k8s/autopath: Add CNAMES (#771)

* Add unit tests & cnames

* more progress

* fix

* next mw dependent unit tests

* add tests for OnNXDOMAIN

* Add AAAA and ndots unit tests; fix request.NewWithQuestion

* Correct default value in README

* add CNAMEs to readme

* review

* fix autopath examples

* fix and test CNAME response order

1 files changed, 462 insertions, 0 deletions

diff --git a/middleware/kubernetes/handler_test.go b/middleware/kubernetes/handler_test.go
new file mode 100644
index 000000000..6d045ebd1
--- /dev/null
+++ b/middleware/kubernetes/handler_test.go
@@ -0,0 +1,462 @@
+package kubernetes
+
+import (
+	"net"
+	"sort"
+	"testing"
+
+	"github.com/coredns/coredns/middleware/pkg/dnsrecorder"
+	"github.com/coredns/coredns/middleware/test"
+
+	"github.com/miekg/dns"
+	"golang.org/x/net/context"
+	"k8s.io/client-go/1.5/pkg/api"
+)
+
+var dnsTestCases = map[string](*test.Case){
+	"A Service": {
+		Qname: "svc1.testns.svc.cluster.local.", Qtype: dns.TypeA,
+		Rcode: dns.RcodeSuccess,
+		Answer: []dns.RR{
+			test.A("svc1.testns.svc.cluster.local.	0	IN	A	10.0.0.1"),
+		},
+	},
+	"A Service (Headless)": {
+		Qname: "hdls1.testns.svc.cluster.local.", Qtype: dns.TypeA,
+		Rcode: dns.RcodeSuccess,
+		Answer: []dns.RR{
+			test.A("hdls1.testns.svc.cluster.local.	0	IN	A	172.0.0.2"),
+			test.A("hdls1.testns.svc.cluster.local.	0	IN	A	172.0.0.3"),
+		},
+	},
+	"SRV Service": {
+		Qname: "_http._tcp.svc1.testns.svc.cluster.local.", Qtype: dns.TypeSRV,
+		Rcode: dns.RcodeSuccess,
+		Answer: []dns.RR{
+			test.SRV("_http._tcp.svc1.testns.svc.cluster.local.	0	IN	SRV	0 100 80 svc1.testns.svc.cluster.local."),
+		},
+		Extra: []dns.RR{
+			test.A("svc1.testns.svc.cluster.local.	0	IN	A	10.0.0.1"),
+		},
+	},
+	"SRV Service (Headless)": {
+		Qname: "_http._tcp.hdls1.testns.svc.cluster.local.", Qtype: dns.TypeSRV,
+		Rcode: dns.RcodeSuccess,
+		Answer: []dns.RR{
+			test.SRV("_http._tcp.hdls1.testns.svc.cluster.local.	0	IN	SRV	0 50 80 172-0-0-2.hdls1.testns.svc.cluster.local."),
+			test.SRV("_http._tcp.hdls1.testns.svc.cluster.local.	0	IN	SRV	0 50 80 172-0-0-3.hdls1.testns.svc.cluster.local."),
+		},
+		Extra: []dns.RR{
+			test.A("172-0-0-2.hdls1.testns.svc.cluster.local.	0	IN	A	172.0.0.2"),
+			test.A("172-0-0-3.hdls1.testns.svc.cluster.local.	0	IN	A	172.0.0.3"),
+		},
+	},
+	// TODO A External
+	"CNAME External": {
+		Qname: "external.testns.svc.cluster.local.", Qtype: dns.TypeCNAME,
+		Rcode: dns.RcodeSuccess,
+		Answer: []dns.RR{
+			test.CNAME("external.testns.svc.cluster.local.	0	IN	CNAME	ext.interwebs.test."),
+		},
+	},
+	"A Service (Local Federated)": {
+		Qname: "svc1.testns.fed.svc.cluster.local.", Qtype: dns.TypeA,
+		Rcode: dns.RcodeSuccess,
+		Answer: []dns.RR{
+			test.A("svc1.testns.fed.svc.cluster.local.	0	IN	A	10.0.0.1"),
+		},
+	},
+	"PTR Service": {
