feat: logging support via slog

README.md

@@ -1,11 +1,6 @@
-# Confidence OpenFeature Go Provider
+# Confidence Go SDK
 
-This repo contains the OpenFeature Go flag provider for [Confidence](https://confidence.spotify.com/).
-
-## OpenFeature
-
-Before starting to use the provider, it can be helpful to read through the general [OpenFeature docs](https://docs.openfeature.dev/)
-and get familiar with the concepts. 
+This repo contains the [Confidence](https://confidence.spotify.com/) Go SDK.
 
 ## Adding the dependency
 <!---x-release-please-start-version-->
@@ -15,6 +10,74 @@ require (
 )
 ```
 <!---x-release-please-end-->
+
+## Creating and using the SDK
+
+Below is an example for how to create an instance of the Confidence SDK, and then resolve a flag with a boolean attribute.
+
+The SDK is configured via `SetAPIConfig(...)` and `*c.NewAPIConfig(...)`, with which you can set the api key for authentication.
+Optionally, a custom resolve API url can be configured if, for example, the resolver service is running on a locally deployed side-car (`NewAPIConfigWithUrl(...)`).
+
+
+You can retrieve properties on the flag variant using property dot notation, meaning `test-flag.boolean-key` will retrieve the attribute `boolean-key` on the flag `test-flag`. 
+
+You can also use only the flag name `test-flag` and retrieve all values as a map with `GetObjectFlag()`. 
+
+The flag's schema is validated against the requested data type, and if it doesn't match it will fall back to the default value. 
+
+```go
+import (
+    c "github.com/spotify/confidence-sdk-go/pkg/confidence"
+)
+
+confidenceSdk := c.NewConfidenceBuilder().SetAPIConfig(*c.NewAPIConfig("clientSecret")).Build()
+
+confidence.PutContext("targeting_key", "Random_targeting_key")
+flagValue := confidence.GetBoolFlag(context.Background(), "test-flag.boolean-key", false).Value
+// we can also pull flag values using a Confidence instance with extra context
+confidence.WithContext(map[string]interface{}{
+    "Something": 343,
+}).GetBoolFlag(context.Background(), "test-flag.boolean-key", false).Value
+```
+
+The flag will be applied immediately, meaning that Confidence will count the targeted user as having received the treatment once they have have been evaluated. 
+
+### Tracking
+
+Confidence support event tracking through the SDK. The `Track()` function accepts an en event name and a map of arbitrary data connected to the event.
+The current context will also be appended to the event data.
+
+```go
+wg := confidence.Track(context.Background(), "checkout-complete", map[string]interface{}{
+    "orderId": 1234,
+    "total":   100.0,
+    "items":   []string{"item1", "item2"},
+})
+wg.Wait()
+```
+
+## Logging
+
+Unless specifically configured using the `ConfidenceBuilder` `setLogger()` function; Confidence uses the default instance of [slog](https://pkg.go.dev/log/slog) for logging valuable information during runtime.
+When getting started with Confidence, we suggest you configure [slog](https://pkg.go.dev/log/slog) to emit debug level information:
+```go
+// Set up the logger with the debug log level
+var programLevel = new(slog.LevelVar)
+programLevel.Set(slog.LevelDebug)
+h := slog.NewJSONHandler(os.Stdout, &slog.HandlerOptions{Level: programLevel})
+slog.SetDefault(slog.New(h))
+``` 
+
+## Demo app
+
+To run the demo app, replace the `CLIENT_SECRET` with client secret setup in the 
+[Confidence](https://confidence.spotify.com/) console, the flags with existing flags and execute 
+the app with `cd demo && go run GoDemoApp.go`.
+
+## Confidence OpenFeature Go Provider
+
+The SDK can be combined with the [OpenFeature Go SDK](https://github.com/open-feature/go-sdk), the repo also contains an OpenFeature Provider. Before starting to use the provider, it can be helpful to read through the general [OpenFeature docs](https://docs.openfeature.dev/)
+and get familiar with the concepts. 
 It's also important to add the underlying OpenFeature SDK dependency:
 ```
 require (
@@ -27,10 +90,8 @@ require (
 Below is an example for how to create a OpenFeature client using the Confidence flag provider, and then resolve
 a flag with a boolean attribute.
 
-The provider is configured via `NewAPIConfig(...)`, with which you can set the api key for authentication.
-Optionally, a custom resolve API url can be configured if, for example, the resolver service is running on a locally deployed side-car (`NewAPIConfigWithUrl(...)`).
-
-The flag will be applied immediately, meaning that Confidence will count the targeted user as having received the treatment. 
+The Provider constructor accepts a confidence instance: `NewFlagProvider(confidenceSdk)`, please refer to the previous sections 
+of this readme for more detailed information on how to set that up.
 
