readd the 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/http/http.go

@@ -0,0 +1,59 @@
+// Package http resolves ids to network addresses using a http request
+package http
+
+import (
+	"encoding/json"
+	"io/ioutil"
+	"net/http"
+	"net/url"
+
+	"github.com/micro/go-micro/network/resolver"
+)
+
+type Resolver struct {
+	// If not set, defaults to http
+	Proto string
+
+	// Path sets the path to lookup. Defaults to /network
+	Path string
+}
+
+// Resolve assumes ID is a domain which can be converted to a http://id/network request
+func (r *Resolver) Resolve(id string) ([]*resolver.Record, error) {
+	proto := "http"
+	path := "/network"
+
+	if len(r.Proto) > 0 {
+		proto = r.Proto
+	}
+
+	if len(r.Path) > 0 {
+		path = r.Path
+	}
+
+	uri := &url.URL{
+		Scheme: proto,
+		Path:   path,
+		Host:   id,
+	}
+
+	rsp, err := http.Get(uri.String())
+	if err != nil {
+		return nil, err
+	}
+	defer rsp.Body.Close()
+
+	b, err := ioutil.ReadAll(rsp.Body)
+	if err != nil {
+		return nil, err
+	}
+
+	// encoding format is assumed to be json
+	var records []*resolver.Record
+
+	if err := json.Unmarshal(b, &records); err != nil {
+		return nil, err
+	}
+
+	return records, nil
+}

network/resolver/registry/registry.go

@@ -0,0 +1,37 @@
+// Package registry resolves ids using the go-micro registry
+package registry
+
+import (
+	"github.com/micro/go-micro/network/resolver"
+	"github.com/micro/go-micro/registry"
+)
+
+type Resolver struct {
+	// Registry is the registry to use otherwise we use the defaul
+	Registry registry.Registry
+}
+
+// Resolve assumes ID is a domain name e.g micro.mu
+func (r *Resolver) Resolve(id string) ([]*resolver.Record, error) {
+	reg := r.Registry
+	if reg == nil {
+		reg = registry.DefaultRegistry
+	}
+
+	services, err := reg.GetService(id)
+	if err != nil {
+		return nil, err
+	}
+
+	var records []*resolver.Record
+
+	for _, service := range services {
+		for _, node := range service.Nodes {
+			records = append(records, &resolver.Record{
+				Address: node.Address,
+			})
+		}
+	}
+
+	return records, nil
+}

network/resolver/resolver.go

@@ -0,0 +1,15 @@
+// Package resolver resolves network ids to addresses
+package resolver
+
+// Resolver is network resolver. It's used to find network nodes
+// via id to connect to. This is done based on Network.Id().
+// Before we can be part of any network, we have to connect to it.
+type Resolver interface {
+	// Resolve returns a list of addresses for an id
+	Resolve(id string) ([]*Record, error)
+}
+
+// A resolved record
+type Record struct {
+	Address string `json:"address"`
+}