middleware/kubernetes: Implement current federation beta (#723)

* federation initial commit

* UTs/bugfixes

* federation bits

* polish, cover UT gaps

* add TODO

* go fmt & todo note

* remove unrelated change

* pr changes

* start node watcher

* get real node name

* remove unused case

middleware/kubernetes/federation_test.go

@@ -0,0 +1,104 @@
+package kubernetes
+
+import (
+	"net"
+	"strings"
+	"testing"
+
+	"github.com/coredns/coredns/middleware/etcd/msg"
+	"github.com/miekg/dns"
+	"k8s.io/client-go/1.5/pkg/api"
+)
+
+func testStripFederation(t *testing.T, k Kubernetes, input []string, expectedFed string, expectedSegs string) {
+	fed, segs := k.stripFederation(input)
+
+	if expectedSegs != strings.Join(segs, ".") {
+		t.Errorf("For '%v', expected segs result '%v'. Instead got result '%v'.", strings.Join(input, "."), expectedSegs, strings.Join(segs, "."))
+	}
+	if expectedFed != fed {
+		t.Errorf("For '%v', expected fed result '%v'. Instead got result '%v'.", strings.Join(input, "."), expectedFed, fed)
+	}
+}
+
+func TestStripFederation(t *testing.T) {
+	k := Kubernetes{Zones: []string{"inter.webs.test"}}
+	k.Federations = []Federation{{name: "fed", zone: "era.tion.com"}}
+
+	testStripFederation(t, k, []string{"service", "ns", "fed", "svc"}, "fed", "service.ns.svc")
+	testStripFederation(t, k, []string{"service", "ns", "foo", "svc"}, "", "service.ns.foo.svc")
+	testStripFederation(t, k, []string{"foo", "bar"}, "", "foo.bar")
+
+}
+
+type apiConnFedTest struct{}
+
+func (apiConnFedTest) Run()                          { return }
+func (apiConnFedTest) Stop() error                   { return nil }
+func (apiConnFedTest) ServiceList() []*api.Service   { return []*api.Service{} }
+func (apiConnFedTest) PodIndex(string) []interface{} { return nil }
+
+func (apiConnFedTest) EndpointsList() api.EndpointsList {
+	n := "test.node.foo.bar"
+	return api.EndpointsList{
+		Items: []api.Endpoints{
+			{
+				Subsets: []api.EndpointSubset{
+					{
+						Addresses: []api.EndpointAddress{
+							{
+								IP:       "10.9.8.7",
+								NodeName: &n,
+							},
+						},
+					},
+				},
+			},
+		},
+	}
+}
+
+func (apiConnFedTest) GetNodeByName(name string) (api.Node, error) {
+	if name != "test.node.foo.bar" {
+		return api.Node{}, nil
+	}
+	return api.Node{
+		ObjectMeta: api.ObjectMeta{
+			Name: "test.node.foo.bar",
+			Labels: map[string]string{
+				LabelRegion:           "fd-r",
+				LabelAvailabilityZone: "fd-az",
+			},
+		},
+	}, nil
+}
+
+func testFederationCNAMERecord(t *testing.T, k Kubernetes, input recordRequest, expected msg.Service) {
+	svc := k.federationCNAMERecord(input)
+
+	if expected.Host != svc.Host {
+		t.Errorf("For '%v', expected Host result '%v'. Instead got result '%v'.", input, expected.Host, svc.Host)
+	}
+	if expected.Key != svc.Key {
+		t.Errorf("For '%v', expected Key result '%v'. Instead got result '%v'.", input, expected.Key, svc.Key)
+	}
+}
+
+func TestFederationCNAMERecord(t *testing.T) {
+	k := Kubernetes{Zones: []string{"inter.webs"}}
+	k.Federations = []Federation{{name: "fed", zone: "era.tion.com"}}
+	k.APIConn = apiConnFedTest{}
+
+	var r recordRequest
+
+	r, _ = k.parseRequest("s1.ns.fed.svc.inter.webs", dns.TypeA)
+	localPodIP = net.ParseIP("10.9.8.7")
+	testFederationCNAMERecord(t, k, r, msg.Service{Key: "/coredns/webs/inter/svc/fed/ns/s1", Host: "s1.ns.fed.svc.fd-az.fd-r.era.tion.com"})
+
+	r, _ = k.parseRequest("ep1.s1.ns.fed.svc.inter.webs", dns.TypeA)
+	testFederationCNAMERecord(t, k, r, msg.Service{Key: "/coredns/webs/inter/svc/fed/ns/s1/ep1", Host: "ep1.s1.ns.fed.svc.fd-az.fd-r.era.tion.com"})
+
+	r, _ = k.parseRequest("ep1.s1.ns.foo.svc.inter.webs", dns.TypeA)
+	testFederationCNAMERecord(t, k, r, msg.Service{Key: "", Host: ""})
+
+}