feat: custom tracing keys

README.md

@@ -69,6 +69,41 @@ No breaking changes will be made to exported APIs before v2.0.0.
 
 ## 💡 Usage
 
+### Handler options
+
+```go
+type Config struct {
+	DefaultLevel     slog.Level
+	ClientErrorLevel slog.Level
+	ServerErrorLevel slog.Level
+
+	WithUserAgent      bool
+	WithRequestID      bool
+	WithRequestBody    bool
+	WithRequestHeader  bool
+	WithResponseBody   bool
+	WithResponseHeader bool
+	WithSpanID         bool
+	WithTraceID        bool
+
+	Filters []Filter
+}
+```
+
+Attributes will be injected in log payload.
+
+Other global parameters:
+
+```go
+slogfiber.TraceIDKey = "trace-id"
+slogfiber.SpanIDKey = "span-id"
+slogfiber.RequestBodyMaxSize  = 64 * 1024 // 64KB
+slogfiber.ResponseBodyMaxSize = 64 * 1024 // 64KB
+slogfiber.HiddenRequestHeaders = map[string]struct{}{ ... }
+slogfiber.HiddenResponseHeaders = map[string]struct{}{ ... }
+slogfiber.RequestIDHeaderKey = "X-Request-Id"
+```
+
 ### Minimal
 
 ```go

go.mod

@@ -12,6 +12,7 @@ require (
 	github.com/mattn/go-runewidth v0.0.15 // indirect
 	github.com/rivo/uniseg v0.2.0 // indirect
 	github.com/samber/lo v1.38.1 // indirect
+	github.com/samber/slog-formatter v1.0.0
 	github.com/samber/slog-multi v1.0.0 // indirect
 	github.com/valyala/bytebufferpool v1.0.0 // indirect
 	github.com/valyala/fasthttp v1.51.0 // indirect
@@ -23,7 +24,6 @@ require (
 require (
 	github.com/gofiber/fiber/v2 v2.52.1
 	github.com/google/uuid v1.5.0
-	github.com/samber/slog-formatter v1.0.0
 	go.opentelemetry.io/otel/trace v1.19.0
 	go.uber.org/goleak v1.2.1
 )

middleware.go

@@ -18,6 +18,9 @@ type customAttributesCtxKeyType struct{}
 var customAttributesCtxKey = customAttributesCtxKeyType{}
 
 var (
+	TraceIDKey = "trace-id"
+	SpanIDKey  = "span-id"
+
 	RequestBodyMaxSize  = 64 * 1024 // 64KB
 	ResponseBodyMaxSize = 64 * 1024 // 64KB
 
@@ -175,11 +178,11 @@ func NewWithConfig(logger *slog.Logger, config Config) fiber.Handler {
 		// otel
 		if config.WithTraceID {
 			traceID := trace.SpanFromContext(c.Context()).SpanContext().TraceID().String()
-			baseAttributes = append(baseAttributes, slog.String("trace-id", traceID))
+			baseAttributes = append(baseAttributes, slog.String(TraceIDKey, traceID))
 		}
 		if config.WithSpanID {
 			spanID := trace.SpanFromContext(c.Context()).SpanContext().SpanID().String()
-			baseAttributes = append(baseAttributes, slog.String("span-id", spanID))
+			baseAttributes = append(baseAttributes, slog.String(SpanIDKey, spanID))
 		}
 
 		// request body