 You can retrieve attributes on the flag variant using property dot notation, meaning `test-flag.boolean-key` will retrieve
 the attribute `boolean-key` on the flag `test-flag`. 
@@ -46,7 +107,7 @@ import (
     p "github.com/spotify/confidence-sdk-go/pkg/provider"
 )
 
-confidenceSdk := c.NewConfidenceBuilder().SetAPIConfig(c.APIConfig{APIKey: "clientSecret"}).Build()
+confidenceSdk := c.NewConfidenceBuilder().SetAPIConfig(*c.NewAPIConfig("clientSecret")).Build()
 confidenceProvider := p.NewFlagProvider(confidenceSdk)
 
 
@@ -61,8 +122,4 @@ attributes["user_id"] = "user1"
 boolValue, error := client.BooleanValue(context.Background(), "test-flag.boolean-key", false, 
 	o.NewEvaluationContext("", attributes))
 ```
-## Demo app
 
-To run the demo app, replace the `CLIENT_SECRET` with client secret setup in the 
-[Confidence](https://confidence.spotify.com/) console, the flags with existing flags and execute 
-the app with `cd demo && go run GoDemoApp.go`.

demo/GoDemoApp.go

@@ -3,22 +3,35 @@ package main
 import (
 	"context"
 	"fmt"
+	"log/slog"
+	"os"
+
 	c "github.com/spotify/confidence-sdk-go/pkg/confidence"
 )
 
 func main() {
-	fmt.Println("Fetching the flags...")
 
-	confidence := c.NewConfidenceBuilder().SetAPIConfig(*c.NewAPIConfig("API_KEY")).Build()
-	targetingKey := "Random_targeting_key"
-	confidence.PutContext("targeting_key", targetingKey)
+	// Set up the logger with the debug log level
+	var programLevel = new(slog.LevelVar)
+	programLevel.Set(slog.LevelDebug)
+	h := slog.NewJSONHandler(os.Stdout, &slog.HandlerOptions{Level: programLevel})
+	slog.SetDefault(slog.New(h))
 
-	colorValue := confidence.GetStringFlag(context.Background(), "hawkflag.color", "defaultValue").Value
-	messageValue := confidence.GetStringFlag(context.Background(), "hawkflag.message", "defaultValue").Value
+	confidence := c.NewConfidenceBuilder().SetAPIConfig(*c.NewAPIConfig("CLIENT_SECRET")).Build()
+	confidence.PutContext("targeting_key", "Random_targeting_key")
+	withAddedContext := confidence.WithContext(map[string]interface{}{
+		"Something": 343,
+	})
+
+	// we can pull flag values using a Confidence instance with extra context
+	fmt.Println("Fetching the flags...")
+	colorValue := withAddedContext.GetStringFlag(context.Background(), "hawkflag.color", "defaultValue").Value
+	messageValue := withAddedContext.GetStringFlag(context.Background(), "hawkflag.message", "defaultValue").Value
 
 	colorYellow := "\033[33m"
 	colorGreen := "\033[32m"
 	colorRed := "\033[31m"
+	colorDefault := "\033[0m"
 
 	fmt.Println(" Color --> " + colorValue)
 
@@ -30,8 +43,13 @@ func main() {
 	default:
 		fmt.Println(colorRed, "Message --> "+messageValue)
 	}
+	fmt.Print(colorDefault, "")
 
-	wg := confidence.Track(context.Background(), "page-viewed", map[string]interface{}{})
+	wg := confidence.Track(context.Background(), "checkout-complete", map[string]interface{}{
+		"orderId": 1234,
+		"total":   100.0,
+		"items":   []string{"item1", "item2"},
+	})
 	wg.Wait()
 	fmt.Println("Event sent")
 }

demo/go.mod

@@ -4,4 +4,6 @@ go 1.22.2
 
 require github.com/spotify/confidence-sdk-go v0.2.3
 
-replace github.com/spotify/confidence-sdk-go => ../
+require golang.org/x/exp v0.0.0-20240213143201-ec583247a57a // indirect
+
+replace github.com/spotify/confidence-sdk-go => ../

demo/go.sum

@@ -1,15 +1,10 @@
 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/go-logr/logr v1.4.1/go.mod h1:9T104GzyrTigFIr8wt5mBrctHMim0Nb2HLGrmQ40KvY=
-github.com/open-feature/go-sdk v1.10.0/go.mod h1:+rkJhLBtYsJ5PZNddAgFILhRAAxwrJ32aU7UEUm4zQI=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
