Add plugin for Azure DNS (#2945)

* Add plugin for Azure DNS

Signed-off-by: darshanime <deathbullet@gmail.com>

* Rename AzureDNS plugin to Azure

Signed-off-by: darshanime <deathbullet@gmail.com>

* remove upstream from azure syntax

Signed-off-by: darshanime <deathbullet@gmail.com>

* Rename azure plugin block keynames

Signed-off-by: darshanime <deathbullet@gmail.com>

* Normalize zone name before lookup in zones

Signed-off-by: darshanime <deathbullet@gmail.com>

* Update import path for caddy

Signed-off-by: darshanime <deathbullet@gmail.com>

* normalize azure zone name only if required

Signed-off-by: darshanime <deathbullet@gmail.com>

* Add support for MX, SRV, TXT, records

Signed-off-by: darshanime <deathbullet@gmail.com>

* Add specs for new record types

Signed-off-by: darshanime <deathbullet@gmail.com>

* Use sequential updates for zones

Signed-off-by: darshanime <deathbullet@gmail.com>

* Add OWNERS file for azure plugin

Signed-off-by: darshanime <deathbullet@gmail.com>

* Rename imports for third party packages

Signed-off-by: darshanime <deathbullet@gmail.com>

* Capitalize values in README

Signed-off-by: darshanime <deathbullet@gmail.com>

* Shorten keys for azure plugin config

Signed-off-by: darshanime <deathbullet@gmail.com>

* Fixup readme for azure plugin

Signed-off-by: darshanime <deathbullet@gmail.com>

1 files changed, 180 insertions, 0 deletions

diff --git a/plugin/azure/azure_test.go b/plugin/azure/azure_test.go
new file mode 100644
index 000000000..d006f196b
--- /dev/null
+++ b/plugin/azure/azure_test.go
@@ -0,0 +1,180 @@
+package azure
+
+import (
+	"context"
+	"reflect"
+	"testing"
+
+	"github.com/coredns/coredns/plugin/file"
+	"github.com/coredns/coredns/plugin/pkg/dnstest"
+	"github.com/coredns/coredns/plugin/pkg/fall"
+	"github.com/coredns/coredns/plugin/test"
+	"github.com/coredns/coredns/request"
+
+	"github.com/miekg/dns"
+)
+
+var demoAzure = Azure{
+	Next:      testHandler(),
+	Fall:      fall.Zero,
+	zoneNames: []string{"example.org.", "www.example.org.", "example.org.", "sample.example.org."},
+	zones:     testZones(),
+}
+
+func testZones() zones {
+	zones := make(map[string][]*zone)
+	zones["example.org."] = append(zones["example.org."], &zone{zone: "example.org."})
+	newZ := file.NewZone("example.org.", "")
+
+	for _, rr := range []string{
+		"example.org.  300 IN  A   1.2.3.4",
+		"example.org.  300 IN  AAAA   2001:db8:85a3::8a2e:370:7334",
+		"www.example.org.  300 IN  A   1.2.3.4",
+		"www.example.org.  300 IN  A   1.2.3.4",
+		"org.	172800	IN	NS	ns3-06.azure-dns.org.",
+		"org.	300	IN	SOA	ns1-06.azure-dns.com. azuredns-hostmaster.microsoft.com. 1 3600 300 2419200 300",
+		"cname.example.org. 300 IN CNAME example.org",
+		"mail.example.org. 300 IN MX 10 mailserver.example.com",
+		"ptr.example.org. 300 IN PTR www.ptr-example.com",
+		"example.org. 300 IN SRV 1 10 5269 srv-1.example.com.",
+		"example.org. 300 IN SRV 1 10 5269 srv-2.example.com.",
+		"txt.example.org. 300 IN TXT \"TXT for example.org\"",
+	} {
+		r, _ := dns.NewRR(rr)
+		newZ.Insert(r)
+	}
+	zones["example.org."][0].z = newZ
+	return zones
+}
+
+func testHandler() test.HandlerFunc {
+	return func(ctx context.Context, w dns.ResponseWriter, r *dns.Msg) (int, error) {
+		state := request.Request{W: w, Req: r}
+		qname := state.Name()
+		m := new(dns.Msg)
+		rcode := dns.RcodeServerFailure
+		if qname == "example.gov." { // No records match, test fallthrough.
+			m.SetReply(r)
+			rr := test.A("example.gov.  300 IN  A   2.4.6.8")
+			m.Answer = []dns.RR{rr}
+			m.Authoritative = true
+			rcode = dns.RcodeSuccess
