package kubernetes

import (
	"context"
	"fmt"
	"testing"

	"github.com/coredns/coredns/plugin/kubernetes/object"
	"github.com/coredns/coredns/plugin/pkg/dnstest"
	"github.com/coredns/coredns/plugin/test"
	"github.com/coredns/coredns/request"

	"github.com/miekg/dns"
	api "k8s.io/api/core/v1"
	meta "k8s.io/apimachinery/pkg/apis/meta/v1"
	mcs "sigs.k8s.io/mcs-api/pkg/apis/v1alpha1"
)

type kubeTestCase struct {
	Upstream  Upstreamer
	Truncated bool
	test.Case
}

// test cases working for both regular and multicluster zone
var commonDnsTestCases = []kubeTestCase{
	// A Service
	{Case: test.Case{
		Qname: "svc1.testns.svc.cluster.local.", Qtype: dns.TypeA,
		Rcode: dns.RcodeSuccess,
		Answer: []dns.RR{
			test.A("svc1.testns.svc.cluster.local.	5	IN	A	10.0.0.1"),
		},
	}},
	{Case: test.Case{
		Qname: "svcempty.testns.svc.cluster.local.", Qtype: dns.TypeA,
		Rcode: dns.RcodeSuccess,
		Answer: []dns.RR{
			test.A("svcempty.testns.svc.cluster.local.	5	IN	A	10.0.0.1"),
		},
	}},
	{Case: test.Case{
		Qname: "svc1.testns.svc.cluster.local.", Qtype: dns.TypeSRV,
		Rcode:  dns.RcodeSuccess,
		Answer: []dns.RR{test.SRV("svc1.testns.svc.cluster.local.	5	IN	SRV	0 100 80 svc1.testns.svc.cluster.local.")},
		Extra:  []dns.RR{test.A("svc1.testns.svc.cluster.local.  5       IN      A       10.0.0.1")},
	}},
	{Case: test.Case{
		Qname: "svcempty.testns.svc.cluster.local.", Qtype: dns.TypeSRV,
		Rcode:  dns.RcodeSuccess,
		Answer: []dns.RR{test.SRV("svcempty.testns.svc.cluster.local.	5	IN	SRV	0 100 80 svcempty.testns.svc.cluster.local.")},
		Extra:  []dns.RR{test.A("svcempty.testns.svc.cluster.local.  5       IN      A       10.0.0.1")},
	}},
	{Case: test.Case{
		Qname: "svc6.testns.svc.cluster.local.", Qtype: dns.TypeSRV,
		Rcode:  dns.RcodeSuccess,
		Answer: []dns.RR{test.SRV("svc6.testns.svc.cluster.local.	5	IN	SRV	0 100 80 svc6.testns.svc.cluster.local.")},
		Extra:  []dns.RR{test.AAAA("svc6.testns.svc.cluster.local.  5       IN      AAAA       1234:abcd::1")},
	}},
	// SRV Service
	{Case: test.Case{
		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.	5	IN	SRV	0 100 80 svc1.testns.svc.cluster.local."),
		},
		Extra: []dns.RR{
			test.A("svc1.testns.svc.cluster.local.	5	IN	A	10.0.0.1"),
		},
	}},
	{Case: test.Case{
		Qname: "_http._tcp.svcempty.testns.svc.cluster.local.", Qtype: dns.TypeSRV,
		Rcode: dns.RcodeSuccess,
		Answer: []dns.RR{
			test.SRV("_http._tcp.svcempty.testns.svc.cluster.local.	5	IN	SRV	0 100 80 svcempty.testns.svc.cluster.local."),
		},
		Extra: []dns.RR{
			test.A("svcempty.testns.svc.cluster.local.	5	IN	A	10.0.0.1"),
		},
	}},
	// A Service (Headless)
	{Case: test.Case{
		Qname: "hdls1.testns.svc.cluster.local.", Qtype: dns.TypeA,
		Rcode: dns.RcodeSuccess,
		Answer: []dns.RR{
			test.A("hdls1.testns.svc.cluster.local.	5	IN	A	172.0.0.2"),
			test.A("hdls1.testns.svc.cluster.local.	5	IN	A	172.0.0.3"),
			test.A("hdls1.testns.svc.cluster.local.	5	IN	A	172.0.0.4"),
			test.A("hdls1.testns.svc.cluster.local.	5	IN	A	172.0.0.5"),
		},
	}},
	// A Service (Headless and Portless)
	{Case: test.Case{
		Qname: "hdlsprtls.testns.svc.cluster.local.", Qtype: dns.TypeA,
		Rcode: dns.RcodeSuccess,
		Answer: []dns.RR{
			test.A("hdlsprtls.testns.svc.cluster.local.	5	IN	A	172.0.0.20"),
		},
	}},
	// AAAA Service (with an existing A record, but no AAAA record)
	{Case: test.Case{
		Qname: "svc1.testns.svc.cluster.local.", Qtype: dns.TypeAAAA,
		Rcode: dns.RcodeSuccess,
		Ns: []dns.RR{
			test.SOA("cluster.local.	5	IN	SOA	ns.dns.cluster.local. hostmaster.cluster.local. 1499347823 7200 1800 86400 5"),
		},
	}},
	// AAAA Service (non-existing service)
	{Case: test.Case{
		Qname: "svc0.testns.svc.cluster.local.", Qtype: dns.TypeAAAA,
		Rcode: dns.RcodeNameError,
		Ns: []dns.RR{
			test.SOA("cluster.local.	5	IN	SOA	ns.dns.cluster.local. hostmaster.cluster.local. 1499347823 7200 1800 86400 5"),
		},
	}},
	// A Service (non-existing service)
	{Case: test.Case{
		Qname: "svc0.testns.svc.cluster.local.", Qtype: dns.TypeA,
		Rcode: dns.RcodeNameError,
		Ns: []dns.RR{
			test.SOA("cluster.local.	5	IN	SOA	ns.dns.cluster.local. hostmaster.cluster.local. 1499347823 7200 1800 86400 5"),
		},
	}},
	// A Service (non-existing namespace)
	{Case: test.Case{
		Qname: "svc0.svc-nons.svc.cluster.local.", Qtype: dns.TypeA,
		Rcode: dns.RcodeNameError,
		Ns: []dns.RR{
			test.SOA("cluster.local.	5	IN	SOA	ns.dns.cluster.local. hostmaster.cluster.local. 1499347823 7200 1800 86400 5"),
		},
	}},
	// TXT Schema
	{Case: test.Case{
		Qname: "dns-version.cluster.local.", Qtype: dns.TypeTXT,
		Rcode: dns.RcodeSuccess,
		Answer: []dns.RR{
			test.TXT("dns-version.cluster.local 28800 IN TXT 1.1.0"),
		},
	}},
	// A TXT record does not exist but another record for the same FQDN does
	{Case: test.Case{
		Qname: "svc1.testns.svc.cluster.local.", Qtype: dns.TypeTXT,
		Rcode: dns.RcodeSuccess,
		Ns: []dns.RR{
			test.SOA("cluster.local.	5	IN	SOA	ns.dns.cluster.local. hostmaster.cluster.local. 1499347823 7200 1800 86400 5"),
		},
	}},
	// A TXT record does not exist and neither does another record for the same FQDN
	{Case: test.Case{
		Qname: "svc0.svc-nons.svc.cluster.local.", Qtype: dns.TypeTXT,
		Rcode: dns.RcodeNameError,
		Ns: []dns.RR{
			test.SOA("cluster.local.	5	IN	SOA	ns.dns.cluster.local. hostmaster.cluster.local. 1499347823 7200 1800 86400 5"),
		},
	}},
	// A Service (Headless) does not exist
	{Case: test.Case{
		Qname: "bogusendpoint.hdls1.testns.svc.cluster.local.", Qtype: dns.TypeA,
		Rcode: dns.RcodeNameError,
		Ns: []dns.RR{
			test.SOA("cluster.local.	5	IN	SOA	ns.dns.cluster.local. hostmaster.cluster.local. 1499347823 7200 1800 86400 5"),
		},
	}},
	// A Service does not exist
	{Case: test.Case{
		Qname: "bogusendpoint.svc0.testns.svc.cluster.local.", Qtype: dns.TypeA,
		Rcode: dns.RcodeNameError,
		Ns: []dns.RR{
			test.SOA("cluster.local.	5	IN	SOA	ns.dns.cluster.local. hostmaster.cluster.local. 1499347823 7200 1800 86400 5"),
		},
	}},
	// AAAA Service
	{Case: test.Case{
		Qname: "svc6.testns.svc.cluster.local.", Qtype: dns.TypeAAAA,
		Rcode: dns.RcodeSuccess,
		Answer: []dns.RR{
			test.AAAA("svc6.testns.svc.cluster.local.	5	IN	AAAA	1234:abcd::1"),
		},
	}},
	// SRV
	{Case: test.Case{
		Qname: "_http._tcp.svc6.testns.svc.cluster.local.", Qtype: dns.TypeSRV,
		Rcode: dns.RcodeSuccess,
		Answer: []dns.RR{
			test.SRV("_http._tcp.svc6.testns.svc.cluster.local.	5	IN	SRV	0 100 80 svc6.testns.svc.cluster.local."),
		},
		Extra: []dns.RR{
			test.AAAA("svc6.testns.svc.cluster.local.	5	IN	AAAA	1234:abcd::1"),
		},
	}},
	// AAAA Service (Headless)
	{Case: test.Case{
		Qname: "hdls1.testns.svc.cluster.local.", Qtype: dns.TypeAAAA,
		Rcode: dns.RcodeSuccess,
		Answer: []dns.RR{
			test.AAAA("hdls1.testns.svc.cluster.local.	5	IN	AAAA	5678:abcd::1"),
			test.AAAA("hdls1.testns.svc.cluster.local.	5	IN	AAAA	5678:abcd::2"),
		},
	}},

