34 lines
730 B
Go
34 lines
730 B
Go
|
package resolver
|
||
|
|
|
||
|
|
import (
|
||
|
|
"bufio"
|
||
|
|
"os"
|
||
|
|
"strings"
|
||
|
|
)
|
||
|
|
|
||
|
|
// GetDefaultNameserver reads `/etc/resolv.conf` to determine the default
|
||
|
|
// nameserver configured. Returns an error if unable to parse or
|
||
|
|
// no nameserver specified. It returns as soon as it finds a line
|
||
|
|
// with `nameserver` prefix.
|
||
|
|
// An example format:
|
||
|
|
// `nameserver 127.0.0.1`
|
||
|
|
|
||
|
|
func GetDefaultNameserver() (string, error) {
|
||
|
|
file, err := os.Open("/etc/resolv.conf")
|
||
|
|
if err != nil {
|
||
|
|
return "", err
|
||
|
|
}
|
||
|
|
defer file.Close()
|
||
|
|
|
||
|
|
scanner := bufio.NewScanner(file)
|
||
|
|
for scanner.Scan() {
|
||
|
|
if strings.HasPrefix(scanner.Text(), "nameserver") {
|
||
|
|
return strings.Fields(scanner.Text())[1], nil
|
||
|
|
}
|
||
|
|
}
|
||
|
|
if err := scanner.Err(); err != nil {
|
||
|
|
return "", err
|
||
|
|
}
|
||
|
|
return "", err
|
||
|
|
}
|