feat: extract request id provider

example/roundtripwares/requestid/main.go

@@ -53,8 +53,11 @@ func main() {
 
 	svr.AddService(
 		keel.NewServiceHTTP(l, "demo", "localhost:8080", svs,
+			// add middleware
 			middleware.RequestID(),
+			// add middleware
 			middleware.SessionID(),
+			// add middleware
 			middleware.TrackingID(),
 		),
 	)

net/http/middleware/requestid.go

@@ -3,34 +3,28 @@ package middleware
 import (
 	"net/http"
 
-	"github.com/google/uuid"
 	"go.uber.org/zap"
 
 	keelhttpcontext "github.com/foomo/keel/net/http/context"
+	"github.com/foomo/keel/net/http/provider"
 )
 
 type (
 	RequestIDOptions struct {
-		Generator         RequestIDGenerator
+		Provider          provider.RequestID
 		RequestHeader     []string
 		ResponseHeader    string
 		SetRequestHeader  bool
 		SetResponseHeader bool
 		SetContext        bool
 	}
-	RequestIDOption    func(*RequestIDOptions)
-	RequestIDGenerator func() string
+	RequestIDOption func(*RequestIDOptions)
 )
 
-// DefaultRequestIDGenerator function
-func DefaultRequestIDGenerator() string {
-	return uuid.New().String()
-}
-
 // GetDefaultRequestIDOptions returns the default options
 func GetDefaultRequestIDOptions() RequestIDOptions {
 	return RequestIDOptions{
-		Generator:         DefaultRequestIDGenerator,
+		Provider:          provider.DefaultRequestID,
 		RequestHeader:     []string{"X-Request-ID", "Cf-Ray"},
 		ResponseHeader:    "X-Request-ID",
 		SetRequestHeader:  true,
@@ -68,9 +62,9 @@ func RequestIDWithSetResponseHeader(v bool) RequestIDOption {
 }
 
 // RequestIDWithGenerator middleware option
-func RequestIDWithGenerator(v RequestIDGenerator) RequestIDOption {
+func RequestIDWithGenerator(v provider.RequestID) RequestIDOption {
 	return func(o *RequestIDOptions) {
-		o.Generator = v
+		o.Provider = v
 	}
 }
 
@@ -103,7 +97,7 @@ func RequestIDWithOptions(opts RequestIDOptions) Middleware {
 				}
 			}
 			if requestID == "" {
-				requestID = opts.Generator()
+				requestID = opts.Provider()
 			}
 			if requestID != "" && opts.SetContext {
 				r = r.WithContext(keelhttpcontext.SetRequestID(r.Context(), requestID))

net/http/provider/requestidprovider.go

@@ -0,0 +1,12 @@
+package provider
+
+import (
+	"github.com/google/uuid"
+)
+
+type RequestID func() string
+
+// DefaultRequestID function
+func DefaultRequestID() string {
+	return uuid.New().String()
+}

net/http/roundtripware/requestid.go

@@ -6,20 +6,23 @@ import (
 	"go.uber.org/zap"
 
 	keelhttpcontext "github.com/foomo/keel/net/http/context"
+	"github.com/foomo/keel/net/http/provider"
 )
 
 type (
 	RequestIDOptions struct {
-		Header string
+		Header    string
+		Provider  provider.RequestID
+		SetHeader bool
 	}
-	RequestIDOption    func(*RequestIDOptions)
-	RequestIDGenerator func() string
+	RequestIDOption func(*RequestIDOptions)
 )
 
 // GetDefaultRequestIDOptions returns the default options
 func GetDefaultRequestIDOptions() RequestIDOptions {
 	return RequestIDOptions{
-		Header: "X-Request-ID",
+		Header:   "X-Request-ID",
+		Provider: provider.DefaultRequestID,
 	}
 }
 
@@ -30,6 +33,13 @@ func RequestIDWithHeader(v string) RequestIDOption {
 	}
 }
 
+// RequestIDWithProvider middleware option
+func RequestIDWithProvider(v provider.RequestID) RequestIDOption {
+	return func(o *RequestIDOptions) {
+		o.Provider = v
+	}
+}
+
 // RequestID returns a RoundTripper which prints out the request & response object
 func RequestID(opts ...RequestIDOption) RoundTripware {
 	o := GetDefaultRequestIDOptions()
@@ -41,8 +51,15 @@ func RequestID(opts ...RequestIDOption) RoundTripware {
 	return func(l *zap.Logger, next Handler) Handler {
 		return func(r *http.Request) (*http.Response, error) {
 			if value := r.Header.Get(o.Header); value == "" {
+				var requestID string
 				if value, ok := keelhttpcontext.GetRequestID(r.Context()); ok && value != "" {
-					r.Header.Set(o.Header, value)
+					requestID = value
+				}
+				if requestID == "" {
+					requestID = o.Provider()
+				}
+				if requestID != "" {
+					r.Header.Set(o.Header, requestID)
 				}
 			}
 			return next(r)