+		Qname: "1.0.0.10.in-addr.arpa.", Qtype: dns.TypePTR,
+		Rcode: dns.RcodeSuccess,
+		Answer: []dns.RR{
+			test.PTR("1.0.0.10.in-addr.arpa.	0	IN	PTR	svc1.testns.svc.cluster.local."),
+		},
+	},
+	// TODO A Service (Remote Federated)
+	"CNAME Service (Remote Federated)": {
+		Qname: "svc0.testns.fed.svc.cluster.local.", Qtype: dns.TypeCNAME,
+		Rcode: dns.RcodeSuccess,
+		Answer: []dns.RR{
+			test.CNAME("svc0.testns.fed.svc.cluster.local.	0	IN	CNAME	svc0.testns.fed.svc.fd-az.fd-r.federal.test."),
+		},
+	},
+}
+
+var autopathCases = map[string](*test.Case){
+	"A Autopath Service (Second Search)": {
+		Qname: "svc1.testns.podns.svc.cluster.local.", Qtype: dns.TypeA,
+		Rcode: dns.RcodeSuccess,
+		Answer: []dns.RR{
+			test.CNAME("svc1.testns.podns.svc.cluster.local.	0	IN	CNAME	svc1.testns.svc.cluster.local."),
+			test.A("svc1.testns.svc.cluster.local.	0	IN	A	10.0.0.1"),
+		},
+	},
+	"A Autopath Service (Third Search)": {
+		Qname: "svc1.testns.svc.podns.svc.cluster.local.", Qtype: dns.TypeA,
+		Rcode: dns.RcodeSuccess,
+		Answer: []dns.RR{
+			test.CNAME("svc1.testns.svc.podns.svc.cluster.local.	0	IN	CNAME	svc1.testns.svc.cluster.local."),
+			test.A("svc1.testns.svc.cluster.local.	0	IN	A	10.0.0.1"),
+		},
+	},
+	"A Autopath Next Middleware (Host Domain Search)": {
+		Qname: "test1.podns.svc.cluster.local.", Qtype: dns.TypeA,
+		Rcode: dns.RcodeSuccess,
+		Answer: []dns.RR{
+			test.CNAME("test1.podns.svc.cluster.local.	0	IN	CNAME	test1.hostdom.test."),
+			test.A("test1.hostdom.test.	0	IN	A	11.22.33.44"),
+		},
+	},
+	"A Autopath Service (Bare Search)": {
+		Qname: "svc1.testns.svc.cluster.local.podns.svc.cluster.local.", Qtype: dns.TypeA,
+		Rcode: dns.RcodeSuccess,
+		Answer: []dns.RR{
+			test.CNAME("svc1.testns.svc.cluster.local.podns.svc.cluster.local.	0	IN	CNAME	svc1.testns.svc.cluster.local."),
+			test.A("svc1.testns.svc.cluster.local.	0	IN	A	10.0.0.1"),
+		},
+	},
+	"A Autopath Next Middleware (Bare Search)": {
+		Qname: "test2.interwebs.podns.svc.cluster.local.", Qtype: dns.TypeA,
+		Rcode: dns.RcodeSuccess,
+		Answer: []dns.RR{
+			test.CNAME("test2.interwebs.podns.svc.cluster.local.	0	IN	CNAME	test2.interwebs."),
+			test.A("test2.interwebs.	0	IN	A	55.66.77.88"),
+		},
+	},
+	"AAAA Autopath Next Middleware (Bare Search)": {
+		Qname: "test2.interwebs.podns.svc.cluster.local.", Qtype: dns.TypeAAAA,
+		Rcode: dns.RcodeSuccess,
+		Answer: []dns.RR{
+			test.CNAME("test2.interwebs.podns.svc.cluster.local.	0	IN	CNAME	test2.interwebs."),
+			test.AAAA("test2.interwebs.	0	IN	AAAA	5555:6666:7777::8888"),
+		},
+	},
+}
+var autopathBareSearch = map[string](*test.Case){
+	"A Autopath Next Middleware (Bare Search) Non-existing OnNXDOMAIN default": {
+		Qname: "nothere.interwebs.podns.svc.cluster.local.", Qtype: dns.TypeA,
+		Rcode:  dns.RcodeSuccess,
+		Answer: []dns.RR{},
+	},
+}