	{Case: test.Case{
		Qname: "svc.cluster.local.", Qtype: dns.TypeA,
		Rcode: dns.RcodeSuccess,
		Ns: []dns.RR{
			test.SOA("cluster.local.	5	IN	SOA	ns.dns.cluster.local. hostmaster.cluster.local. 1499347823 7200 1800 86400 5"),
		},
	}},
	{Case: test.Case{
		Qname: "pod.cluster.local.", Qtype: dns.TypeA,
		Rcode: dns.RcodeSuccess,
		Ns: []dns.RR{
			test.SOA("cluster.local.	5	IN	SOA	ns.dns.cluster.local. hostmaster.cluster.local. 1499347823 7200 1800 86400 5"),
		},
	}},
	{Case: test.Case{
		Qname: "testns.svc.cluster.local.", Qtype: dns.TypeA,
		Rcode: dns.RcodeSuccess,
		Ns: []dns.RR{
			test.SOA("cluster.local.	5	IN	SOA	ns.dns.cluster.local. hostmaster.cluster.local. 1499347823 7200 1800 86400 5"),
		},
	}},
	// NS query for qname != zone (existing domain)
	{Case: test.Case{
		Qname: "svc.cluster.local.", Qtype: dns.TypeNS,
		Rcode: dns.RcodeSuccess,
		Ns: []dns.RR{
			test.SOA("cluster.local.	5	IN	SOA	ns.dns.cluster.local. hostmaster.cluster.local. 1499347823 7200 1800 86400 5"),
		},
	}},
	// NS query for qname != zone (existing domain)
	{Case: test.Case{
		Qname: "testns.svc.cluster.local.", Qtype: dns.TypeNS,
		Rcode: dns.RcodeSuccess,
		Ns: []dns.RR{
			test.SOA("cluster.local.	5	IN	SOA	ns.dns.cluster.local. hostmaster.cluster.local. 1499347823 7200 1800 86400 5"),
		},
	}},
	// NS query for qname != zone (non existing domain)
	{Case: test.Case{
		Qname: "foo.cluster.local.", Qtype: dns.TypeNS,
		Rcode: dns.RcodeNameError,
		Ns: []dns.RR{
			test.SOA("cluster.local.	5	IN	SOA	ns.dns.cluster.local. hostmaster.cluster.local. 1499347823 7200 1800 86400 5"),
		},
	}},
	// NS query for qname != zone (non existing domain)
	{Case: test.Case{
		Qname: "foo.svc.cluster.local.", Qtype: dns.TypeNS,
		Rcode: dns.RcodeNameError,
		Ns: []dns.RR{
			test.SOA("cluster.local.	5	IN	SOA	ns.dns.cluster.local. hostmaster.cluster.local. 1499347823 7200 1800 86400 5"),
		},
	}},
	// Dual Stack ClusterIP Services
	{Case: test.Case{
		Qname: "svc-dual-stack.testns.svc.cluster.local.", Qtype: dns.TypeA,
		Rcode: dns.RcodeSuccess,
		Answer: []dns.RR{
			test.A("svc-dual-stack.testns.svc.cluster.local.	5	IN	A	10.0.0.3"),
		},
	}},
	{Case: test.Case{
		Qname: "svc-dual-stack.testns.svc.cluster.local.", Qtype: dns.TypeAAAA,
		Rcode: dns.RcodeSuccess,
		Answer: []dns.RR{
			test.AAAA("svc-dual-stack.testns.svc.cluster.local.	5	IN	AAAA	10::3"),
		},
	}},
	{Case: test.Case{
		Qname: "svc-dual-stack.testns.svc.cluster.local.", Qtype: dns.TypeSRV,
		Rcode:  dns.RcodeSuccess,
		Answer: []dns.RR{test.SRV("svc-dual-stack.testns.svc.cluster.local.	5	IN	SRV	0 50 80 svc-dual-stack.testns.svc.cluster.local.")},
		Extra: []dns.RR{
			test.A("svc-dual-stack.testns.svc.cluster.local.  5       IN      A       10.0.0.3"),
			test.AAAA("svc-dual-stack.testns.svc.cluster.local.  5       IN      AAAA       10::3"),
		},
	}},
	{Case: test.Case{
		Qname: "svc1.testns.svc.cluster.local.", Qtype: dns.TypeSOA,
		Rcode: dns.RcodeSuccess,
		Ns: []dns.RR{
			test.SOA("cluster.local.	5	IN	SOA	ns.dns.cluster.local. hostmaster.cluster.local. 1499347823 7200 1800 86400 5"),
		},
	}},
	// A query for a subdomain of an external service should not resolve to the external service
	{Case: test.Case{
		Qname: "endpoint.external.testns.svc.cluster.local.", Qtype: dns.TypeCNAME,
		Rcode: dns.RcodeNameError,
		Ns: []dns.RR{
			test.SOA("cluster.local.	5	IN	SOA	ns.dns.cluster.local. hostmaster.cluster.local. 1499347823 7200 1800 86400 5"),
		},
	}},
	// A query for a subdomain of a subdomain of an external service should not resolve to the external service
	{Case: test.Case{
		Qname: "subdomain.subdomain.external.testns.svc.cluster.local.", Qtype: dns.TypeCNAME,
		Rcode: dns.RcodeNameError,
		Ns: []dns.RR{
			test.SOA("cluster.local.	5	IN	SOA	ns.dns.cluster.local. hostmaster.cluster.local. 1499347823 7200 1800 86400 5"),
		},
	}},
}

