A7Fta0uoPgaJCr8fsFc=
+go.opentelemetry.io/otel v1.21.0/go.mod h1:QZzNPQPm1zLX4gZK4cMi+71eaorMSGT3A4znnUvNNEo=
+go.opentelemetry.io/otel/metric v1.21.0 h1:tlYWfeo+Bocx5kLEloTjbcDwBuELRrIFxwdQ36PlJu4=
+go.opentelemetry.io/otel/metric v1.21.0/go.mod h1:o1p3CA8nNHW8j5yuQLdc1eeqEaPfzug24uvsyIEJRWM=
+go.opentelemetry.io/otel/trace v1.21.0 h1:WD9i5gzvoUPuXIXH24ZNBudiarZDKuekPqi/E8fpfLc=
+go.opentelemetry.io/otel/trace v1.21.0/go.mod h1:LGbsEB0f9LGjN+OZaQQ26sohbOmiMR+BaslueVtS/qQ=
 golang.org/x/sync v0.1.0 h1:wsuoTGHzEhffawBOhz5CYhcrV4IdKZbEyZjBMuTp12o=
 golang.org/x/sync v0.1.0/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sys v0.0.0-20211007075335-d3039528d8ac/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=

pkg/client/client.go

@@ -1,5 +1,5 @@
 /****************************************************************************
- * Copyright 2019-2023, Optimizely, Inc. and contributors                   *
+ * Copyright 2019-2024, Optimizely, Inc. and contributors                   *
  *                                                                          *
  * Licensed under the Apache License, Version 2.0 (the "License");          *
  * you may not use this file except in compliance with the License.         *
@@ -18,13 +18,16 @@
 package client
 
 import (
+	"context"
 	"encoding/json"
 	"errors"
 	"fmt"
 	"reflect"
 	"runtime/debug"
 	"strconv"
 
+	"github.com/hashicorp/go-multierror"
+
 	"github.com/optimizely/go-sdk/pkg/config"
 	"github.com/optimizely/go-sdk/pkg/decide"
 	"github.com/optimizely/go-sdk/pkg/decision"
@@ -37,13 +40,18 @@ import (
 	pkgOdpSegment "github.com/optimizely/go-sdk/pkg/odp/segment"
 	pkgOdpUtils "github.com/optimizely/go-sdk/pkg/odp/utils"
 	"github.com/optimizely/go-sdk/pkg/optimizelyjson"
+	"github.com/optimizely/go-sdk/pkg/tracing"
 	"github.com/optimizely/go-sdk/pkg/utils"
+)
 
-	"github.com/hashicorp/go-multierror"
+const (
+	// DefaultTracerName is the name of the tracer used by the Optimizely SDK
+	DefaultTracerName string = "OptimizelySDK"
 )
 
 // OptimizelyClient is the entry point to the Optimizely SDK
 type OptimizelyClient struct {
+	ctx                  context.Context
 	ConfigManager        config.ProjectConfigManager
 	DecisionService      decision.Service
 	EventProcessor       event.Processor
@@ -52,6 +60,7 @@ type OptimizelyClient struct {
 	execGroup            *utils.ExecGroup
 	logger               logging.OptimizelyLogProducer
 	defaultDecideOptions *decide.Options
+	tracer               tracing.Tracer
 }
 
 // CreateUserContext creates a context of the user for which decision APIs will be called.
@@ -65,6 +74,12 @@ func (o *OptimizelyClient) CreateUserContext(userID string, attributes map[strin
 	return newOptimizelyUserContext(o, userID, attributes, nil, nil)
 }
 
+// WithTraceContext sets the context for the OptimizelyClient which can be used to propagate trace information
+func (o *OptimizelyClient) WithTraceContext(ctx context.Context) *OptimizelyClient {
+	o.ctx = ctx
+	return o
+}
+
 func (o *OptimizelyClient) decide(userContext OptimizelyUserContext, key string, options *decide.Options) OptimizelyDecision {
 	var err error
 	defer func() {
@@ -83,6 +98,9 @@ func (o *OptimizelyClient) decide(userContext OptimizelyUserContext, key string,
 		}
 	}()
 
+	_, span := o.tracer.StartSpan(o.ctx, DefaultTracerName, "decide")
+	defer span.End()
+
 	decisionContext := decision.FeatureDecisionContext{
 		ForcedDecisionService: userContext.forcedDecisionService,
 	}
@@ -188,6 +206,9 @@ func (o *OptimizelyClient) decideForKeys(userContext OptimizelyUserContext, keys
 		}
 	}()
 
