add resolver

network/resolver/dns/dns.go

@@ -0,0 +1,30 @@
+// Package dns resolves ids to dns srv records
+package dns
+
+import (
+	"fmt"
+	"net"
+
+	"github.com/micro/go-micro/network/resolver"
+)
+
+type Resolver struct{}
+
+// Resolve assumes ID is a domain name e.g micro.mu
+func (r *Resolver) Resolve(id string) ([]*resolver.Record, error) {
+	_, addrs, err := net.LookupSRV("network", "udp", id)
+	if err != nil {
+		return nil, err
+	}
+	var records []*resolver.Record
+	for _, addr := range addrs {
+		address := addr.Target
+		if addr.Port > 0 {
+			address = fmt.Sprintf("%s:%d", addr.Target, addr.Port)
+		}
+		records = append(records, &resolver.Record{
+			Address: address,
+		})
+	}
+	return records, nil
+}

network/resolver/resolver.go

@@ -0,0 +1,12 @@
+// Package resolver resolves network ids to addresses
+package resolver
+
+type Resolver interface {
+	// Resolve returns a list of addresses for an id
+	Resolve(id string) ([]*Record, error)
+}
+
+// A resoved id
+type Record struct {
+	Address string
+}