var dnsTestCases = []kubeTestCase{
	// SRV Service (Headless)
	{Case: test.Case{
		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.	5	IN	SRV	0 16 80 172-0-0-2.hdls1.testns.svc.cluster.local."),
			test.SRV("_http._tcp.hdls1.testns.svc.cluster.local.	5	IN	SRV	0 16 80 172-0-0-3.hdls1.testns.svc.cluster.local."),
			test.SRV("_http._tcp.hdls1.testns.svc.cluster.local.	5	IN	SRV	0 16 80 5678-abcd--1.hdls1.testns.svc.cluster.local."),
			test.SRV("_http._tcp.hdls1.testns.svc.cluster.local.	5	IN	SRV	0 16 80 5678-abcd--2.hdls1.testns.svc.cluster.local."),
			test.SRV("_http._tcp.hdls1.testns.svc.cluster.local.	5	IN	SRV	0 16 80 dup-name.hdls1.testns.svc.cluster.local."),
		},
		Extra: []dns.RR{
			test.A("172-0-0-2.hdls1.testns.svc.cluster.local.	5	IN	A	172.0.0.2"),
			test.A("172-0-0-3.hdls1.testns.svc.cluster.local.	5	IN	A	172.0.0.3"),
			test.AAAA("5678-abcd--1.hdls1.testns.svc.cluster.local.	5	IN	AAAA	5678:abcd::1"),
			test.AAAA("5678-abcd--2.hdls1.testns.svc.cluster.local.	5	IN	AAAA	5678:abcd::2"),
			test.A("dup-name.hdls1.testns.svc.cluster.local.	5	IN	A	172.0.0.4"),
			test.A("dup-name.hdls1.testns.svc.cluster.local.	5	IN	A	172.0.0.5"),
		},
	}},
	{Case: test.Case{ // An A record query for an existing headless service should return a record for each of its ipv4 endpoints
		Qname: "hdls1.testns.svc.cluster.local.", Qtype: dns.TypeA,
		Rcode: dns.RcodeSuccess,
		Answer: []dns.RR{
			test.A("hdls1.testns.svc.cluster.local.	5	IN	A	172.0.0.2"),
			test.A("hdls1.testns.svc.cluster.local.	5	IN	A	172.0.0.3"),
			test.A("hdls1.testns.svc.cluster.local.	5	IN	A	172.0.0.4"),
			test.A("hdls1.testns.svc.cluster.local.	5	IN	A	172.0.0.5"),
		},
	}},
	// AAAA
	{Case: test.Case{
		Qname: "5678-abcd--2.hdls1.testns.svc.cluster.local", Qtype: dns.TypeAAAA,
		Rcode:  dns.RcodeSuccess,
		Answer: []dns.RR{test.AAAA("5678-abcd--2.hdls1.testns.svc.cluster.local.	5	IN	AAAA	5678:abcd::2")},
	}},
	// AAAA Endpoint
	{Case: test.Case{
		Qname: "5678-abcd--1.hdls1.testns.svc.cluster.local.", Qtype: dns.TypeAAAA,
		Rcode: dns.RcodeSuccess,
		Answer: []dns.RR{
			test.AAAA("5678-abcd--1.hdls1.testns.svc.cluster.local.	5	IN	AAAA	5678:abcd::1"),
		},
	}},
	// An Endpoint with no port
	{Case: test.Case{
		Qname: "172-0-0-20.hdlsprtls.testns.svc.cluster.local.", Qtype: dns.TypeA,
		Rcode: dns.RcodeSuccess,
		Answer: []dns.RR{
			test.A("172-0-0-20.hdlsprtls.testns.svc.cluster.local.	5	IN	A	172.0.0.20"),
		},
	}},
	// An Endpoint ip
	{Case: test.Case{
		Qname: "172-0-0-2.hdls1.testns.svc.cluster.local.", Qtype: dns.TypeA,
		Rcode: dns.RcodeSuccess,
		Answer: []dns.RR{
			test.A("172-0-0-2.hdls1.testns.svc.cluster.local.	5	IN	A	172.0.0.2"),
		},
	}},
	// A Endpoint ip
	{Case: test.Case{
		Qname: "172-0-0-3.hdls1.testns.svc.cluster.local.", Qtype: dns.TypeA,
		Rcode: dns.RcodeSuccess,
		Answer: []dns.RR{
			test.A("172-0-0-3.hdls1.testns.svc.cluster.local.	5	IN	A	172.0.0.3"),
		},
	}},
	// An Endpoint by name
	{Case: test.Case{
		Qname: "dup-name.hdls1.testns.svc.cluster.local.", Qtype: dns.TypeA,
		Rcode: dns.RcodeSuccess,
		Answer: []dns.RR{
			test.A("dup-name.hdls1.testns.svc.cluster.local.	5	IN	A	172.0.0.4"),
			test.A("dup-name.hdls1.testns.svc.cluster.local.	5	IN	A	172.0.0.5"),
		},
	}},
	// CNAME External
	{Case: test.Case{
		Qname: "external.testns.svc.cluster.local.", Qtype: dns.TypeCNAME,
		Rcode: dns.RcodeSuccess,
		Answer: []dns.RR{
			test.CNAME("external.testns.svc.cluster.local.	5	IN	CNAME	ext.interwebs.test."),
		},
	}},
	// CNAME External Truncated Lookup
	{
		Case: test.Case{
			Qname: "external.testns.svc.cluster.local.", Qtype: dns.TypeA,
			Rcode: dns.RcodeSuccess,
			Answer: []dns.RR{
				test.A("ext.interwebs.test.	5	IN	A	1.2.3.4"),
				test.CNAME("external.testns.svc.cluster.local.	5	IN	CNAME	ext.interwebs.test."),
			},
		},
		Upstream: &Upstub{
			Truncated: true,
			Qclass:    dns.ClassINET,
			Case: test.Case{
				Qname: "external.testns.svc.cluster.local.",
				Qtype: dns.TypeA,
				Answer: []dns.RR{
					test.A("ext.interwebs.test.	5	IN	A	1.2.3.4"),
					test.CNAME("external.testns.svc.cluster.local.	5	IN	CNAME	ext.interwebs.test."),
				},
			},
		},
		Truncated: true,
	},
	// CNAME External To Internal Service
	{Case: test.Case{
		Qname: "external-to-service.testns.svc.cluster.local", Qtype: dns.TypeA,
		Rcode: dns.RcodeSuccess,
		Answer: []dns.RR{
			test.CNAME("external-to-service.testns.svc.cluster.local.	5	IN	CNAME	svc1.testns.svc.cluster.local."),
			test.A("svc1.testns.svc.cluster.local.	5	IN	A	10.0.0.1"),
		},
	}},
}

