[VOL-4290] Voltha go library updates for gRPC migration

Change-Id: I1aa2774beb6b7ed7419bc45aeb53fcae8a8ecda0
diff --git a/vendor/github.com/coreos/etcd/etcdserver/api/v2http/http.go b/vendor/github.com/coreos/etcd/etcdserver/api/v2http/http.go
new file mode 100644
index 0000000..589c172
--- /dev/null
+++ b/vendor/github.com/coreos/etcd/etcdserver/api/v2http/http.go
@@ -0,0 +1,74 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package v2http
+
+import (
+	"math"
+	"net/http"
+	"strings"
+	"time"
+
+	"github.com/coreos/etcd/etcdserver/api/etcdhttp"
+	"github.com/coreos/etcd/etcdserver/api/v2http/httptypes"
+	"github.com/coreos/etcd/etcdserver/auth"
+	"github.com/coreos/etcd/pkg/logutil"
+
+	"github.com/coreos/pkg/capnslog"
+)
+
+const (
+	// time to wait for a Watch request
+	defaultWatchTimeout = time.Duration(math.MaxInt64)
+)
+
+var (
+	plog = capnslog.NewPackageLogger("github.com/coreos/etcd", "etcdserver/api/v2http")
+	mlog = logutil.NewMergeLogger(plog)
+)
+
+func writeError(w http.ResponseWriter, r *http.Request, err error) {
+	if err == nil {
+		return
+	}
+	if e, ok := err.(auth.Error); ok {
+		herr := httptypes.NewHTTPError(e.HTTPStatus(), e.Error())
+		if et := herr.WriteTo(w); et != nil {
+			plog.Debugf("error writing HTTPError (%v) to %s", et, r.RemoteAddr)
+		}
+		return
+	}
+	etcdhttp.WriteError(w, r, err)
+}
+
+// allowMethod verifies that the given method is one of the allowed methods,
+// and if not, it writes an error to w.  A boolean is returned indicating
+// whether or not the method is allowed.
+func allowMethod(w http.ResponseWriter, m string, ms ...string) bool {
+	for _, meth := range ms {
+		if m == meth {
+			return true
+		}
+	}
+	w.Header().Set("Allow", strings.Join(ms, ","))
+	http.Error(w, "Method Not Allowed", http.StatusMethodNotAllowed)
+	return false
+}
+
+func requestLogger(handler http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		plog.Debugf("[%s] %s remote:%s", r.Method, r.RequestURI, r.RemoteAddr)
+		handler.ServeHTTP(w, r)
+	})
+}