refactor: make tenant UUIDMiddleware a true middleware func

tenant/composition.go

@@ -175,7 +175,7 @@ func resourcePreHandler(
 ) alice.Chain {
 	authHeaderMiddleware := turtleware.AuthBearerHeaderMiddleware
 	authMiddleware := turtleware.AuthClaimsMiddleware(keySet)
-	tenantUUIDMiddleware := UUIDMiddleware()
+	tenantUUIDMiddleware := UUIDMiddleware
 
 	return alice.New(
 		authHeaderMiddleware,

tenant/middleware_common.go

@@ -27,27 +27,25 @@ var (
 
 // UUIDMiddleware is a http middleware for checking tenant authentication details, and
 // passing down the tenant UUID if existing, or bailing out otherwise.
-func UUIDMiddleware() func(http.Handler) http.Handler {
-	return func(h http.Handler) http.Handler {
-		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-			claims, err := turtleware.AuthClaimsFromRequestContext(r.Context())
-			if err != nil {
-				turtleware.WriteError(r.Context(), w, r, http.StatusInternalServerError, err)
-				return
-			}
-
-			tenantUUID, ok := claims["tenant_uuid"].(string)
-			if !ok || tenantUUID == "" {
-				turtleware.WriteError(r.Context(), w, r, http.StatusBadRequest, ErrTokenMissingTenantUUID)
-				return
-			}
-
-			h.ServeHTTP(
-				w,
-				r.WithContext(context.WithValue(r.Context(), ctxTenantUUID, tenantUUID)),
-			)
-		})
-	}
+func UUIDMiddleware(h http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		claims, err := turtleware.AuthClaimsFromRequestContext(r.Context())
+		if err != nil {
+			turtleware.WriteError(r.Context(), w, r, http.StatusInternalServerError, err)
+			return
+		}
+
+		tenantUUID, ok := claims["tenant_uuid"].(string)
+		if !ok || tenantUUID == "" {
+			turtleware.WriteError(r.Context(), w, r, http.StatusBadRequest, ErrTokenMissingTenantUUID)
+			return
+		}
+
+		h.ServeHTTP(
+			w,
+			r.WithContext(context.WithValue(r.Context(), ctxTenantUUID, tenantUUID)),
+		)
+	})
 }
 
 func UUIDFromRequestContext(ctx context.Context) (string, error) {