func TestServeDNS(t *testing.T) {
	k := New([]string{"cluster.local."})
	k.APIConn = &APIConnServeTest{}
	k.Next = test.NextHandler(dns.RcodeSuccess, nil)
	k.Namespaces = map[string]struct{}{"testns": {}}
	ctx := context.TODO()

	for i, tc := range append(commonDnsTestCases, dnsTestCases...) {
		k.Upstream = tc.Upstream

		r := tc.Msg()

		w := dnstest.NewRecorder(&test.ResponseWriter{})

		_, err := k.ServeDNS(ctx, w, r)
		if err != tc.Error {
			t.Errorf("Test %d expected no error, got %v", i, err)
			return
		}
		if tc.Error != nil {
			continue
		}

		resp := w.Msg
		if resp == nil {
			t.Fatalf("Test %d, got nil message and no error for %q", i, r.Question[0].Name)
		}

		if tc.Truncated != resp.Truncated {
			t.Errorf("Expected truncation %t, got truncation %t", tc.Truncated, resp.Truncated)
		}

		// Before sorting, make sure that CNAMES do not appear after their target records
		if err := test.CNAMEOrder(resp); err != nil {
			t.Errorf("Test %d, %v", i, err)
		}

		if err := test.SortAndCheck(resp, tc.Case); err != nil {
			t.Errorf("Test %d, %v", i, err)
		}
	}
}

