etcd: Add advertise urls to cli

This patch adds the option to specify URLs to advertise for clients and peers.
This will facilitate etcd communication through nat, where we want to listen
on a local IP, but expose a public IP to clients/peers.

etcd/etcd.go

@@ -176,12 +176,14 @@ type EmbdEtcd struct { // EMBeddeD etcd
 	exitchan    chan struct{}
 	exitTimeout <-chan time.Time
 
-	hostname   string
-	memberID   uint64            // cluster membership id of server if running
-	endpoints  etcdtypes.URLsMap // map of servers a client could connect to
-	clientURLs etcdtypes.URLs    // locations to listen for clients if i am a server
-	serverURLs etcdtypes.URLs    // locations to listen for servers if i am a server (peer)
-	noServer   bool              // disable all server peering if true
+	hostname            string
+	memberID            uint64            // cluster membership id of server if running
+	endpoints           etcdtypes.URLsMap // map of servers a client could connect to
+	clientURLs          etcdtypes.URLs    // locations to listen for clients if i am a server
+	serverURLs          etcdtypes.URLs    // locations to listen for servers if i am a server (peer)
+	advertiseClientURLs etcdtypes.URLs    // client urls to advertise
+	advertiseServerURLs etcdtypes.URLs    // server urls to advertise
+	noServer            bool              // disable all server peering if true
 
 	// local tracked state
 	nominated        etcdtypes.URLsMap // copy of who's nominated to locally track state
@@ -208,7 +210,7 @@ type EmbdEtcd struct { // EMBeddeD etcd
 }
 
 // NewEmbdEtcd creates the top level embedded etcd struct client and server obj.
-func NewEmbdEtcd(hostname string, seeds, clientURLs, serverURLs etcdtypes.URLs, noServer bool, idealClusterSize uint16, flags Flags, prefix string, converger converger.Converger) *EmbdEtcd {
+func NewEmbdEtcd(hostname string, seeds, clientURLs, serverURLs, advertiseClientURLs, advertiseServerURLs etcdtypes.URLs, noServer bool, idealClusterSize uint16, flags Flags, prefix string, converger converger.Converger) *EmbdEtcd {
 	endpoints := make(etcdtypes.URLsMap)
 	if hostname == seedSentinel { // safety
 		return nil
@@ -229,11 +231,13 @@ func NewEmbdEtcd(hostname string, seeds, clientURLs, serverURLs etcdtypes.URLs,
 
 		nominated: make(etcdtypes.URLsMap),
 
-		hostname:   hostname,
-		endpoints:  endpoints,
-		clientURLs: clientURLs,
-		serverURLs: serverURLs,
-		noServer:   noServer,
+		hostname:            hostname,
+		endpoints:           endpoints,
+		clientURLs:          clientURLs,
+		serverURLs:          serverURLs,
+		advertiseClientURLs: advertiseClientURLs,
+		advertiseServerURLs: advertiseServerURLs,
+		noServer:            noServer,
 
 		idealClusterSize: idealClusterSize,
 		converger:        converger,
@@ -1647,14 +1651,23 @@ func (obj *EmbdEtcd) StartServer(newCluster bool, peerURLsMap etcdtypes.URLsMap)
 		initialPeerURLsMap[memberName] = peerURLs
 	}
 
+	aCUrls := obj.clientURLs
+	if len(obj.advertiseClientURLs) > 0 {
+		aCUrls = obj.advertiseClientURLs
+	}
+	aPUrls := peerURLs
+	if len(obj.advertiseServerURLs) > 0 {
+		aPUrls = obj.advertiseServerURLs
+	}
+
 	// embed etcd
 	cfg := embed.NewConfig()
 	cfg.Name = memberName // hostname
 	cfg.Dir = obj.dataDir
-	cfg.ACUrls = obj.clientURLs
-	cfg.APUrls = peerURLs
 	cfg.LCUrls = obj.clientURLs
 	cfg.LPUrls = peerURLs
+	cfg.ACUrls = aCUrls
+	cfg.APUrls = aPUrls
 	cfg.StrictReconfigCheck = false // XXX: workaround https://github.com/coreos/etcd/issues/6305
 
 	cfg.InitialCluster = initialPeerURLsMap.String() // including myself!