Add Google Cloud DNS plugin (#3011)

Signed-off-by: Palash Nigam <npalash25@gmail.com>

Closes: #2822

1 files changed, 316 insertions, 0 deletions

diff --git a/plugin/clouddns/clouddns_test.go b/plugin/clouddns/clouddns_test.go
new file mode 100644
index 000000000..dafd65bba
--- /dev/null
+++ b/plugin/clouddns/clouddns_test.go
@@ -0,0 +1,316 @@
+package clouddns
+
+import (
+	"context"
+	"errors"
+	"reflect"
+	"testing"
+
+	"github.com/coredns/coredns/plugin/pkg/dnstest"
+	"github.com/coredns/coredns/plugin/pkg/fall"
+	"github.com/coredns/coredns/plugin/pkg/upstream"
+	"github.com/coredns/coredns/plugin/test"
+	crequest "github.com/coredns/coredns/request"
+
+	"github.com/miekg/dns"
+	gcp "google.golang.org/api/dns/v1"
+)
+
+type fakeGCPClient struct {
+	*gcp.Service
+}
+
+func (c fakeGCPClient) zoneExists(projectName, hostedZoneName string) error {
+	return nil
+}
+
+func (c fakeGCPClient) listRRSets(projectName, hostedZoneName string) (*gcp.ResourceRecordSetsListResponse, error) {
+	if projectName == "bad-project" || hostedZoneName == "bad-zone" {
+		return nil, errors.New("the 'parameters.managedZone' resource named 'bad-zone' does not exist")
+	}
+
+	var rr []*gcp.ResourceRecordSet
+
+	if hostedZoneName == "sample-zone-1" {
+		rr = []*gcp.ResourceRecordSet{
+			{
+				Name:    "example.org.",
+				Ttl:     300,
+				Type:    "A",
+				Rrdatas: []string{"1.2.3.4"},
+			},
+			{
+				Name:    "www.example.org",
+				Ttl:     300,
+				Type:    "A",
+				Rrdatas: []string{"1.2.3.4"},
+			},
+			{
+				Name:    "*.www.example.org",
+				Ttl:     300,
+				Type:    "CNAME",
+				Rrdatas: []string{"www.example.org"},
+			},
+			{
+				Name:    "example.org.",
+				Ttl:     300,
+				Type:    "AAAA",
+				Rrdatas: []string{"2001:db8:85a3::8a2e:370:7334"},
+			},
+			{
+				Name:    "sample.example.org",
+				Ttl:     300,
+				Type:    "CNAME",
+				Rrdatas: []string{"example.org"},
+			},
+			{
+				Name:    "example.org.",
+				Ttl:     300,
+				Type:    "PTR",
+				Rrdatas: []string{"ptr.example.org."},
+			},
+			{
+				Name:    "org.",
+				Ttl:     300,
+				Type:    "SOA",
+				Rrdatas: []string{"ns-cloud-c1.googledomains.com. cloud-dns-hostmaster.google.com. 1 21600 300 259200 300"},
+			},
+			{
+				Name:    "com.",
+				Ttl:     300,
+				Type:    "NS",
+				Rrdatas: []string{"ns-cloud-c4.googledomains.com."},
+			},
+			{
+				Name:    "split-example.gov.",
+				Ttl:     300,
+				Type:    "A",
+				Rrdatas: []string{"1.2.3.4"},
+			},
+			{
+				Name:    "swag.",
+				Ttl:     300,
+				Type:    "YOLO",
+				Rrdatas: []string{"foobar"},
+			},
+		}
+	} else {
+		rr = []*gcp.ResourceRecordSet{
+			{
+				Name:    "split-example.org.",
+				Ttl:     300,
+				Type:    "A",
+				Rrdatas: []string{"1.2.3.4"},
+			},
+			{
+				Name:    "other-example.org.",
+				Ttl:     300,
+				Type:    "A",
+				Rrdatas: []string{"3.5.7.9"},
+			},
+			{
+				Name:    "org.",
+				Ttl:     300,
+				Type:    "SOA",
+				Rrdatas: []string{"ns-cloud-e1.googledomains.com. cloud-dns-hostmaster.google.com. 1 21600 300 259200 300"},
+			},
+		}
+	}
+
+	return &gcp.ResourceRecordSetsListResponse{Rrsets: rr}, nil
+}
+
+func TestCloudDNS(t *testing.T) {
+	ctx := context.Background()
+
+	r, err := New(ctx, fakeGCPClient{}, map[string][]string{"bad.": {"bad-project:bad-zone"}}, &upstream.Upstream{})
+	if err != nil {
+		t.Fatalf("Failed to create Cloud DNS: %v", err)
+	}
+	if err = r.Run(ctx); err == nil {
+		t.Fatalf("Expected errors for zone bad.")
+	}
+
+	r, err = New(ctx, fakeGCPClient{}, map[string][]string{"org.": {"sample-project-1:sample-zone-2", "sample-project-1:sample-zone-1"}, "gov.": {"sample-project-1:sample-zone-2", "sample-project-1:sample-zone-1"}}, &upstream.Upstream{})
+	if err != nil {
+		t.Fatalf("Failed to create Cloud DNS: %v", err)
+	}
+	r.Fall = fall.Zero
+	r.Fall.SetZonesFromArgs([]string{"gov."})
+	r.Next = test.HandlerFunc(func(ctx context.Context, w dns.ResponseWriter, r *dns.Msg) (int, error) {
+		state := crequest.Request{W: w, Req: r}
+		qname := state.Name()
+		m := new(dns.Msg)
+		rcode := dns.RcodeServerFailure
+		if qname == "example.gov." {
+			m.SetReply(r)
