From 1bd33355b0eec4d1169942f7d94e99421b88f5f0 Mon Sep 17 00:00:00 2001
From: Brandon Ewing <brandon.ewing@imc.com>
Date: Fri, 6 Dec 2024 10:24:04 -0600
Subject: [PATCH] Test additional DNS recursion scenarios

Test decrement of recursion counter
Test chained CNAMEs in single answer
Add suppor to bypass name check in FakeDNS handler function

Signed-off-by: Brandon Ewing <brandon.ewing@imc.com>
---
 controllers/utils/dns_test.go | 41 ++++++++++++++++++++++++++++++-----
 controllers/utils/fakedns.go  |  3 ++-
 2 files changed, 38 insertions(+), 6 deletions(-)

diff --git a/controllers/utils/dns_test.go b/controllers/utils/dns_test.go
index f9be1dd49c..0e0d8734db 100644
--- a/controllers/utils/dns_test.go
+++ b/controllers/utils/dns_test.go
@@ -114,14 +114,13 @@ func TestValidDigButMaxRecursion(t *testing.T) {
 		Port: port,
 	}
 	NewFakeDNS(testSettings).
+		AddCNAMERecord("foo.cloud.example.com.", "bar.cloud.example.com.").
 		AddARecord("bar.cloud.example.com.", net.IPv4(10, 1, 0, 3)).
 		Start().
 		RunTestFunc(func() {
-			result, err := Dig("foo.cloud.example.com", 0, testServer)
-			if err != nil {
-				panic(err)
-			}
-			assert.Equal(t, result, []string{})
+			result, err := Dig("foo.cloud.example.com", 1, testServer)
+			assert.Error(t, err)
+			assert.Nil(t, result)
 		})
 
 }
@@ -215,6 +214,12 @@ func TestDigCNAME(t *testing.T) {
 		Host: server,
 		Port: port,
 	}
+	testSettings := FakeDNSSettings{
+		FakeDNSPort:     port,
+		EdgeDNSZoneFQDN: "example.com.",
+		DNSZoneFQDN:     "cloud.example.com.",
+		Dump:            true,
+	}
 	NewFakeDNS(testSettings).
 		AddCNAMERecord("foo.cloud.example.com.", "bar.cloud.example.com.").
 		AddARecord("bar.cloud.example.com.", net.IPv4(10, 1, 0, 3)).
@@ -229,6 +234,32 @@ func TestDigCNAME(t *testing.T) {
 
 }
 
+func TestDigCNAMERecursion(t *testing.T) {
+	testServer := DNSServer{
+		Host: server,
+		Port: port,
+	}
+	testSettings := FakeDNSSettings{
+		FakeDNSPort:     port,
+		EdgeDNSZoneFQDN: "example.com.",
+		DNSZoneFQDN:     "cloud.example.com.",
+		Dump:            true,
+	}
+	NewFakeDNS(testSettings).
+		AddCNAMERecord("foo.cloud.example.com.", "bar.cloud.example.com.").
+		AddCNAMERecord("bar.cloud.example.com.", "baz.cloud.example.com.").
+		AddARecord("baz.cloud.example.com.", net.IPv4(10, 1, 0, 3)).
+		Start().
+		RunTestFunc(func() {
+			result, err := Dig("foo.cloud.example.com", 8, testServer)
+			if err != nil {
+				panic(err)
+			}
+			assert.Equal(t, result, []string{"10.1.0.3"})
+		})
+
+}
+
 func connected() (ok bool) {
 	ctx := context.Background()
 	ctx, cancel := context.WithCancel(ctx)
diff --git a/controllers/utils/fakedns.go b/controllers/utils/fakedns.go
index 72145bffbf..52d3fd79de 100644
--- a/controllers/utils/fakedns.go
+++ b/controllers/utils/fakedns.go
@@ -36,6 +36,7 @@ type FakeDNSSettings struct {
 	FakeDNSPort     int
 	EdgeDNSZoneFQDN string
 	DNSZoneFQDN     string
+	Dump            bool
 }
 
 // DNSMock acts as DNS server but returns mock values
@@ -199,7 +200,7 @@ func (m *DNSMock) handleReflect(w dns.ResponseWriter, r *dns.Msg) {
 	if m.records[r.Question[0].Qtype] != nil {
 		for _, rr := range m.records[r.Question[0].Qtype] {
 			fqdn := strings.Split(rr.String(), "\t")[0]
-			if fqdn == r.Question[0].Name {
+			if fqdn == r.Question[0].Name || m.settings.Dump {
 				msg.Answer = append(msg.Answer, rr)
 			}
 		}