gateway: fix the dns discovery method

strip the scheme from the endpoints to have a clean hostname for TCP proxy

Fixes #7452

etcdmain/gateway.go

@@ -19,6 +19,7 @@ import (
 	"net"
 	"os"
 	"time"
+	"net/url"
 
 	"github.com/coreos/etcd/client"
 	"github.com/coreos/etcd/pkg/transport"
@@ -77,6 +78,20 @@ func newGatewayStartCommand() *cobra.Command {
 	return &cmd
 }
 
+func stripSchema(eps []string) []string {
+	var endpoints []string
+
+	for _, ep := range eps {
+
+		if u, err := url.Parse(ep); err == nil && u.Host != "" {
+			ep = u.Host
+		}
+
+		endpoints = append(endpoints, ep)
+	}
+
+	return endpoints
+}
 func startGateway(cmd *cobra.Command, args []string) {
 	endpoints := gatewayEndpoints
 	if gatewayDNSCluster != "" {
@@ -101,6 +116,9 @@ func startGateway(cmd *cobra.Command, args []string) {
 		}
 	}
 
+	// Strip the schema from the endpoints because we start just a TCP proxy
+	endpoints = stripSchema(endpoints)
+
 	if len(endpoints) == 0 {
 		plog.Fatalf("no endpoints found")
 	}

etcdmain/gateway_test.go

@@ -0,0 +1,27 @@
+package etcdmain
+
+import "testing"
+
+func TestStripSchema(t *testing.T) {
+	endpoints := []string{
+		"https://etcd-node:2379",
+		"http://etcd-node:2379",
+		"etcd-node:2379",
+		"etcd-node",
+	}
+
+	expected := []string {
+		"etcd-node:2379",
+		"etcd-node:2379",
+		"etcd-node:2379",
+		"etcd-node",
+	}
+
+	result := stripSchema(endpoints)
+
+	for i, ep := range result {
+		if ep != expected[i] {
+			t.Errorf("Expected stripSchema to return '%v' from '%v' but got '%v'", expected[i], endpoints[i], ep)
+		}
+	}
+}