@@ -9,7 +9,7 @@ import (

 	"github.com/Sirupsen/logrus"

 	"github.com/docker/docker/opts"

 	"github.com/docker/docker/pkg/promise"

-	"github.com/docker/docker/pkg/resolvconf"

+	"github.com/docker/docker/pkg/resolvconf/dns"

 	"github.com/docker/docker/pkg/signal"

 	"github.com/docker/docker/runconfig"

 )

@@ -65,7 +65,7 @@ func (cli *DockerCli) CmdRun(args ...string) error {

 		// localhost regexp to warn if they are trying to

 		// set a DNS to a localhost address

 		for _, dnsIP := range hostConfig.Dns {

-			if resolvconf.IsLocalhost(dnsIP) {

+			if dns.IsLocalhost(dnsIP) {

 				fmt.Fprintf(cli.err, "WARNING: Localhost DNS setting (--dns=%s) may fail in containers.\n", dnsIP)

 				break

 			}

new file mode 100644

@@ -0,0 +1,16 @@

+package dns

+

+import (

+	"regexp"

+)

+

+const IpLocalhost = `((127\.([0-9]{1,3}.){2}[0-9]{1,3})|(::1))`

+

+var localhostIPRegexp = regexp.MustCompile(IpLocalhost)

+

+// IsLocalhost returns true if ip matches the localhost IP regular expression.

+// Used for determining if nameserver settings are being passed which are

+// localhost addresses

+func IsLocalhost(ip string) bool {

+	return localhostIPRegexp.MatchString(ip)

+}

@@ -10,6 +10,7 @@ import (

 	"github.com/Sirupsen/logrus"

 	"github.com/docker/docker/pkg/ioutils"

+	"github.com/docker/docker/pkg/resolvconf/dns"

 )

 var (

@@ -24,10 +25,8 @@ var (

 	// For readability and sufficiency for Docker purposes this seemed more reasonable than a

 	// 1000+ character regexp with exact and complete IPv6 validation

 	ipv6Address = `([0-9A-Fa-f]{0,4}:){2,7}([0-9A-Fa-f]{0,4})`

-	ipLocalhost = `((127\.([0-9]{1,3}.){2}[0-9]{1,3})|(::1))`

-	localhostIPRegexp = regexp.MustCompile(ipLocalhost)

-	localhostNSRegexp = regexp.MustCompile(`(?m)^nameserver\s+` + ipLocalhost + `\s*\n*`)

+	localhostNSRegexp = regexp.MustCompile(`(?m)^nameserver\s+` + dns.IpLocalhost + `\s*\n*`)

 	nsIPv6Regexp      = regexp.MustCompile(`(?m)^nameserver\s+` + ipv6Address + `\s*\n*`)

 	nsRegexp          = regexp.MustCompile(`^\s*nameserver\s*((` + ipv4Address + `)|(` + ipv6Address + `))\s*$`)

 	searchRegexp      = regexp.MustCompile(`^\s*search\s*(([^\s]+\s*)*)$`)

@@ -128,13 +127,6 @@ func getLines(input []byte, commentMarker []byte) [][]byte {

 	return output

 }

-// IsLocalhost returns true if ip matches the localhost IP regular expression.

-// Used for determining if nameserver settings are being passed which are

-// localhost addresses

-func IsLocalhost(ip string) bool {

-	return localhostIPRegexp.MatchString(ip)

-}

-

 // GetNameservers returns nameservers (if any) listed in /etc/resolv.conf

 func GetNameservers(resolvConf []byte) []string {

 	nameservers := []string{}