-github.com/spotify/confidence-sdk-go v0.2.2-0.20240523155258-4bbc177010cc h1:CyQdom204c6w4UjbT63Otk3axZff4mEbeVDF/snvfas=
-github.com/spotify/confidence-sdk-go v0.2.2-0.20240523155258-4bbc177010cc/go.mod h1:TYBqx3F0AZO7HZF8Nkf2dWnvVHH91ICo0W6e9wmLsk4=
-github.com/spotify/confidence-sdk-go v0.2.3 h1:vJJjWJo6qgpgX+Lg/uiWrtzRw+qaJhwIQRkxwrBJUCA=
-github.com/spotify/confidence-sdk-go v0.2.3/go.mod h1:3MInYY3UiHaNToPlL0mTgbWjcwMMGV/4OfbWAiJ2JC0=
 github.com/stretchr/testify v1.9.0 h1:HtqpIVDClZ4nwg75+f6Lvsy/wHu+3BoSGCbBAcpTsTg=
 github.com/stretchr/testify v1.9.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY=
+golang.org/x/exp v0.0.0-20240213143201-ec583247a57a h1:HinSgX1tJRX3KsL//Gxynpw5CTOAIPhgL4W8PNiIpVE=
 golang.org/x/exp v0.0.0-20240213143201-ec583247a57a/go.mod h1:CxmFvTBINI24O/j8iY7H1xHzx2i4OsyguNBmN/uPtqc=
 gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
 gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

go.mod

@@ -5,13 +5,12 @@ go 1.19
 require (
 	github.com/open-feature/go-sdk v1.10.0
 	github.com/stretchr/testify v1.9.0
-	golang.org/x/text v0.14.0
+	golang.org/x/exp v0.0.0-20240213143201-ec583247a57a
 )
 
 require (
 	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/go-logr/logr v1.4.1 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
-	golang.org/x/exp v0.0.0-20240213143201-ec583247a57a // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
 )

go.sum

@@ -12,7 +12,6 @@ github.com/stretchr/testify v1.9.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8
 golang.org/x/exp v0.0.0-20240213143201-ec583247a57a h1:HinSgX1tJRX3KsL//Gxynpw5CTOAIPhgL4W8PNiIpVE=
 golang.org/x/exp v0.0.0-20240213143201-ec583247a57a/go.mod h1:CxmFvTBINI24O/j8iY7H1xHzx2i4OsyguNBmN/uPtqc=
 golang.org/x/text v0.14.0 h1:ScX5w1eTa3QqT8oi6+ziP7dTV1S2+ALU0bI+0zXKWiQ=
-golang.org/x/text v0.14.0/go.mod h1:18ZOQIKpY8NJVqYksKHtTdi31H5itFRjB5/qKTNYzSU=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=

pkg/confidence/EventUploader.go

@@ -5,6 +5,8 @@ import (
 	"context"
 	"encoding/json"
 	"net/http"
+
+	"golang.org/x/exp/slog"
 )
 
 type EventUploader interface {
@@ -14,6 +16,7 @@ type EventUploader interface {
 type HttpEventUploader struct {
 	Client *http.Client
 	Config APIConfig
+	Logger *slog.Logger
 }
 
 func (e HttpEventUploader) upload(ctx context.Context, request EventBatchRequest) {
@@ -31,7 +34,11 @@ func (e HttpEventUploader) upload(ctx context.Context, request EventBatchRequest
 
 	resp, err := e.Client.Do(req)
 	if err != nil {
+		e.Logger.Warn("Failed to perform upload request", "error", err)
 		return
 	}
+	if resp.StatusCode != http.StatusOK {
+		e.Logger.Warn("Failed to upload event", "status", resp.Status)
+	}
 	defer resp.Body.Close()
 }

pkg/confidence/confidence.go

@@ -2,12 +2,16 @@ package confidence
 
 import (
 	"context"
+	"encoding/json"
 	"fmt"
 	"net/http"
+	"net/url"
 	"reflect"
 	"strings"
 	"sync"
 	"time"
+
+	"golang.org/x/exp/slog"
 )
 
 type FlagResolver interface {
@@ -30,6 +34,7 @@ type Confidence struct {
 	contextMap    map[string]interface{}
 	Config        APIConfig
 	ResolveClient ResolveClient
+	Logger        *slog.Logger
 }
 
 func (e Confidence) GetContext() map[string]interface{} {
@@ -55,6 +60,11 @@ type ConfidenceBuilder struct {
 	confidence Confidence
 }
 
+func (e ConfidenceBuilder) SetLogger(logger *slog.Logger) ConfidenceBuilder {
+	e.confidence.Logger = logger
+	return e
+}
+
 func (e ConfidenceBuilder) SetAPIConfig(config APIConfig) ConfidenceBuilder {