+	_, span := o.tracer.StartSpan(o.ctx, DefaultTracerName, "decideForKeys")
+	defer span.End()
+
 	decisionMap := map[string]OptimizelyDecision{}
 	if _, err = o.getProjectConfig(); err != nil {
 		o.logger.Error("Optimizely instance is not valid, failing decideForKeys call.", err)
@@ -228,6 +249,9 @@ func (o *OptimizelyClient) decideAll(userContext OptimizelyUserContext, options
 		}
 	}()
 
+	_, span := o.tracer.StartSpan(o.ctx, DefaultTracerName, "decideForKeys")
+	defer span.End()
+
 	projectConfig, err := o.getProjectConfig()
 	if err != nil {
 		o.logger.Error("Optimizely instance is not valid, failing decideAll call.", err)
@@ -261,6 +285,9 @@ func (o *OptimizelyClient) fetchQualifiedSegments(userContext *OptimizelyUserCon
 		}
 	}()
 
+	_, span := o.tracer.StartSpan(o.ctx, DefaultTracerName, "fetchQualifiedSegments")
+	defer span.End()
+
 	// on failure, qualifiedSegments should be reset if a previous value exists.
 	userContext.SetQualifiedSegments(nil)
 
@@ -305,6 +332,9 @@ func (o *OptimizelyClient) SendOdpEvent(eventType, action string, identifiers ma
 		}
 	}()
 
+	_, span := o.tracer.StartSpan(o.ctx, DefaultTracerName, "SendOdpEvent")
+	defer span.End()
+
 	if _, err = o.getProjectConfig(); err != nil {
 		o.logger.Error("SendOdpEvent failed with error:", decide.GetDecideError(decide.SDKNotReady))
 		return err
@@ -344,6 +374,9 @@ func (o *OptimizelyClient) Activate(experimentKey string, userContext entities.U
 		}
 	}()
 
+	_, span := o.tracer.StartSpan(o.ctx, DefaultTracerName, "Activate")
+	defer span.End()
+
 	decisionContext, experimentDecision, err := o.getExperimentDecision(experimentKey, userContext)
 	if err != nil {
 		o.logger.Error("received an error while computing experiment decision", err)
@@ -382,6 +415,9 @@ func (o *OptimizelyClient) IsFeatureEnabled(featureKey string, userContext entit
 		}
 	}()
 
+	_, span := o.tracer.StartSpan(o.ctx, DefaultTracerName, "IsFeatureEnabled")
+	defer span.End()
+
 	decisionContext, featureDecision, err := o.getFeatureDecision(featureKey, "", userContext)
 	if err != nil {
 		o.logger.Error("received an error while computing feature decision", err)
@@ -436,6 +472,9 @@ func (o *OptimizelyClient) GetEnabledFeatures(userContext entities.UserContext)
 		}
 	}()
 
+	_, span := o.tracer.StartSpan(o.ctx, DefaultTracerName, "GetEnabledFeatures")
+	defer span.End()
+
 	projectConfig, err := o.getProjectConfig()
 	if err != nil {
 		o.logger.Error("Error retrieving ProjectConfig", err)
@@ -453,6 +492,8 @@ func (o *OptimizelyClient) GetEnabledFeatures(userContext entities.UserContext)
 
 // GetFeatureVariableBoolean returns the feature variable value of type bool associated with the given feature and variable keys.
 func (o *OptimizelyClient) GetFeatureVariableBoolean(featureKey, variableKey string, userContext entities.UserContext) (convertedValue bool, err error) {
+	_, span := o.tracer.StartSpan(o.ctx, DefaultTracerName, "GetFeatureVariableBoolean")
+	defer span.End()
 
 	stringValue, variableType, featureDecision, err := o.getFeatureVariable(featureKey, variableKey, userContext)
 	defer func() {
@@ -486,6 +527,8 @@ func (o *OptimizelyClient) GetFeatureVariableBoolean(featureKey, variableKey str
 
 // GetFeatureVariableDouble returns the feature variable value of type double associated with the given feature and variable keys.
 func (o *OptimizelyClient) GetFeatureVariableDouble(featureKey, variableKey string, userContext entities.UserContext) (convertedValue float64, err error) {
+	_, span := o.tracer.StartSpan(o.ctx, DefaultTracerName, "GetFeatureVariableDouble")
+	defer span.End()
 
 	stringValue, variableType, featureDecision, err := o.getFeatureVariable(featureKey, variableKey, userContext)
 	defer func() {
@@ -519,6 +562,8 @@ func (o *OptimizelyClient) GetFeatureVariableDouble(featureKey, variableKey stri
 