+		}
+		m.SetRcode(r, rcode)
+		w.WriteMsg(m)
+		return rcode, nil
+	}
+}
+
+func TestAzure(t *testing.T) {
+	tests := []struct {
+		qname        string
+		qtype        uint16
+		wantRetCode  int
+		wantAnswer   []string
+		wantMsgRCode int
+		wantNS       []string
+		expectedErr  error
+	}{
+		{
+			qname: "example.org.",
+			qtype: dns.TypeA,
+			wantAnswer: []string{"example.org.	300	IN	A	1.2.3.4"},
+		},
+		{
+			qname: "example.org",
+			qtype: dns.TypeAAAA,
+			wantAnswer: []string{"example.org.	300	IN	AAAA	2001:db8:85a3::8a2e:370:7334"},
+		},
+		{
+			qname: "example.org",
+			qtype: dns.TypeSOA,
+			wantAnswer: []string{"org.	300	IN	SOA	ns1-06.azure-dns.com. azuredns-hostmaster.microsoft.com. 1 3600 300 2419200 300"},
+		},
+		{
+			qname:        "badexample.com",
+			qtype:        dns.TypeA,
+			wantRetCode:  dns.RcodeServerFailure,
+			wantMsgRCode: dns.RcodeServerFailure,
+		},
+		{
+			qname: "example.gov",
+			qtype: dns.TypeA,
+			wantAnswer: []string{"example.gov.	300	IN	A	2.4.6.8"},
+		},
+		{
+			qname: "example.org",
+			qtype: dns.TypeSRV,
+			wantAnswer: []string{"example.org.	300	IN	SRV	1 10 5269 srv-1.example.com.", "example.org.	300	IN	SRV	1 10 5269 srv-2.example.com."},
+		},
+		{
+			qname: "cname.example.org.",
+			qtype: dns.TypeCNAME,
+			wantAnswer: []string{"cname.example.org.	300	IN	CNAME	example.org."},
+		},
+		{
+			qname: "cname.example.org.",
+			qtype: dns.TypeA,
+			wantAnswer: []string{"cname.example.org.	300	IN	CNAME	example.org.", "example.org.	300	IN	A	1.2.3.4"},
+		},
+		{
+			qname: "mail.example.org.",
+			qtype: dns.TypeMX,
+			wantAnswer: []string{"mail.example.org.	300	IN	MX	10 mailserver.example.com."},
+		},
+		{
+			qname: "ptr.example.org.",
+			qtype: dns.TypePTR,
+			wantAnswer: []string{"ptr.example.org.	300	IN	PTR	www.ptr-example.com."},
+		},
+		{
+			qname: "txt.example.org.",
+			qtype: dns.TypeTXT,
+			wantAnswer: []string{"txt.example.org.	300	IN	TXT	\"TXT for example.org\""},
+		},
+	}
+
+	for ti, tc := range tests {
+		req := new(dns.Msg)
+		req.SetQuestion(dns.Fqdn(tc.qname), tc.qtype)
+
+		rec := dnstest.NewRecorder(&test.ResponseWriter{})
+		code, err := demoAzure.ServeDNS(context.Background(), rec, req)
+
+		if err != tc.expectedErr {
+			t.Fatalf("Test %d: Expected error %v, but got %v", ti, tc.expectedErr, err)
+		}
+
+		if code != int(tc.wantRetCode) {
+			t.Fatalf("Test %d: Expected returned status code %s, but got %s", ti, dns.RcodeToString[tc.wantRetCode], dns.RcodeToString[code])
+		}
+
+		if tc.wantMsgRCode != rec.Msg.Rcode {
+			t.Errorf("Test %d: Unexpected msg status code. Want: %s, got: %s", ti, dns.RcodeToString[tc.wantMsgRCode], dns.RcodeToString[rec.Msg.Rcode])
+		}
+
+		if len(tc.wantAnswer) != len(rec.Msg.Answer) {
+			t.Errorf("Test %d: Unexpected number of Answers. Want: %d, got: %d", ti, len(tc.wantAnswer), len(rec.Msg.Answer))
+		} else {
+			for i, gotAnswer := range rec.Msg.Answer {
+				if gotAnswer.String() != tc.wantAnswer[i] {
+					t.Errorf("Test %d: Unexpected answer.\nWant:\n\t%s\nGot:\n\t%s", ti, tc.wantAnswer[i], gotAnswer)
+				}
+			}
+		}
+
+		if len(tc.wantNS) != len(rec.Msg.Ns) {
+			t.Errorf("Test %d: Unexpected NS number. Want: %d, got: %d", ti, len(tc.wantNS), len(rec.Msg.Ns))
+		} else {
+			for i, ns := range rec.Msg.Ns {
+				got, ok := ns.(*dns.SOA)
+				if !ok {
+					t.Errorf("Test %d: Unexpected NS type. Want: SOA, got: %v", ti, reflect.TypeOf(got))
+				}
+				if got.String() != tc.wantNS[i] {
+					t.Errorf("Test %d: Unexpected NS.\nWant: %v\nGot: %v", ti, tc.wantNS[i], got)
+				}
+			}
+		}
+	}
+}