distribution/vendor/github.com/miekg/dns/clientconfig.go
Derek McGowan a685e3fc98
Replace godep with vndr
Vndr has a simpler configuration and allows pointing to forked
packages. Additionally other docker projects are now using
vndr making vendoring in distribution more consistent.

Updates letsencrypt to use fork.
No longer uses sub-vendored packages.

Signed-off-by: Derek McGowan <derek@mcgstyle.net> (github: dmcgowan)
2016-11-23 15:07:06 -08:00

100 lines
2.2 KiB
Go

package dns
import (
"bufio"
"os"
"strconv"
"strings"
)
// ClientConfig wraps the contents of the /etc/resolv.conf file.
type ClientConfig struct {
Servers []string // servers to use
Search []string // suffixes to append to local name
Port string // what port to use
Ndots int // number of dots in name to trigger absolute lookup
Timeout int // seconds before giving up on packet
Attempts int // lost packets before giving up on server, not used in the package dns
}
// ClientConfigFromFile parses a resolv.conf(5) like file and returns
// a *ClientConfig.
func ClientConfigFromFile(resolvconf string) (*ClientConfig, error) {
file, err := os.Open(resolvconf)
if err != nil {
return nil, err
}
defer file.Close()
c := new(ClientConfig)
scanner := bufio.NewScanner(file)
c.Servers = make([]string, 0)
c.Search = make([]string, 0)
c.Port = "53"
c.Ndots = 1
c.Timeout = 5
c.Attempts = 2
for scanner.Scan() {
if err := scanner.Err(); err != nil {
return nil, err
}
line := scanner.Text()
f := strings.Fields(line)
if len(f) < 1 {
continue
}
switch f[0] {
case "nameserver": // add one name server
if len(f) > 1 {
// One more check: make sure server name is
// just an IP address. Otherwise we need DNS
// to look it up.
name := f[1]
c.Servers = append(c.Servers, name)
}
case "domain": // set search path to just this domain
if len(f) > 1 {
c.Search = make([]string, 1)
c.Search[0] = f[1]
} else {
c.Search = make([]string, 0)
}
case "search": // set search path to given servers
c.Search = make([]string, len(f)-1)
for i := 0; i < len(c.Search); i++ {
c.Search[i] = f[i+1]
}
case "options": // magic options
for i := 1; i < len(f); i++ {
s := f[i]
switch {
case len(s) >= 6 && s[:6] == "ndots:":
n, _ := strconv.Atoi(s[6:])
if n < 1 {
n = 1
}
c.Ndots = n
case len(s) >= 8 && s[:8] == "timeout:":
n, _ := strconv.Atoi(s[8:])
if n < 1 {
n = 1
}
c.Timeout = n
case len(s) >= 8 && s[:9] == "attempts:":
n, _ := strconv.Atoi(s[9:])
if n < 1 {
n = 1
}
c.Attempts = n
case s == "rotate":
/* not imp */
}
}
}
}
return c, nil
}