[VOL-4291] Rw-core updates for gRPC migration
Change-Id: I8d5a554409115b29318089671ca4e1ab3fa98810
diff --git a/vendor/github.com/coreos/etcd/pkg/srv/srv.go b/vendor/github.com/coreos/etcd/pkg/srv/srv.go
new file mode 100644
index 0000000..600061c
--- /dev/null
+++ b/vendor/github.com/coreos/etcd/pkg/srv/srv.go
@@ -0,0 +1,141 @@
+// 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 srv looks up DNS SRV records.
+package srv
+
+import (
+ "fmt"
+ "net"
+ "net/url"
+ "strings"
+
+ "github.com/coreos/etcd/pkg/types"
+)
+
+var (
+ // indirection for testing
+ lookupSRV = net.LookupSRV // net.DefaultResolver.LookupSRV when ctxs don't conflict
+ resolveTCPAddr = net.ResolveTCPAddr
+)
+
+// GetCluster gets the cluster information via DNS discovery.
+// Also sees each entry as a separate instance.
+func GetCluster(service, name, dns string, apurls types.URLs) ([]string, error) {
+ tempName := int(0)
+ tcp2ap := make(map[string]url.URL)
+
+ // First, resolve the apurls
+ for _, url := range apurls {
+ tcpAddr, err := resolveTCPAddr("tcp", url.Host)
+ if err != nil {
+ return nil, err
+ }
+ tcp2ap[tcpAddr.String()] = url
+ }
+
+ stringParts := []string{}
+ updateNodeMap := func(service, scheme string) error {
+ _, addrs, err := lookupSRV(service, "tcp", dns)
+ if err != nil {
+ return err
+ }
+ for _, srv := range addrs {
+ port := fmt.Sprintf("%d", srv.Port)
+ host := net.JoinHostPort(srv.Target, port)
+ tcpAddr, terr := resolveTCPAddr("tcp", host)
+ if terr != nil {
+ err = terr
+ continue
+ }
+ n := ""
+ url, ok := tcp2ap[tcpAddr.String()]
+ if ok {
+ n = name
+ }
+ if n == "" {
+ n = fmt.Sprintf("%d", tempName)
+ tempName++
+ }
+ // SRV records have a trailing dot but URL shouldn't.
+ shortHost := strings.TrimSuffix(srv.Target, ".")
+ urlHost := net.JoinHostPort(shortHost, port)
+ if ok && url.Scheme != scheme {
+ err = fmt.Errorf("bootstrap at %s from DNS for %s has scheme mismatch with expected peer %s", scheme+"://"+urlHost, service, url.String())
+ } else {
+ stringParts = append(stringParts, fmt.Sprintf("%s=%s://%s", n, scheme, urlHost))
+ }
+ }
+ if len(stringParts) == 0 {
+ return err
+ }
+ return nil
+ }
+
+ failCount := 0
+ err := updateNodeMap(service+"-ssl", "https")
+ srvErr := make([]string, 2)
+ if err != nil {
+ srvErr[0] = fmt.Sprintf("error querying DNS SRV records for _%s-ssl %s", service, err)
+ failCount++
+ }
+ err = updateNodeMap(service, "http")
+ if err != nil {
+ srvErr[1] = fmt.Sprintf("error querying DNS SRV records for _%s %s", service, err)
+ failCount++
+ }
+ if failCount == 2 {
+ return nil, fmt.Errorf("srv: too many errors querying DNS SRV records (%q, %q)", srvErr[0], srvErr[1])
+ }
+ return stringParts, nil
+}
+
+type SRVClients struct {
+ Endpoints []string
+ SRVs []*net.SRV
+}
+
+// GetClient looks up the client endpoints for a service and domain.
+func GetClient(service, domain string) (*SRVClients, error) {
+ var urls []*url.URL
+ var srvs []*net.SRV
+
+ updateURLs := func(service, scheme string) error {
+ _, addrs, err := lookupSRV(service, "tcp", domain)
+ if err != nil {
+ return err
+ }
+ for _, srv := range addrs {
+ urls = append(urls, &url.URL{
+ Scheme: scheme,
+ Host: net.JoinHostPort(srv.Target, fmt.Sprintf("%d", srv.Port)),
+ })
+ }
+ srvs = append(srvs, addrs...)
+ return nil
+ }
+
+ errHTTPS := updateURLs(service+"-ssl", "https")
+ errHTTP := updateURLs(service, "http")
+
+ if errHTTPS != nil && errHTTP != nil {
+ return nil, fmt.Errorf("dns lookup errors: %s and %s", errHTTPS, errHTTP)
+ }
+
+ endpoints := make([]string, len(urls))
+ for i := range urls {
+ endpoints[i] = urls[i].String()
+ }
+ return &SRVClients{Endpoints: endpoints, SRVs: srvs}, nil
+}