 // GetFeatureVariableInteger returns the feature variable value of type int associated with the given feature and variable keys.
 func (o *OptimizelyClient) GetFeatureVariableInteger(featureKey, variableKey string, userContext entities.UserContext) (convertedValue int, err error) {
+	_, span := o.tracer.StartSpan(o.ctx, DefaultTracerName, "GetFeatureVariableInteger")
+	defer span.End()
 
 	stringValue, variableType, featureDecision, err := o.getFeatureVariable(featureKey, variableKey, userContext)
 	defer func() {
@@ -552,6 +597,8 @@ func (o *OptimizelyClient) GetFeatureVariableInteger(featureKey, variableKey str
 
 // GetFeatureVariableString returns the feature variable value of type string associated with the given feature and variable keys.
 func (o *OptimizelyClient) GetFeatureVariableString(featureKey, variableKey string, userContext entities.UserContext) (stringValue string, err error) {
+	_, span := o.tracer.StartSpan(o.ctx, DefaultTracerName, "GetFeatureVariableString")
+	defer span.End()
 
 	stringValue, variableType, featureDecision, err := o.getFeatureVariable(featureKey, variableKey, userContext)
 
@@ -583,6 +630,8 @@ func (o *OptimizelyClient) GetFeatureVariableString(featureKey, variableKey stri
 
 // GetFeatureVariableJSON returns the feature variable value of type json associated with the given feature and variable keys.
 func (o *OptimizelyClient) GetFeatureVariableJSON(featureKey, variableKey string, userContext entities.UserContext) (optlyJSON *optimizelyjson.OptimizelyJSON, err error) {
+	_, span := o.tracer.StartSpan(o.ctx, DefaultTracerName, "GetFeatureVariableJSON")
+	defer span.End()
 
 	stringVal, variableType, featureDecision, err := o.getFeatureVariable(featureKey, variableKey, userContext)
 	defer func() {
@@ -620,6 +669,8 @@ func (o *OptimizelyClient) GetFeatureVariableJSON(featureKey, variableKey string
 
 // getFeatureVariable is a helper function, returns feature variable as a string along with it's associated type and feature decision
 func (o *OptimizelyClient) getFeatureVariable(featureKey, variableKey string, userContext entities.UserContext) (string, entities.VariableType, *decision.FeatureDecision, error) {
+	_, span := o.tracer.StartSpan(o.ctx, DefaultTracerName, "getFeatureVariable")
+	defer span.End()
 
 	featureDecisionContext, featureDecision, err := o.getFeatureDecision(featureKey, variableKey, userContext)
 	if err != nil {
@@ -639,6 +690,8 @@ func (o *OptimizelyClient) getFeatureVariable(featureKey, variableKey string, us
 
 // GetFeatureVariable returns feature variable as a string along with it's associated type.
 func (o *OptimizelyClient) GetFeatureVariable(featureKey, variableKey string, userContext entities.UserContext) (string, entities.VariableType, error) {
+	_, span := o.tracer.StartSpan(o.ctx, DefaultTracerName, "GetFeatureVariable")
+	defer span.End()
 
 	stringValue, variableType, featureDecision, err := o.getFeatureVariable(featureKey, variableKey, userContext)
 
@@ -680,6 +733,8 @@ func (o *OptimizelyClient) GetFeatureVariable(featureKey, variableKey string, us
 
 // GetAllFeatureVariablesWithDecision returns all the variables for a given feature along with the enabled state.
 func (o *OptimizelyClient) GetAllFeatureVariablesWithDecision(featureKey string, userContext entities.UserContext) (enabled bool, variableMap map[string]interface{}, err error) {
+	_, span := o.tracer.StartSpan(o.ctx, DefaultTracerName, "GetAllFeatureVariablesWithDecision")
+	defer span.End()
 
 	variableMap = make(map[string]interface{})
 	decisionContext, featureDecision, err := o.getFeatureDecision(featureKey, "", userContext)
@@ -730,6 +785,8 @@ func (o *OptimizelyClient) GetAllFeatureVariablesWithDecision(featureKey string,
 // for a given feature along with the experiment key, variation key and the enabled state.
 // Usage of this method is unsafe and not recommended since it can be removed in any of the next releases.
 func (o *OptimizelyClient) GetDetailedFeatureDecisionUnsafe(featureKey string, userContext entities.UserContext, disableTracking bool) (decisionInfo decision.UnsafeFeatureDecisionInfo, err error) {
+	_, span := o.tracer.StartSpan(o.ctx, DefaultTracerName, "GetDetailedFeatureDecisionUnsafe")
+	defer span.End()
 
 	decisionInfo = decision.UnsafeFeatureDecisionInfo{}
 	decisionInfo.VariableMap = make(map[string]interface{})
@@ -797,6 +854,9 @@ func (o *OptimizelyClient) GetDetailedFeatureDecisionUnsafe(featureKey string, u
 