+			rr, err := dns.NewRR("example.gov.  300 IN  A   2.4.6.8")
+			if err != nil {
+				t.Fatalf("Failed to create Resource Record: %v", err)
+			}
+			m.Answer = []dns.RR{rr}
+
+			m.Authoritative = true
+			rcode = dns.RcodeSuccess
+
+		}
+
+		m.SetRcode(r, rcode)
+		w.WriteMsg(m)
+		return rcode, nil
+	})
+	err = r.Run(ctx)
+	if err != nil {
+		t.Fatalf("Failed to initialize Cloud DNS: %v", err)
+	}
+
+	tests := []struct {
+		qname        string
+		qtype        uint16
+		wantRetCode  int
+		wantAnswer   []string // ownernames for the records in the additional section.
+		wantMsgRCode int
+		wantNS       []string
+		expectedErr  error
+	}{
+		// 0. example.org A found - success.
+		{
+			qname: "example.org",
+			qtype: dns.TypeA,
+			wantAnswer: []string{"example.org.	300	IN	A	1.2.3.4"},
+		},
+		// 1. example.org AAAA found - success.
+		{
+			qname: "example.org",
+			qtype: dns.TypeAAAA,
+			wantAnswer: []string{"example.org.	300	IN	AAAA	2001:db8:85a3::8a2e:370:7334"},
+		},
+		// 2. exampled.org PTR found - success.
+		{
+			qname: "example.org",
+			qtype: dns.TypePTR,
+			wantAnswer: []string{"example.org.	300	IN	PTR	ptr.example.org."},
+		},
+		// 3. sample.example.org points to example.org CNAME.
+		// Query must return both CNAME and A recs.
+		{
+			qname: "sample.example.org",
+			qtype: dns.TypeA,
+			wantAnswer: []string{
+				"sample.example.org.	300	IN	CNAME	example.org.",
+				"example.org.	300	IN	A	1.2.3.4",
+			},
+		},
+		// 4. Explicit CNAME query for sample.example.org.
+		// Query must return just CNAME.
+		{
+			qname: "sample.example.org",
+			qtype: dns.TypeCNAME,
+			wantAnswer: []string{"sample.example.org.	300	IN	CNAME	example.org."},
+		},
+		// 5. Explicit SOA query for example.org.
+		{
+			qname: "example.org",
+			qtype: dns.TypeSOA,
+			wantAnswer: []string{"org.	300	IN	SOA	ns-cloud-e1.googledomains.com. cloud-dns-hostmaster.google.com. 1 21600 300 259200 300"},
+		},
+		// 6. Explicit SOA query for example.org.
+		{
+			qname: "example.org",
+			qtype: dns.TypeNS,
+			wantNS: []string{"org.	300	IN	SOA	ns-cloud-c1.googledomains.com. cloud-dns-hostmaster.google.com. 1 21600 300 259200 300"},
+		},
+		// 7. AAAA query for split-example.org must return NODATA.
+		{
+			qname:       "split-example.gov",
+			qtype:       dns.TypeAAAA,
+			wantRetCode: dns.RcodeSuccess,
+			wantNS: []string{"org.	300	IN	SOA	ns-cloud-c1.googledomains.com. cloud-dns-hostmaster.google.com. 1 21600 300 259200 300"},
+		},
+		// 8. Zone not configured.
+		{
+			qname:        "badexample.com",
+			qtype:        dns.TypeA,
+			wantRetCode:  dns.RcodeServerFailure,
+			wantMsgRCode: dns.RcodeServerFailure,
+		},
+		// 9. No record found. Return SOA record.
+		{
+			qname:        "bad.org",
+			qtype:        dns.TypeA,
+			wantRetCode:  dns.RcodeSuccess,
+			wantMsgRCode: dns.RcodeNameError,
+			wantNS: []string{"org.	300	IN	SOA	ns-cloud-c1.googledomains.com. cloud-dns-hostmaster.google.com. 1 21600 300 259200 300"},
+		},
+		// 10. No record found. Fallthrough.
+		{
+			qname: "example.gov",
+			qtype: dns.TypeA,
+			wantAnswer: []string{"example.gov.	300	IN	A	2.4.6.8"},
+		},
+		// 11. other-zone.example.org is stored in a different hosted zone. success
+		{
+			qname: "other-example.org",
+			qtype: dns.TypeA,
+			wantAnswer: []string{"other-example.org.	300	IN	A	3.5.7.9"},
+		},
+		// 12. split-example.org only has A record. Expect NODATA.
+		{
+			qname: "split-example.org",
+			qtype: dns.TypeAAAA,
+			wantNS: []string{"org.	300	IN	SOA	ns-cloud-e1.googledomains.com. cloud-dns-hostmaster.google.com. 1 21600 300 259200 300"},
+		},
+		// 13. *.www.example.org is a wildcard CNAME to www.example.org.
+		{
+			qname: "a.www.example.org",
+			qtype: dns.TypeA,
+			wantAnswer: []string{
+				"a.www.example.org.	300	IN	CNAME	www.example.org.",
+				"www.example.org.	300	IN	A	1.2.3.4",
+			},
+		},
+	}
+
+	for ti, tc := range tests {
+		req := new(dns.Msg)
+		req.SetQuestion(dns.Fqdn(tc.qname), tc.qtype)
+
+		rec := dnstest.NewRecorder(&test.ResponseWriter{})
+		code, err := r.ServeDNS(ctx, 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)
+				}
+			}
+		}
+	}
+}