Fix etcd-io#11321

Fix issues identified in etcd-io#11321 (comment)

embed/config.go

@@ -37,6 +37,7 @@ import (
 	"go.etcd.io/etcd/pkg/types"
 
 	bolt "go.etcd.io/bbolt"
+	"go.uber.org/multierr"
 	"go.uber.org/zap"
 	"go.uber.org/zap/zapcore"
 	"golang.org/x/crypto/bcrypt"
@@ -603,7 +604,7 @@ func (cfg *Config) PeerURLsMapAndToken(which string) (urlsmap types.URLsMap, tok
 	case cfg.DNSCluster != "":
 		clusterStrs, cerr := cfg.GetDNSClusterNames()
 		lg := cfg.logger
-		if cerr != nil {
+		if len(clusterStrs) == 0 && cerr != nil {
 			lg.Warn("failed to resolve during SRV discovery", zap.Error(cerr))
 			return nil, "", cerr
 		}
@@ -675,7 +676,7 @@ func (cfg *Config) GetDNSClusterNames() ([]string, error) {
 		zap.Error(httpCerr),
 	)
 
-	return clusterStrs, cerr
+	return clusterStrs, multierr.Combine(cerr, httpCerr)
 }
 
 func (cfg Config) InitialClusterFromName(name string) (ret string) {