Stop hardcoding things

Signed-off-by: Miek Gieben <miek@miek.nl>

plugin/traffic/README.md

@@ -42,7 +42,7 @@ traffic TO...
 The extended syntax is available is you want more control.
 
 ~~~
-traffic {
+traffic TO... {
     server SERVER [SERVER]...
     node ID
  }
@@ -60,9 +60,11 @@ names. For example if the Server Block specifies `lb.example.org` as one of the
 
 ## Examples
 
-~~~ corefile
+~~~
 lb.example.org {
-    traffic grpc://127.0.0.1:18000
+    traffic grpc://127.0.0.1:18000 {
+        node test-id
+    }
     debug
     log
 }

plugin/traffic/setup.go

@@ -55,8 +55,14 @@ func setup(c *caddy.Controller) error {
 func parseTraffic(c *caddy.Controller) (*Traffic, error) {
 	node := "coredns"
 	toHosts := []string{}
+	t := &Traffic{}
 	var err error
 
+	t.origins = make([]string, len(c.ServerBlockKeys))
+	for i := range c.ServerBlockKeys {
+		t.origins[i] = plugin.Host(c.ServerBlockKeys[i]).Normalize()
+	}
+
 	for c.Next() {
 		args := c.RemainingArgs()
 		if len(args) < 1 {
@@ -70,8 +76,8 @@ func parseTraffic(c *caddy.Controller) (*Traffic, error) {
 			if !strings.HasPrefix(toHosts[i], transport.GRPC+"://") {
 				return nil, fmt.Errorf("not a %s scheme: %s", transport.GRPC, toHosts[i])
 			}
-			// now cut the prefix off again, because the dialer needs to see normal address strings. All this
-			// grpc:// stuff is to enfore uniformaty accross plugins and future proofing for other protocols.
+			// now cut the prefix off again, because the dialler needs to see normal address strings. All this
+			// grpc:// stuff is to enforce uniform across plugins and future proofing for other protocols.
 			toHosts[i] = toHosts[i][len(transport.GRPC+"://"):]
 		}
 		for c.NextBlock() {
@@ -88,12 +94,10 @@ func parseTraffic(c *caddy.Controller) (*Traffic, error) {
 		}
 	}
 
-	// TODO: only the first host is used.
-	x, err := xds.New(toHosts[0], node)
-	if err != nil {
+	// TODO: only the first host is used, need to figure out how to reconcile multiple upstream providers.
+	if t.c, err = xds.New(toHosts[0], node); err != nil {
 		return nil, err
 	}
 
-	t := &Traffic{c: x}
 	return t, nil
 }

plugin/traffic/traffic.go

@@ -2,6 +2,8 @@ package traffic
 
 import (
 	"context"
+	"strings"
+	"time"
 
 	"github.com/coredns/coredns/plugin"
 	"github.com/coredns/coredns/plugin/pkg/dnsutil"
@@ -13,9 +15,10 @@ import (
 
 // Traffic is a plugin that load balances according to assignments.
 type Traffic struct {
-	c    *xds.Client
-	id   string
-	Next plugin.Handler
+	c       *xds.Client
+	id      string
+	origins []string
+	Next    plugin.Handler
 }
 
 // shutdown closes the connection to the managment endpoints and stops any running goroutines.
@@ -25,26 +28,71 @@ func (t *Traffic) shutdown() { t.c.Close() }
 func (t *Traffic) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.Msg) (int, error) {
 	state := request.Request{Req: r, W: w}
 
-	cluster, _ := dnsutil.TrimZone(state.Name(), "example.org")
-	addr := t.c.Select(cluster)
-	if addr == nil {
+	cluster := ""
+	for _, o := range t.origins {
+		println(o, state.Name())
+		if strings.HasSuffix(state.Name(), o) {
+			cluster, _ = dnsutil.TrimZone(state.Name(), o)
+			state.Zone = o
+			break
+		}
+	}
+	if cluster == "" {
+		// TODO(miek): can this actually happen?
 		return plugin.NextOrFailure(t.Name(), t.Next, ctx, w, r)
 	}
 
-	log.Debugf("Found address %q for %q", addr, cluster)
+	addr := t.c.Select(cluster)
+	if addr != nil {
+		log.Debugf("Found endpoint %q for %q", addr, cluster)
+	} else {
+		log.Debugf("No healthy endpoints found for %q", cluster)
+	}
 
-	// assemble reply
 	m := new(dns.Msg)
 	m.SetReply(r)
 
-	m.Answer = []dns.RR{&dns.A{
-		Hdr: dns.RR_Header{Name: state.QName(), Rrtype: dns.TypeA, Class: dns.ClassINET, Ttl: 5},
-		A:   addr,
-	}}
+	if addr == nil {
+		m.Ns = soa(state.Zone)
+		w.WriteMsg(m)
+		return 0, nil
+	}
+
+	switch state.QType() {
+	case dns.TypeA:
+		if addr.To4() == nil { // it's an IPv6 address, return nodata in that case.
+			m.Ns = soa(state.Zone)
+			break
+		}
+		m.Answer = []dns.RR{&dns.A{Hdr: dns.RR_Header{Name: state.QName(), Rrtype: dns.TypeA, Class: dns.ClassINET, Ttl: 5}, A: addr}}
+
+	case dns.TypeAAAA:
+		if addr.To4() != nil { // it's an IPv4 address, return nodata in that case.
+			m.Ns = soa(state.Zone)
+			break
+		}
+		m.Answer = []dns.RR{&dns.AAAA{Hdr: dns.RR_Header{Name: state.QName(), Rrtype: dns.TypeA, Class: dns.ClassINET, Ttl: 5}, AAAA: addr}}
+	default:
+		m.Ns = soa(state.Zone)
+	}
 
 	w.WriteMsg(m)
 	return 0, nil
 }
 
+// soa returns a synthetic so for this zone.
+func soa(z string) []dns.RR {
+	return []dns.RR{&dns.SOA{
+		Hdr:     dns.RR_Header{Name: z, Rrtype: dns.TypeSOA, Class: dns.ClassINET, Ttl: 5},
+		Ns:      dnsutil.Join("ns", z),
+		Mbox:    dnsutil.Join("coredns", z),
+		Serial:  uint32(time.Now().UTC().Unix()),
+		Refresh: 14400,
+		Retry:   3600,
+		Expire:  604800,
+		Minttl:  5,
+	}}
+}
+
 // Name implements the plugin.Handler interface.
 func (t *Traffic) Name() string { return "traffic" }