var multiclusterDnsTestCases = []kubeTestCase{
	// SRV Service (Headless)
	{Case: test.Case{
		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.	5	IN	SRV	0 16 80 172-0-0-2.cluster1.hdls1.testns.svc.cluster.local."),
			test.SRV("_http._tcp.hdls1.testns.svc.cluster.local.	5	IN	SRV	0 16 80 172-0-0-3.cluster1.hdls1.testns.svc.cluster.local."),
			test.SRV("_http._tcp.hdls1.testns.svc.cluster.local.	5	IN	SRV	0 16 80 5678-abcd--1.cluster1.hdls1.testns.svc.cluster.local."),
			test.SRV("_http._tcp.hdls1.testns.svc.cluster.local.	5	IN	SRV	0 16 80 5678-abcd--2.cluster1.hdls1.testns.svc.cluster.local."),
			test.SRV("_http._tcp.hdls1.testns.svc.cluster.local.	5	IN	SRV	0 16 80 dup-name.cluster1.hdls1.testns.svc.cluster.local."),
		},
		Extra: []dns.RR{
			test.A("172-0-0-2.cluster1.hdls1.testns.svc.cluster.local.	5	IN	A	172.0.0.2"),
			test.A("172-0-0-3.cluster1.hdls1.testns.svc.cluster.local.	5	IN	A	172.0.0.3"),
			test.AAAA("5678-abcd--1.cluster1.hdls1.testns.svc.cluster.local.	5	IN	AAAA	5678:abcd::1"),
			test.AAAA("5678-abcd--2.cluster1.hdls1.testns.svc.cluster.local.	5	IN	AAAA	5678:abcd::2"),
			test.A("dup-name.cluster1.hdls1.testns.svc.cluster.local.	5	IN	A	172.0.0.4"),
			test.A("dup-name.cluster1.hdls1.testns.svc.cluster.local.	5	IN	A	172.0.0.5"),
		},
	}},
	{Case: test.Case{ // An A record query for an existing headless service should return a record for each of its ipv4 endpoints
		Qname: "hdls1.testns.svc.cluster.local.", Qtype: dns.TypeA,
		Rcode: dns.RcodeSuccess,
		Answer: []dns.RR{
			test.A("hdls1.testns.svc.cluster.local.	5	IN	A	172.0.0.2"),
			test.A("hdls1.testns.svc.cluster.local.	5	IN	A	172.0.0.3"),
			test.A("hdls1.testns.svc.cluster.local.	5	IN	A	172.0.0.4"),
			test.A("hdls1.testns.svc.cluster.local.	5	IN	A	172.0.0.5"),
		},
	}},
	// AAAA
	{Case: test.Case{
		Qname: "5678-abcd--2.cluster1.hdls1.testns.svc.cluster.local", Qtype: dns.TypeAAAA,
		Rcode:  dns.RcodeSuccess,
		Answer: []dns.RR{test.AAAA("5678-abcd--2.cluster1.hdls1.testns.svc.cluster.local.	5	IN	AAAA	5678:abcd::2")},
	}},
	// AAAA Endpoint
	{Case: test.Case{
		Qname: "5678-abcd--1.cluster1.hdls1.testns.svc.cluster.local.", Qtype: dns.TypeAAAA,
		Rcode: dns.RcodeSuccess,
		Answer: []dns.RR{
			test.AAAA("5678-abcd--1.cluster1.hdls1.testns.svc.cluster.local.	5	IN	AAAA	5678:abcd::1"),
		},
	}},
	// An Endpoint with no port
	{Case: test.Case{
		Qname: "172-0-0-20.cluster1.hdlsprtls.testns.svc.cluster.local.", Qtype: dns.TypeA,
		Rcode: dns.RcodeSuccess,
		Answer: []dns.RR{
			test.A("172-0-0-20.cluster1.hdlsprtls.testns.svc.cluster.local.	5	IN	A	172.0.0.20"),
		},
	}},
	// AAAA Endpoint without specifying the clusterid
	{Case: test.Case{
		Qname: "5678-abcd--1.hdls1.testns.svc.cluster.local.", Qtype: dns.TypeAAAA,
		Rcode: dns.RcodeNameError,
		Ns: []dns.RR{
			test.SOA("cluster.local.	5	IN	SOA	ns.dns.cluster.local. hostmaster.cluster.local. 1499347823 7200 1800 86400 5"),
		},
	}},
	// An Endpoint ip
	{Case: test.Case{
		Qname: "172-0-0-2.cluster1.hdls1.testns.svc.cluster.local.", Qtype: dns.TypeA,
		Rcode: dns.RcodeSuccess,
		Answer: []dns.RR{
			test.A("172-0-0-2.cluster1.hdls1.testns.svc.cluster.local.	5	IN	A	172.0.0.2"),
		},
	}},
	// A Endpoint ip
	{Case: test.Case{
		Qname: "172-0-0-3.cluster1.hdls1.testns.svc.cluster.local.", Qtype: dns.TypeA,
		Rcode: dns.RcodeSuccess,
		Answer: []dns.RR{
			test.A("172-0-0-3.cluster1.hdls1.testns.svc.cluster.local.	5	IN	A	172.0.0.3"),
		},
	}},
	// An Endpoint by name
	{Case: test.Case{
		Qname: "dup-name.cluster1.hdls1.testns.svc.cluster.local.", Qtype: dns.TypeA,
		Rcode: dns.RcodeSuccess,
		Answer: []dns.RR{
			test.A("dup-name.cluster1.hdls1.testns.svc.cluster.local.	5	IN	A	172.0.0.4"),
			test.A("dup-name.cluster1.hdls1.testns.svc.cluster.local.	5	IN	A	172.0.0.5"),
		},
	}},
}

func TestMultiClusterServeDNS(t *testing.T) {
	k := New([]string{"cluster.local."})
	k.opts.multiclusterZones = []string{"cluster.local."}
	k.APIConn = &APIConnServeTest{}
	k.Next = test.NextHandler(dns.RcodeSuccess, nil)
	k.Namespaces = map[string]struct{}{"testns": {}}
	ctx := context.TODO()

	for i, tc := range append(commonDnsTestCases, multiclusterDnsTestCases...) {
		k.Upstream = tc.Upstream

		r := tc.Msg()

		w := dnstest.NewRecorder(&test.ResponseWriter{})

		_, err := k.ServeDNS(ctx, w, r)
		if err != tc.Error {
			t.Errorf("Test %d expected no error, got %v", i, err)
			return
		}
		if tc.Error != nil {
			continue
		}

		resp := w.Msg
		if resp == nil {
			t.Fatalf("Test %d, got nil message and no error for %q", i, r.Question[0].Name)
		}

		if tc.Truncated != resp.Truncated {
			t.Errorf("Expected truncation %t, got truncation %t", tc.Truncated, resp.Truncated)
		}

