Check in the vendor directory

Travis seems to be having issues pulling deps, so we'll have to check in
the vendor directory and prevent the makefile from trying to regenerate
it normally.

vendor/k8s.io/apiserver/pkg/storage/etcd3/preflight/checks.go

@@ -0,0 +1,70 @@
+/*
+Copyright 2017 The Kubernetes 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 preflight
+
+import (
+	"fmt"
+	"math/rand"
+	"net"
+	"net/url"
+	"time"
+)
+
+const connectionTimeout = 1 * time.Second
+
+// EtcdConnection holds the Etcd server list
+type EtcdConnection struct {
+	ServerList []string
+}
+
+func (EtcdConnection) serverReachable(connURL *url.URL) bool {
+	scheme := connURL.Scheme
+	if scheme == "http" || scheme == "https" || scheme == "tcp" {
+		scheme = "tcp"
+	}
+	if conn, err := net.DialTimeout(scheme, connURL.Host, connectionTimeout); err == nil {
+		defer conn.Close()
+		return true
+	}
+	return false
+}
+
+func parseServerURI(serverURI string) (*url.URL, error) {
+	connURL, err := url.Parse(serverURI)
+	if err != nil {
+		return &url.URL{}, fmt.Errorf("unable to parse etcd url: %v", err)
+	}
+	return connURL, nil
+}
+
+// CheckEtcdServers will attempt to reach all etcd servers once. If any
+// can be reached, return true.
+func (con EtcdConnection) CheckEtcdServers() (done bool, err error) {
+	// Attempt to reach every Etcd server randomly.
+	serverNumber := len(con.ServerList)
+	serverPerms := rand.Perm(serverNumber)
+	for _, index := range serverPerms {
+		host, err := parseServerURI(con.ServerList[index])
+		if err != nil {
+			return false, err
+		}
+		if con.serverReachable(host) {
+			return true, nil
+		}
+	}
+	return false, nil
+}