 // GetAllFeatureVariables returns all the variables as OptimizelyJSON object for a given feature.
 func (o *OptimizelyClient) GetAllFeatureVariables(featureKey string, userContext entities.UserContext) (optlyJSON *optimizelyjson.OptimizelyJSON, err error) {
+	_, span := o.tracer.StartSpan(o.ctx, DefaultTracerName, "GetAllFeatureVariables")
+	defer span.End()
+
 	_, variableMap, err := o.GetAllFeatureVariablesWithDecision(featureKey, userContext)
 	if err != nil {
 		return optlyJSON, err
@@ -824,6 +884,9 @@ func (o *OptimizelyClient) GetVariation(experimentKey string, userContext entiti
 		}
 	}()
 
+	_, span := o.tracer.StartSpan(o.ctx, DefaultTracerName, "GetVariation")
+	defer span.End()
+
 	_, experimentDecision, err := o.getExperimentDecision(experimentKey, userContext)
 	if err != nil {
 		o.logger.Error("received an error while computing experiment decision", err)
@@ -856,6 +919,9 @@ func (o *OptimizelyClient) Track(eventKey string, userContext entities.UserConte
 		}
 	}()
 
+	_, span := o.tracer.StartSpan(o.ctx, DefaultTracerName, "Track")
+	defer span.End()
+
 	projectConfig, e := o.getProjectConfig()
 	if e != nil {
 		o.logger.Error("Optimizely SDK tracking error", e)
@@ -899,6 +965,9 @@ func (o *OptimizelyClient) getFeatureDecision(featureKey, variableKey string, us
 		}
 	}()
 
+	_, span := o.tracer.StartSpan(o.ctx, DefaultTracerName, "getFeatureDecision")
+	defer span.End()
+
 	userID := userContext.ID
 	o.logger.Debug(fmt.Sprintf(`Evaluating feature %q for user %q.`, featureKey, userID))
 
@@ -937,6 +1006,8 @@ func (o *OptimizelyClient) getFeatureDecision(featureKey, variableKey string, us
 }
 
 func (o *OptimizelyClient) getExperimentDecision(experimentKey string, userContext entities.UserContext) (decisionContext decision.ExperimentDecisionContext, experimentDecision decision.ExperimentDecision, err error) {
+	_, span := o.tracer.StartSpan(o.ctx, DefaultTracerName, "getExperimentDecision")
+	defer span.End()
 
 	userID := userContext.ID
 	o.logger.Debug(fmt.Sprintf(`Evaluating experiment %q for user %q.`, experimentKey, userID))
@@ -1033,6 +1104,8 @@ func (o *OptimizelyClient) getTypedValue(value string, variableType entities.Var
 }
 
 func (o *OptimizelyClient) getProjectConfig() (projectConfig config.ProjectConfig, err error) {
+	_, span := o.tracer.StartSpan(o.ctx, DefaultTracerName, "getProjectConfig")
+	defer span.End()
 
 	if isNil(o.ConfigManager) {
 		return nil, errors.New("project config manager is not initialized")
@@ -1057,7 +1130,8 @@ func (o *OptimizelyClient) getAllOptions(options *decide.Options) decide.Options
 
 // GetOptimizelyConfig returns OptimizelyConfig object
 func (o *OptimizelyClient) GetOptimizelyConfig() (optimizelyConfig *config.OptimizelyConfig) {
-
+	_, span := o.tracer.StartSpan(o.ctx, DefaultTracerName, "GetOptimizelyConfig")
+	defer span.End()
 	return o.ConfigManager.GetOptimizelyConfig()
 }
 
@@ -1072,6 +1146,9 @@ func (o *OptimizelyClient) Close() {
 }
 
 func (o *OptimizelyClient) getDecisionVariableMap(feature entities.Feature, variation *entities.Variation, featureEnabled bool) (map[string]interface{}, decide.DecisionReasons) {
+	_, span := o.tracer.StartSpan(o.ctx, DefaultTracerName, "getDecisionVariableMap")
+	defer span.End()
+
 	reasons := decide.NewDecisionReasons(nil)
 	valuesMap := map[string]interface{}{}