+var autopathBareSearchExpectNameErr = map[string](*test.Case){
+	"A Autopath Next Middleware (Bare Search) Non-existing OnNXDOMAIN disabled": {
+		Qname: "nothere.interwebs.podns.svc.cluster.local.", Qtype: dns.TypeA,
+		Rcode:  dns.RcodeNameError,
+		Answer: []dns.RR{},
+	},
+}
+var autopath2NDotsCases = map[string](*test.Case){
+	"A Service (0 Dots)": {
+		Qname: "foo.podns.svc.cluster.local.", Qtype: dns.TypeA,
+		Rcode:  dns.RcodeNameError,
+		Answer: []dns.RR{},
+		Ns: []dns.RR{
+			test.SOA("cluster.local.	300	IN	SOA	ns.dns.cluster.local. hostmaster.cluster.local. 1499347823 7200 1800 86400 60"),
+		},
+	},
+	"A Service (1 Dots)": {
+		Qname: "foo.foo.podns.svc.cluster.local.", Qtype: dns.TypeA,
+		Rcode:  dns.RcodeNameError,
+		Answer: []dns.RR{},
+		Ns: []dns.RR{
+			test.SOA("cluster.local.	300	IN	SOA	ns.dns.cluster.local. hostmaster.cluster.local. 1499347823 7200 1800 86400 60"),
+		},
+	},
+	"A Service (2 Dots)": {
+		Qname: "foo.foo.foo.podns.svc.cluster.local.", Qtype: dns.TypeA,
+		Rcode: dns.RcodeSuccess,
+		Answer: []dns.RR{
+			test.A("foo.foo.foo.hostdom.test.	0	IN	A	11.22.33.44"),
+			test.CNAME("foo.foo.foo.podns.svc.cluster.local.	0	IN	CNAME	foo.foo.foo.hostdom.test."),
+		},
+	},
+}
+
+func TestServeDNS(t *testing.T) {
+
+	k := Kubernetes{Zones: []string{"cluster.local."}}
+	_, cidr, _ := net.ParseCIDR("10.0.0.0/8")
+
+	k.ReverseCidrs = []net.IPNet{*cidr}
+	k.Federations = []Federation{{name: "fed", zone: "federal.test."}}
+	k.APIConn = &APIConnServeTest{}
+	k.AutoPath.Enabled = true
+	k.AutoPath.HostSearchPath = []string{"hostdom.test"}
+	//k.Proxy = test.MockHandler(nextMWMap)
+	k.Next = testHandler(nextMWMap)
+
+	ctx := context.TODO()
+	runServeDNSTests(t, dnsTestCases, k, ctx)
+	runServeDNSTests(t, autopathCases, k, ctx)
+	runServeDNSTests(t, autopathBareSearch, k, ctx)
+
+	// Set ndots to 2 for the ndots test cases
+	k.AutoPath.NDots = 2
+	runServeDNSTests(t, autopath2NDotsCases, k, ctx)
+	k.AutoPath.NDots = defautNdots
+
+	// Disable the NXDOMAIN override (enabled by default)
+	k.OnNXDOMAIN = dns.RcodeNameError
+	runServeDNSTests(t, autopathCases, k, ctx)
+	runServeDNSTests(t, autopathBareSearchExpectNameErr, k, ctx)
+
+}
+
+func runServeDNSTests(t *testing.T, dnsTestCases map[string](*test.Case), k Kubernetes, ctx context.Context) {
+	for testname, tc := range dnsTestCases {
+		testname = "\nTest Case \"" + testname + "\""
+		r := tc.Msg()
+
+		w := dnsrecorder.New(&test.ResponseWriter{})
+
+		_, err := k.ServeDNS(ctx, w, r)
+		if err != nil {
+			t.Errorf("%v expected no error, got %v\n", testname, err)
+			return
+		}
+
+		resp := w.Msg
+
+		// Before sorting, make sure that CNAMES do not appear after their target records
+		for i, c := range resp.Answer {
+			if c.Header().Rrtype != dns.TypeCNAME {
+				continue
+			}
+			for _, a := range resp.Answer[:i] {