		// Before sorting, make sure that CNAMES do not appear after their target records
		if err := test.CNAMEOrder(resp); err != nil {
			t.Errorf("Test %d, %v", i, err)
		}

		if err := test.SortAndCheck(resp, tc.Case); err != nil {
			t.Errorf("Test %d, %v", i, err)
		}
	}
}

var nsTestCases = []test.Case{
	// A Service for an "exposed" namespace that "does exist"
	{
		Qname: "svc1.testns.svc.cluster.local.", Qtype: dns.TypeA,
		Rcode: dns.RcodeSuccess,
		Answer: []dns.RR{
			test.A("svc1.testns.svc.cluster.local.	5	IN	A	10.0.0.1"),
		},
	},
	// A service for an "exposed" namespace that "doesn't exist"
	{
		Qname: "svc1.nsnoexist.svc.cluster.local.", Qtype: dns.TypeA,
		Rcode: dns.RcodeNameError,
		Ns: []dns.RR{
			test.SOA("cluster.local.	300	IN	SOA	ns.dns.cluster.local. hostmaster.cluster.local. 1551484803 7200 1800 86400 30"),
		},
	},
}

func TestServeNamespaceDNS(t *testing.T) {
	k := New([]string{"cluster.local."})
	k.APIConn = &APIConnServeTest{}
	k.Next = test.NextHandler(dns.RcodeSuccess, nil)
	// if no namespaces are explicitly exposed, then they are all implicitly exposed
	k.Namespaces = map[string]struct{}{}
	ctx := context.TODO()

	for i, tc := range nsTestCases {
		r := tc.Msg()

		w := dnstest.NewRecorder(&test.ResponseWriter{})

		_, err := k.ServeDNS(ctx, w, r)
		if err != tc.Error {
			t.Errorf("Test %d expected no error, got %v", i, err)
			return
		}
		if tc.Error != nil {
			continue
		}

		resp := w.Msg
		if resp == nil {
			t.Fatalf("Test %d, got nil message and no error for %q", i, r.Question[0].Name)
		}

		// Before sorting, make sure that CNAMES do not appear after their target records
		test.CNAMEOrder(resp)

		test.SortAndCheck(resp, tc)
	}
}

var notSyncedTestCases = []test.Case{
	{
		// We should get ServerFailure instead of NameError for missing records when we kubernetes hasn't synced
		Qname: "svc0.testns.svc.cluster.local.", Qtype: dns.TypeA,
		Rcode: dns.RcodeServerFailure,
		Ns: []dns.RR{
			test.SOA("cluster.local.	5	IN	SOA	ns.dns.cluster.local. hostmaster.cluster.local. 1499347823 7200 1800 86400 5"),
		},
	},
}

func TestNotSyncedServeDNS(t *testing.T) {
	k := New([]string{"cluster.local."})
	k.APIConn = &APIConnServeTest{
		notSynced: true,
	}
	k.Next = test.NextHandler(dns.RcodeSuccess, nil)
	k.Namespaces = map[string]struct{}{"testns": {}}
	ctx := context.TODO()

	for i, tc := range notSyncedTestCases {
		r := tc.Msg()

		w := dnstest.NewRecorder(&test.ResponseWriter{})

		_, err := k.ServeDNS(ctx, w, r)
		if err != tc.Error {
			t.Errorf("Test %d expected no error, got %v", i, err)
			return
		}
		if tc.Error != nil {
			continue
		}

		resp := w.Msg
		if resp == nil {
			t.Fatalf("Test %d, got nil message and no error for %q", i, r.Question[0].Name)
		}

		if err := test.CNAMEOrder(resp); err != nil {
			t.Error(err)
		}

		if err := test.SortAndCheck(resp, tc); err != nil {
			t.Error(err)
		}
	}
}

type APIConnServeTest struct {
	notSynced bool
}

func (a APIConnServeTest) HasSynced() bool                           { return !a.notSynced }
func (APIConnServeTest) Run()                                        {}
func (APIConnServeTest) Stop() error                                 { return nil }
func (APIConnServeTest) EpIndexReverse(string) []*object.Endpoints   { return nil }
func (APIConnServeTest) SvcIndexReverse(string) []*object.Service    { return nil }
func (APIConnServeTest) SvcExtIndexReverse(string) []*object.Service { return nil }
func (APIConnServeTest) Modified(ModifiedMode) int64                 { return int64(3) }

func (APIConnServeTest) PodIndex(ip string) []*object.Pod {
	if ip != "10.240.0.1" {
		return []*object.Pod{}
	}
	a := []*object.Pod{
		{
			Namespace: "podns", Name: "foo", PodIP: "10.240.0.1",
			Labels: map[string]string{
				"app.kubernetes.io/name": "foo",
				"bar":                    "baz",
			},
		}, // Remote IP set in test.ResponseWriter
	}
	return a
}

var svcIndex = map[string][]*object.Service{
	"kubedns.kube-system": {
		{
			Name:       "kubedns",
			Namespace:  "kube-system",
			Type:       api.ServiceTypeClusterIP,
			ClusterIPs: []string{"10.0.0.10"},
			Ports: []api.ServicePort{
				{Name: "dns", Protocol: "udp", Port: 53},
			},
		},
	},
	"svc1.testns": {
		{
			Name:       "svc1",
			Namespace:  "testns",
			Type:       api.ServiceTypeClusterIP,
			ClusterIPs: []string{"10.0.0.1"},
			Ports: []api.ServicePort{
				{Name: "http", Protocol: "tcp", Port: 80},
			},
		},
	},
	"svcempty.testns": {
		{
			Name:       "svcempty",
			Namespace:  "testns",
			Type:       api.ServiceTypeClusterIP,
			ClusterIPs: []string{"10.0.0.1"},
			Ports: []api.ServicePort{
				{Name: "http", Protocol: "tcp", Port: 80},
			},
		},
	},
	"svc6.testns": {
		{
			Name:       "svc6",
			Namespace:  "testns",
			Type:       api.ServiceTypeClusterIP,
			ClusterIPs: []string{"1234:abcd::1"},
			Ports: []api.ServicePort{
				{Name: "http", Protocol: "tcp", Port: 80},
			},
		},
	},
	"hdls1.testns": {
		{
			Name:       "hdls1",
			Namespace:  "testns",
			Type:       api.ServiceTypeClusterIP,
			ClusterIPs: []string{api.ClusterIPNone},
		},
	},
	"external.testns": {
		{
			Name:         "external",
			Namespace:    "testns",
			ExternalName: "ext.interwebs.test",
			Type:         api.ServiceTypeExternalName,
			Ports: []api.ServicePort{
				{Name: "http", Protocol: "tcp", Port: 80},
			},
		},
	},
	"external-to-service.testns": {
		{
			Name:         "external-to-service",
			Namespace:    "testns",
			ExternalName: "svc1.testns.svc.cluster.local.",
			Type:         api.ServiceTypeExternalName,
			Ports: []api.ServicePort{
				{Name: "http", Protocol: "tcp", Port: 80},
			},
		},
	},
	"hdlsprtls.testns": {
		{
			Name:       "hdlsprtls",
			Namespace:  "testns",
			Type:       api.ServiceTypeClusterIP,
			ClusterIPs: []string{api.ClusterIPNone},
		},
	},
	"svc1.unexposedns": {
		{
			Name:       "svc1",
			Namespace:  "unexposedns",
			Type:       api.ServiceTypeClusterIP,
			ClusterIPs: []string{"10.0.0.2"},
			Ports: []api.ServicePort{
				{Name: "http", Protocol: "tcp", Port: 80},
			},
		},
	},
	"svc-dual-stack.testns": {
		{
			Name:       "svc-dual-stack",
			Namespace:  "testns",
			Type:       api.ServiceTypeClusterIP,
			ClusterIPs: []string{"10.0.0.3", "10::3"}, Ports: []api.ServicePort{
				{Name: "http", Protocol: "tcp", Port: 80},
			},
		},
	},
}

