| 374 | } |
| 375 | |
| 376 | func NewExtResolver() (*ExtResolver, error) { |
| 377 | cfg, err := dns.ClientConfigFromFile("/etc/resolv.conf") |
| 378 | if err != nil { |
| 379 | return nil, err |
| 380 | } |
| 381 | |
| 382 | if overrideServ != "" && overrideServ != "system-default" { |
| 383 | host, port, err := net.SplitHostPort(overrideServ) |
| 384 | if err != nil { |
| 385 | panic(err) |
| 386 | } |
| 387 | cfg.Servers = []string{host} |
| 388 | cfg.Port = port |
| 389 | } |
| 390 | |
| 391 | if len(cfg.Servers) == 0 { |
| 392 | cfg.Servers = []string{"127.0.0.1"} |
| 393 | } |
| 394 | |
| 395 | cl := new(dns.Client) |
| 396 | cl.Dialer = &net.Dialer{ |
| 397 | Timeout: time.Duration(cfg.Timeout) * time.Second, |
| 398 | } |
| 399 | return &ExtResolver{ |
| 400 | cl: cl, |
| 401 | Cfg: cfg, |
| 402 | }, nil |
| 403 | } |