+				if a.Header().Name != c.(*dns.CNAME).Target {
+					continue
+				}
+				t.Errorf("%v: CNAME found after target record\n", testname)
+				t.Logf("%v Received:\n %v\n", testname, resp)
+
+			}
+		}
+
+		sort.Sort(test.RRSet(resp.Answer))
+		sort.Sort(test.RRSet(resp.Ns))
+		sort.Sort(test.RRSet(resp.Extra))
+		sort.Sort(test.RRSet(tc.Answer))
+		sort.Sort(test.RRSet(tc.Ns))
+		sort.Sort(test.RRSet(tc.Extra))
+
+		if !test.Header(t, *tc, resp) {
+			t.Logf("%v Received:\n %v\n", testname, resp)
+			continue
+		}
+		if !test.Section(t, *tc, test.Answer, resp.Answer) {
+			t.Logf("%v Received:\n %v\n", testname, resp)
+		}
+		if !test.Section(t, *tc, test.Ns, resp.Ns) {
+			t.Logf("%v Received:\n %v\n", testname, resp)
+		}
+		if !test.Section(t, *tc, test.Extra, resp.Extra) {
+			t.Logf("%v Received:\n %v\n", testname, resp)
+		}
+	}
+}
+
+// next middleware question->answer map
+
+var nextMWMap = map[dns.Question]dns.Msg{
+	{Name: "test1.hostdom.test.", Qtype: dns.TypeA, Qclass: dns.ClassINET}: {
+		Answer: []dns.RR{test.A("test1.hostdom.test.	0	IN	A	11.22.33.44")},
+	},
+	{Name: "test2.interwebs.", Qtype: dns.TypeA, Qclass: dns.ClassINET}: {
+		Answer: []dns.RR{test.A("test2.interwebs.	0	IN	A	55.66.77.88")},
+	},
+	{Name: "test2.interwebs.", Qtype: dns.TypeAAAA, Qclass: dns.ClassINET}: {
+		Answer: []dns.RR{test.AAAA("test2.interwebs.  0  IN  AAAA  5555:6666:7777::8888")},
+	},
+	{Name: "foo.hostdom.test.", Qtype: dns.TypeA, Qclass: dns.ClassINET}: {
+		Answer: []dns.RR{test.A("foo.hostdom.test.	0	IN	A	11.22.33.44")},
+	},
+	{Name: "foo.foo.hostdom.test.", Qtype: dns.TypeA, Qclass: dns.ClassINET}: {
+		Answer: []dns.RR{test.A("foo.foo.hostdom.test.	0	IN	A	11.22.33.44")},
+	},
+	{Name: "foo.foo.foo.hostdom.test.", Qtype: dns.TypeA, Qclass: dns.ClassINET}: {
+		Answer: []dns.RR{test.A("foo.foo.foo.hostdom.test.	0	IN	A	11.22.33.44")},
+	},
+}
+
+// testHandler returns a Handler that returns an answer for the question in the
+// request per the question->answer map qMap.
+func testHandler(qMap map[dns.Question]dns.Msg) test.Handler {
+	return test.HandlerFunc(func(ctx context.Context, w dns.ResponseWriter, r *dns.Msg) (int, error) {
+		m := new(dns.Msg)
+		m.SetReply(r)
+		msg, ok := qMap[r.Question[0]]
+		if !ok {
+			r.Rcode = dns.RcodeNameError
+			return dns.RcodeNameError, nil
+		}
+		r.Rcode = dns.RcodeSuccess
+		m.Answer = append(m.Answer, msg.Answer...)
+		m.Extra = append(m.Extra, msg.Extra...)
+		w.WriteMsg(m)
+		return dns.RcodeSuccess, nil
+	})
+}
+
+type APIConnServeTest struct{}
+
+func (APIConnServeTest) Run()        { return }
+func (APIConnServeTest) Stop() error { return nil }
+
+func (APIConnServeTest) PodIndex(string) []interface{} {
+	a := make([]interface{}, 1)
+	a[0] = &api.Pod{
+		ObjectMeta: api.ObjectMeta{
+			Namespace: "podns",
+		},
+		Status: api.PodStatus{
