feat: redact SDKKey in logs

Author: antoinedeschenes

options.go

@@ -3,8 +3,6 @@ package sdk_proxy
 import (
 	"encoding/json"
 	"fmt"
-	"github.com/devcyclehq/go-server-sdk/v2/api"
-	"github.com/launchdarkly/eventsource"
 	"io"
 	"log"
 	"net/http"
@@ -13,8 +11,10 @@ import (
 	"time"
 
 	devcycle "github.com/devcyclehq/go-server-sdk/v2"
+	"github.com/devcyclehq/go-server-sdk/v2/api"
 	"github.com/gin-gonic/gin"
 	"github.com/kelseyhightower/envconfig"
+	"github.com/launchdarkly/eventsource"
 )
 
 const (
@@ -147,6 +147,14 @@ func (i *ProxyInstance) Default() {
 		}
 	}
 }
+
+func (i ProxyInstance) String() string {
+	// Use a value receiver to override the SDKKey for logging
+	type alias ProxyInstance
+	i.SDKKey = "***REDACTED***"
+	return fmt.Sprintf("%+v", (alias)(i))
+}
+
 func (c *ProxyConfig) Default() {
 	for i := range c.Instances {
 		c.Instances[i].Default()

options_test.go

@@ -1,7 +1,9 @@
 package sdk_proxy
 
 import (
+	"fmt"
 	"os"
+	"strings"
 	"testing"
 	"time"
 
@@ -212,3 +214,29 @@ func TestParseConfig(t *testing.T) {
 		})
 	}
 }
+
+func TestProxyInstanceStringer(t *testing.T) {
+	// Create a test instance with a SDK key
+	instance := ProxyInstance{
+		SDKKey: "dvc_server_test_key_12345",
+	}
+
+	// Test the fmt.Stringer implementation
+	// using fmt.Sprintf to invoke the String() method
+	result := fmt.Sprintf("%+v", instance)
+
+	// Verify that the SDK key is redacted
+	if strings.Contains(result, "SDKKey:dvc_server_test_key_12345") {
+		t.Error("String() method should redact the SDK key, but it was found in the output")
+	}
+
+	// Verify that the redacted text is present
+	if !strings.Contains(result, "SDKKey:***REDACTED***") {
+		t.Error("String() method should contain '***REDACTED***' for the SDK key")
+	}
+
+	// Verify that the original instance's SDK key is not modified
+	if instance.SDKKey != "dvc_server_test_key_12345" {
+		t.Error("Original instance's SDK key should not be modified by String() method")
+	}
+}