try grpc lb interface

rpcx/internal/discovclient.go

@@ -0,0 +1,36 @@
+package internal
+
+import (
+	"zero/core/discov"
+	"zero/rpcx/internal/balancer/roundrobin"
+	"zero/rpcx/internal/resolver"
+
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/connectivity"
+)
+
+type DiscovClient struct {
+	conn *grpc.ClientConn
+}
+
+func NewDiscovClient(etcd discov.EtcdConf, opts ...ClientOption) (*DiscovClient, error) {
+	resolver.RegisterResolver(etcd)
+	opts = append(opts, WithDialOption(grpc.WithBalancerName(roundrobin.Name)))
+	conn, err := dial("discov:///", opts...)
+	if err != nil {
+		return nil, err
+	}
+
+	return &DiscovClient{
+		conn: conn,
+	}, nil
+}
+
+func (c *DiscovClient) Next() (*grpc.ClientConn, bool) {
+	state := c.conn.GetState()
+	if state == connectivity.Ready {
+		return c.conn, true
+	} else {
+		return nil, false
+	}
+}