func (APIConnServeTest) SvcIndex(s string) []*object.Service { return svcIndex[s] }

func (APIConnServeTest) ServiceList() []*object.Service {
	svcs := make([]*object.Service, 0, len(svcIndex))
	for _, svc := range svcIndex {
		svcs = append(svcs, svc...)
	}
	return svcs
}

var epsIndex = map[string][]*object.Endpoints{
	"kubedns.kube-system": {{
		Subsets: []object.EndpointSubset{
			{
				Addresses: []object.EndpointAddress{
					{IP: "172.0.0.100"},
				},
				Ports: []object.EndpointPort{
					{Port: 53, Protocol: "udp", Name: "dns"},
				},
			},
		},
		Name:      "kubedns",
		Namespace: "kube-system",
		Index:     object.EndpointsKey("kubedns", "kube-system"),
	}},
	"svc1.testns": {{
		Subsets: []object.EndpointSubset{
			{
				Addresses: []object.EndpointAddress{
					{IP: "172.0.0.1", Hostname: "ep1a"},
				},
				Ports: []object.EndpointPort{
					{Port: 80, Protocol: "tcp", Name: "http"},
				},
			},
		},
		Name:      "svc1-slice1",
		Namespace: "testns",
		Index:     object.EndpointsKey("svc1", "testns"),
	}},
	"svcempty.testns": {{
		Subsets: []object.EndpointSubset{
			{
				Addresses: nil,
				Ports: []object.EndpointPort{
					{Port: 80, Protocol: "tcp", Name: "http"},
				},
			},
		},
		Name:      "svcempty-slice1",
		Namespace: "testns",
		Index:     object.EndpointsKey("svcempty", "testns"),
	}},
	"hdls1.testns": {{
		Subsets: []object.EndpointSubset{
			{
				Addresses: []object.EndpointAddress{
					{IP: "172.0.0.2"},
					{IP: "172.0.0.3"},
					{IP: "172.0.0.4", Hostname: "dup-name"},
					{IP: "172.0.0.5", Hostname: "dup-name"},
					{IP: "5678:abcd::1"},
					{IP: "5678:abcd::2"},
				},
				Ports: []object.EndpointPort{
					{Port: 80, Protocol: "tcp", Name: "http"},
				},
			},
		},
		Name:      "hdls1-slice1",
		Namespace: "testns",
		Index:     object.EndpointsKey("hdls1", "testns"),
	}},
	"hdlsprtls.testns": {{
		Subsets: []object.EndpointSubset{
			{
				Addresses: []object.EndpointAddress{
					{IP: "172.0.0.20"},
				},
				Ports: []object.EndpointPort{{Port: -1}},
			},
		},
		Name:      "hdlsprtls-slice1",
		Namespace: "testns",
		Index:     object.EndpointsKey("hdlsprtls", "testns"),
	}},
}

func (APIConnServeTest) EpIndex(s string) []*object.Endpoints {
	return epsIndex[s]
}

var svcImportIndex = map[string][]*object.ServiceImport{
	"kubedns.kube-system": {
		{
			Name:       "kubedns",
			Namespace:  "kube-system",
			Type:       mcs.ClusterSetIP,
			ClusterIPs: []string{"10.0.0.10"},
			Ports: []mcs.ServicePort{
				{Name: "dns", Protocol: "udp", Port: 53},
			},
		},
	},
	"svc1.testns": {
		{
			Name:       "svc1",
			Namespace:  "testns",
			Type:       mcs.ClusterSetIP,
			ClusterIPs: []string{"10.0.0.1"},
			Ports: []mcs.ServicePort{
				{Name: "http", Protocol: "tcp", Port: 80},
			},
		},
	},
	"svcempty.testns": {
		{
			Name:       "svcempty",
			Namespace:  "testns",
			Type:       mcs.ClusterSetIP,
			ClusterIPs: []string{"10.0.0.1"},
			Ports: []mcs.ServicePort{
				{Name: "http", Protocol: "tcp", Port: 80},
			},
		},
	},
	"svc6.testns": {
		{
			Name:       "svc6",
			Namespace:  "testns",
			Type:       mcs.ClusterSetIP,
			ClusterIPs: []string{"1234:abcd::1"},
			Ports: []mcs.ServicePort{
				{Name: "http", Protocol: "tcp", Port: 80},
			},
		},
	},
	"hdls1.testns": {
		{
			Name:       "hdls1",
			Namespace:  "testns",
			Type:       mcs.Headless,
			ClusterIPs: []string{},
		},
	},
	"hdlsprtls.testns": {
		{
			Name:      "hdlsprtls",
			Namespace: "testns",
			Type:      mcs.Headless,
		},
	},
	"svc1.unexposedns": {
		{
			Name:       "svc1",
			Namespace:  "unexposedns",
			Type:       mcs.ClusterSetIP,
			ClusterIPs: []string{"10.0.0.2"},
			Ports: []mcs.ServicePort{
				{Name: "http", Protocol: "tcp", Port: 80},
			},
		},
	},
	"svc-dual-stack.testns": {
		{
			Name:       "svc-dual-stack",
			Namespace:  "testns",
			Type:       mcs.ClusterSetIP,
			ClusterIPs: []string{"10.0.0.3", "10::3"},
			Ports: []mcs.ServicePort{
				{Name: "http", Protocol: "tcp", Port: 80},
			},
		},
	},
}

