embed: support experimental v2v3 proxy option

embed/config.go

@@ -145,6 +145,7 @@ type Config struct {
 	// Experimental flags
 
 	ExperimentalCorruptCheckTime time.Duration `json:"experimental-corrupt-check-time"`
+	ExperimentalEnableV2V3       string        `json:"experimental-enable-v2v3"`
 }
 
 // configYAML holds the config suitable for yaml parsing

embed/etcd.go

@@ -29,6 +29,8 @@ import (
 	"github.com/coreos/etcd/etcdserver"
 	"github.com/coreos/etcd/etcdserver/api/etcdhttp"
 	"github.com/coreos/etcd/etcdserver/api/v2http"
+	"github.com/coreos/etcd/etcdserver/api/v2v3"
+	"github.com/coreos/etcd/etcdserver/api/v3client"
 	"github.com/coreos/etcd/etcdserver/api/v3rpc"
 	"github.com/coreos/etcd/pkg/cors"
 	"github.com/coreos/etcd/pkg/debugutil"
@@ -409,7 +411,12 @@ func (e *Etcd) serve() (err error) {
 	// Start a client server goroutine for each listen address
 	var h http.Handler
 	if e.Config().EnableV2 {
-		h = v2http.NewClientHandler(e.Server, e.Server.Cfg.ReqTimeout())
+		if len(e.Config().ExperimentalEnableV2V3) > 0 {
+			srv := v2v3.NewServer(v3client.New(e.Server), e.cfg.ExperimentalEnableV2V3)
+			h = v2http.NewClientHandler(srv, e.Server.Cfg.ReqTimeout())
+		} else {
+			h = v2http.NewClientHandler(e.Server, e.Server.Cfg.ReqTimeout())
+		}
 	} else {
 		mux := http.NewServeMux()
 		etcdhttp.HandleBasic(mux, e.Server)