Make use of cloudflare 1.0.0.1 by default to resolve addresses

network/resolver/dns/dns.go

@@ -2,13 +2,18 @@
 package dns
 
 import (
+	"context"
 	"net"
 
 	"github.com/micro/go-micro/network/resolver"
+	"github.com/miekg/dns"
 )
 
 // Resolver is a DNS network resolve
-type Resolver struct{}
+type Resolver struct {
+	// The resolver address to use
+	Address string
+}
 
 // Resolve assumes ID is a domain name e.g micro.mu
 func (r *Resolver) Resolve(name string) ([]*resolver.Record, error) {
@@ -22,14 +27,29 @@ func (r *Resolver) Resolve(name string) ([]*resolver.Record, error) {
 		host = "localhost"
 	}
 
-	addrs, err := net.LookupHost(host)
+	if len(r.Address) == 0 {
+		r.Address = "1.0.0.1:53"
+	}
+
+	m := new(dns.Msg)
+	m.SetQuestion(dns.Fqdn(host), dns.TypeA)
+	rec, err := dns.ExchangeContext(context.Background(), m, r.Address)
 	if err != nil {
 		return nil, err
 	}
 
-	records := make([]*resolver.Record, 0, len(addrs))
+	var records []*resolver.Record
+
+	for _, answer := range rec.Answer {
+		h := answer.Header()
+		// check record type matches
+		if h.Rrtype != dns.TypeA {
+			continue
+		}
+
+		arec, _ := answer.(*dns.A)
+		addr := arec.A.String()
 
-	for _, addr := range addrs {
 		// join resolved record with port
 		address := net.JoinHostPort(addr, port)
 		// append to record set