func (APIConnServeTest) SvcImportIndex(s string) []*object.ServiceImport { return svcImportIndex[s] }

func (APIConnServeTest) ServiceImportList() []*object.ServiceImport {
	svcs := make([]*object.ServiceImport, 0, len(svcImportIndex))
	for _, svc := range svcImportIndex {
		svcs = append(svcs, svc...)
	}
	return svcs
}

var mcEpsIndex = map[string][]*object.MultiClusterEndpoints{
	"kubedns.kube-system": {{
		Endpoints: object.Endpoints{
			Subsets: []object.EndpointSubset{
				{
					Addresses: []object.EndpointAddress{
						{IP: "172.0.0.100"},
					},
					Ports: []object.EndpointPort{
						{Port: 53, Protocol: "udp", Name: "dns"},
					},
				},
			},
			Name:      "kubedns",
			Namespace: "kube-system",
			Index:     object.EndpointsKey("kubedns", "kube-system"),
		},
		ClusterId: "cluster1",
	}},
	"svc1.testns": {{
		Endpoints: object.Endpoints{
			Subsets: []object.EndpointSubset{
				{
					Addresses: []object.EndpointAddress{
						{IP: "172.0.0.1", Hostname: "ep1a"},
					},
					Ports: []object.EndpointPort{
						{Port: 80, Protocol: "tcp", Name: "http"},
					},
				},
			},
			Name:      "svc1-slice1",
			Namespace: "testns",
			Index:     object.EndpointsKey("svc1", "testns"),
		},
		ClusterId: "cluster1",
	}},
	"svcempty.testns": {{
		Endpoints: object.Endpoints{
			Subsets: []object.EndpointSubset{
				{
					Addresses: nil,
					Ports: []object.EndpointPort{
						{Port: 80, Protocol: "tcp", Name: "http"},
					},
				},
			},
			Name:      "svcempty-slice1",
			Namespace: "testns",
			Index:     object.EndpointsKey("svcempty", "testns"),
		},
		ClusterId: "cluster1",
	}},
	"hdls1.testns": {{
		Endpoints: object.Endpoints{
			Subsets: []object.EndpointSubset{
				{
					Addresses: []object.EndpointAddress{
						{IP: "172.0.0.2"},
						{IP: "172.0.0.3"},
						{IP: "172.0.0.4", Hostname: "dup-name"},
						{IP: "172.0.0.5", Hostname: "dup-name"},
						{IP: "5678:abcd::1"},
						{IP: "5678:abcd::2"},
					},
					Ports: []object.EndpointPort{
						{Port: 80, Protocol: "tcp", Name: "http"},
					},
				},
			},
			Name:      "hdls1-slice1",
			Namespace: "testns",
			Index:     object.EndpointsKey("hdls1", "testns"),
		},
		ClusterId: "cluster1",
	}},
	"hdlsprtls.testns": {{
		Endpoints: object.Endpoints{
			Subsets: []object.EndpointSubset{
				{
					Addresses: []object.EndpointAddress{
						{IP: "172.0.0.20"},
					},
					Ports: []object.EndpointPort{{Port: -1}},
				},
			},
			Name:      "hdlsprtls-slice1",
			Namespace: "testns",
			Index:     object.EndpointsKey("hdlsprtls", "testns"),
		},
		ClusterId: "cluster1",
	}},
}

func (APIConnServeTest) McEpIndex(s string) []*object.MultiClusterEndpoints {
	return mcEpsIndex[s]
}

func (APIConnServeTest) MultiClusterEndpointsList() []*object.MultiClusterEndpoints {
	eps := make([]*object.MultiClusterEndpoints, 0, len(mcEpsIndex))
	for _, ep := range mcEpsIndex {
		eps = append(eps, ep...)
	}
	return eps
}

func (APIConnServeTest) EndpointsList() []*object.Endpoints {
	eps := make([]*object.Endpoints, 0, len(epsIndex))
	for _, ep := range epsIndex {
		eps = append(eps, ep...)
	}
	return eps
}

func (APIConnServeTest) GetNodeByName(_ctx context.Context, _name string) (*api.Node, error) {
	return &api.Node{
		ObjectMeta: meta.ObjectMeta{
			Name: "test.node.foo.bar",
		},
	}, nil
}

func (APIConnServeTest) GetNamespaceByName(name string) (*object.Namespace, error) {
	if name == "pod-nons" { // handler_pod_verified_test.go uses this for non-existent namespace.
		return nil, fmt.Errorf("namespace not found")
	}
	if name == "nsnoexist" {
		return nil, fmt.Errorf("namespace not found")
	}
	return &object.Namespace{
		Name: name,
	}, nil
}

// Upstub implements an Upstreamer that returns a set response for test purposes
type Upstub struct {
	test.Case
	Truncated bool
	Qclass    uint16
}

// Lookup returns a set response
func (t *Upstub) Lookup(_ctx context.Context, _state request.Request, _name string, _typ uint16) (*dns.Msg, error) {
	var answer []dns.RR
	// if query type is not CNAME, remove any CNAME with same name as qname from the answer
	if t.Qtype != dns.TypeCNAME {
		for _, a := range t.Answer {
			if c, ok := a.(*dns.CNAME); ok && c.Header().Name == t.Qname {
				continue
			}
			answer = append(answer, a)
		}
	} else {
		answer = t.Answer
	}

	return &dns.Msg{
		MsgHdr: dns.MsgHdr{
			Response:  true,
			Truncated: t.Truncated,
			Rcode:     t.Rcode,
		},
		Question: []dns.Question{{Name: t.Qname, Qtype: t.Qtype, Qclass: t.Qclass}},
		Answer:   answer,
		Extra:    t.Extra,
		Ns:       t.Ns,
	}, nil
}
