add sd for tunnel

handler/tunnel/dialer.go

@@ -0,0 +1,76 @@
+package tunnel
+
+import (
+	"context"
+	"net"
+	"time"
+
+	"github.com/go-gost/core/logger"
+	"github.com/go-gost/core/sd"
+)
+
+type Dialer struct {
+	node    string
+	pool    *ConnectorPool
+	sd      sd.SD
+	retry   int
+	timeout time.Duration
+	log     logger.Logger
+}
+
+func (d *Dialer) Dial(ctx context.Context, network string, tid string) (conn net.Conn, node string, cid string, err error) {
+	retry := d.retry
+	retry = 1
+
+	for i := 0; i < retry; i++ {
+		c := d.pool.Get(network, tid)
+		if c == nil {
+			break
+		}
+
+		conn, err = c.Session().GetConn()
+		if err != nil {
+			d.log.Error(err)
+			continue
+		}
+		node = d.node
+		cid = c.id.String()
+
+		break
+	}
+	if conn != nil || err != nil {
+		return
+	}
+
+	if d.sd == nil {
+		err = ErrTunnelNotAvailable
+		return
+	}
+
+	ss, err := d.sd.Get(ctx, tid)
+	if err != nil {
+		return
+	}
+
+	var service *sd.Service
+	for _, s := range ss {
+		d.log.Debugf("%+v", s)
+		if s.Name != d.node && s.Network == network {
+			service = s
+			break
+		}
+	}
+	if service == nil || service.Address == "" {
+		err = ErrTunnelNotAvailable
+		return
+	}
+
+	node = service.Node
+	cid = service.Name
+
+	dialer := net.Dialer{
+		Timeout: d.timeout,
+	}
+	conn, err = dialer.DialContext(ctx, network, service.Address)
+	return
+}