--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/pkg/middleware/notfound.go	Wed Nov 07 16:08:25 2018 +0100
@@ -0,0 +1,36 @@
+// This is Free Software under GNU Affero General Public License v >= 3.0
+// without warranty, see README.md and license for details.
+//
+// SPDX-License-Identifier: AGPL-3.0-or-later
+// License-Filename: LICENSES/AGPL-3.0.txt
+//
+// Copyright (C) 2018 by via donau
+//   – Österreichische Wasserstraßen-Gesellschaft mbH
+// Software engineering by Intevation GmbH
+//
+// Author(s):
+//  * Sascha L. Teichmann <sascha.teichmann@intevation.de>
+
+package middleware
+
+import (
+	"errors"
+	"net/http"
+)
+
+var ErrNotFound = errors.New("Not found")
+
+func NotFound(next http.Handler) http.Handler {
+	return http.HandlerFunc(func(rw http.ResponseWriter, req *http.Request) {
+		defer func() {
+			if p := recover(); p != nil {
+				if p == ErrNotFound {
+					http.NotFound(rw, req)
+				} else {
+					panic(p)
+				}
+			}
+		}()
+		next.ServeHTTP(rw, req)
+	})
+}