 	e.confidence.Config = config
 	if config.APIResolveBaseUrl == "" {
@@ -69,14 +79,18 @@ func (e ConfidenceBuilder) SetResolveClient(client ResolveClient) ConfidenceBuil
 }
 
 func (e ConfidenceBuilder) Build() Confidence {
+	if e.confidence.Logger == nil {
+		e.confidence.Logger = slog.Default()
+	}
 	if e.confidence.ResolveClient == nil {
 		e.confidence.ResolveClient = HttpResolveClient{Client: &http.Client{}, Config: e.confidence.Config}
 	}
 	if e.confidence.EventUploader == nil {
-		e.confidence.EventUploader = HttpEventUploader{Client: &http.Client{}, Config: e.confidence.Config}
+		e.confidence.EventUploader = HttpEventUploader{Client: &http.Client{}, Config: e.confidence.Config, Logger: e.confidence.Logger}
 	}
 
 	e.confidence.contextMap = make(map[string]interface{})
+	e.confidence.Logger.Info("Confidence created", "config", e.confidence.Config)
 	return e.confidence
 }
 
@@ -117,8 +131,10 @@ func (e Confidence) Track(ctx context.Context, eventName string, data map[string
 			SendTime:      iso8601Time,
 			Events:        []Event{event},
 		}
+		e.Logger.Debug("EventUploading started", "eventName", eventName)
 		e.EventUploader.upload(ctx, batch)
 		wg.Done()
+		e.Logger.Debug("EventUploading completed", "eventName", eventName)
 	}()
 	return &wg
 }
@@ -138,6 +154,7 @@ func (e Confidence) WithContext(context map[string]interface{}) Confidence {
 		contextMap:    newMap,
 		Config:        e.Config,
 		ResolveClient: e.ResolveClient,
+		Logger:        e.Logger,
 	}
 }
 
@@ -196,9 +213,18 @@ func (e Confidence) ResolveFlag(ctx context.Context, flag string, defaultValue i
 			Sdk: sdk{Id: SDK_ID, Version: SDK_VERSION}})
 
 	if err != nil {
+		slog.Warn("Error in resolving flag", "flag", flag, "error", err)
 		return processResolveError(err, defaultValue)
 	}
+	key := url.QueryEscape(e.Config.APIKey)
+	flagEncoded := url.QueryEscape(flag)
+	json, err := json.Marshal(e.GetContext())
+	if err == nil {
+		jsonContextEncoded := url.QueryEscape(string(json))
+		e.Logger.Debug("See resolves for " + flag + " in Confidence: https://app.confidence.spotify.com/flags/resolver-test?client-key=" + key + "&flag=flags/" + flagEncoded + "&context=" + jsonContextEncoded)
+	}
 	if len(resp.ResolvedFlags) == 0 {
+		slog.Debug("Flag not found", "flag", flag)
 		return InterfaceResolutionDetail{
 			Value: defaultValue,
 			ResolutionDetail: ResolutionDetail{
@@ -213,6 +239,7 @@ func (e Confidence) ResolveFlag(ctx context.Context, flag string, defaultValue i
 
 	resolvedFlag := resp.ResolvedFlags[0]
 	if resolvedFlag.Flag != requestFlagName {
+		slog.Warn("Unexpected flag from remote", "flag", resolvedFlag.Flag)
 		return InterfaceResolutionDetail{
 			Value: defaultValue,
 			ResolutionDetail: ResolutionDetail{

pkg/confidence/confidence_context_test.go

@@ -5,6 +5,8 @@ import (
 	"reflect"
 	"testing"
 
+	"golang.org/x/exp/slog"
+
 	"github.com/stretchr/testify/assert"
 )
 
@@ -102,6 +104,7 @@ func create_confidence(t *testing.T, response ResolveResponse) *Confidence {
 		Config:        config,
 		ResolveClient: MockResolveClient{MockedResponse: response, MockedError: nil, TestingT: t},
 		contextMap:    make(map[string]interface{}),
+		Logger:        slog.Default(),
 	}
 }
 
@@ -114,5 +117,6 @@ func createConfidenceWithUploader(t *testing.T, response ResolveResponse, upload
 		EventUploader: uploader,
 		ResolveClient: MockResolveClient{MockedResponse: response, MockedError: nil, TestingT: t},
 		contextMap:    make(map[string]interface{}),
+		Logger:        slog.Default(),
 	}
 }