+			PodIP: "10.240.0.1", // Remote IP set in test.ResponseWriter
+		},
+	}
+	return a
+}
+
+func (APIConnServeTest) ServiceList() []*api.Service {
+	svcs := []*api.Service{
+		{
+			ObjectMeta: api.ObjectMeta{
+				Name:      "svc1",
+				Namespace: "testns",
+			},
+			Spec: api.ServiceSpec{
+				ClusterIP: "10.0.0.1",
+				Ports: []api.ServicePort{{
+					Name:     "http",
+					Protocol: "tcp",
+					Port:     80,
+				}},
+			},
+		},
+		{
+			ObjectMeta: api.ObjectMeta{
+				Name:      "hdls1",
+				Namespace: "testns",
+			},
+			Spec: api.ServiceSpec{
+				ClusterIP: api.ClusterIPNone,
+			},
+		},
+		{
+			ObjectMeta: api.ObjectMeta{
+				Name:      "external",
+				Namespace: "testns",
+			},
+			Spec: api.ServiceSpec{
+				ExternalName: "ext.interwebs.test",
+				Ports: []api.ServicePort{{
+					Name:     "http",
+					Protocol: "tcp",
+					Port:     80,
+				}},
+			},
+		},
+	}
+	return svcs
+
+}
+
+func (APIConnServeTest) EndpointsList() api.EndpointsList {
+	n := "test.node.foo.bar"
+
+	return api.EndpointsList{
+		Items: []api.Endpoints{
+			{
+				Subsets: []api.EndpointSubset{
+					{
+						Addresses: []api.EndpointAddress{
+							{
+								IP:       "172.0.0.1",
+								Hostname: "ep1a",
+							},
+						},
+						Ports: []api.EndpointPort{
+							{
+								Port:     80,
+								Protocol: "tcp",
+								Name:     "http",
+							},
+						},
+					},
+				},
+				ObjectMeta: api.ObjectMeta{
+					Name:      "svc1",
+					Namespace: "testns",
+				},
+			},
+			{
+				Subsets: []api.EndpointSubset{
+					{
+						Addresses: []api.EndpointAddress{
+							{
+								IP: "172.0.0.2",
+							},
+						},
+						Ports: []api.EndpointPort{
+							{
+								Port:     80,
+								Protocol: "tcp",
+								Name:     "http",
+							},
+						},
+					},
+				},
+				ObjectMeta: api.ObjectMeta{
+					Name:      "hdls1",
+					Namespace: "testns",
+				},
+			},
+			{
+				Subsets: []api.EndpointSubset{
+					{
+						Addresses: []api.EndpointAddress{
+							{
+								IP: "172.0.0.3",
+							},
+						},
+						Ports: []api.EndpointPort{
+							{
+								Port:     80,
+								Protocol: "tcp",
+								Name:     "http",
+							},
+						},
+					},
+				},
+				ObjectMeta: api.ObjectMeta{
+					Name:      "hdls1",
+					Namespace: "testns",
+				},
+			},
+			{
+				Subsets: []api.EndpointSubset{
+					{
+						Addresses: []api.EndpointAddress{
+							{
+								IP:       "10.9.8.7",
+								NodeName: &n,
+							},
+						},
+					},
+				},
+			},
+		},
+	}
+}
+
+func (APIConnServeTest) GetNodeByName(name string) (api.Node, error) {
+	return api.Node{
+		ObjectMeta: api.ObjectMeta{
+			Name: "test.node.foo.bar",
+			Labels: map[string]string{
+				labelRegion:           "fd-r",
+				labelAvailabilityZone: "fd-az",
+			},
+		},
+	}, nil
+}