DNSResolver: use isd.IsDomain

this commit dedicated to @whyrusleeping

namesys/dns.go

@@ -2,25 +2,29 @@ package namesys
 
 import (
 	"net"
-	"strings"
 
 	b58 "github.com/jbenet/go-ipfs/Godeps/_workspace/src/github.com/jbenet/go-base58"
 	mh "github.com/jbenet/go-ipfs/Godeps/_workspace/src/github.com/jbenet/go-multihash"
 	u "github.com/jbenet/go-ipfs/util"
+	isd "github.com/jbenet/go-is-domain"
 )
 
+// DNSResolver implements a Resolver on DNS domains
 type DNSResolver struct {
 	// TODO: maybe some sort of caching?
 	// cache would need a timeout
 }
 
+// Matches implements Resolver
 func (r *DNSResolver) Matches(name string) bool {
-	return strings.Contains(name, ".") && !strings.HasPrefix(name, ".")
+	return isd.IsDomain(name)
 }
 
+// Resolve implements Resolver
 // TXT records for a given domain name should contain a b58
 // encoded multihash.
 func (r *DNSResolver) Resolve(name string) (string, error) {
+	log.Info("DNSResolver resolving %v", name)
 	txt, err := net.LookupTXT(name)
 	if err != nil {
 		return "", err