feat(cloudflare): add support for MX records

docs/sources/mx-record.md

@@ -1,7 +1,7 @@
 # MX record with CRD source
 
 You can create and manage MX records with the help of [CRD source](../sources/crd.md)
-and `DNSEndpoint` CRD. Currently, this feature is only supported by `aws`, `azure`, `google` and `digitalocean` providers.
+and `DNSEndpoint` CRD. Currently, this feature is only supported by `aws`, `azure`, `cloudflare`, `digitalocean` and `google` providers.
 
 In order to start managing MX records you need to set the `--managed-record-types=MX` flag.
 

endpoint/endpoint.go

@@ -71,6 +71,12 @@ func (ttl TTL) IsConfigured() bool {
 // Targets is a representation of a list of targets for an endpoint.
 type Targets []string
 
+// MXTarget represents a single MX (Mail Exchange) record target, including its priority and host.
+type MXTarget struct {
+	priority uint16
+	host     string
+}
+
 // NewTargets is a convenience method to create a new Targets object from a vararg of strings
 func NewTargets(target ...string) Targets {
 	t := make(Targets, 0, len(target))
@@ -394,22 +400,44 @@ func (e *Endpoint) CheckEndpoint() bool {
 	return true
 }
 
+// NewMXRecord parses a string representation of an MX record target (e.g., "10 mail.example.com")
+// and returns an MXTarget struct. Returns an error if the input is invalid.
+func NewMXRecord(target string) (*MXTarget, error) {
+	parts := strings.Fields(strings.TrimSpace(target))
+	if len(parts) != 2 {
+		return nil, fmt.Errorf("invalid MX record target: %s. MX records must have a preference value and a host, e.g. '10 example.com'", target)
+	}
+
+	priority, err := strconv.ParseUint(parts[0], 10, 16)
+	if err != nil {
+		return nil, fmt.Errorf("invalid integer value in target: %s", target)
+	}
+
+	return &MXTarget{
+		priority: uint16(priority),
+		host:     parts[1],
+	}, nil
+}
+
+// GetPriority returns the priority of the MX record target.
+func (m *MXTarget) GetPriority() *uint16 {
+	return &m.priority
+}
+
+// GetHost returns the host of the MX record target.
+func (m *MXTarget) GetHost() *string {
+	return &m.host
+}
+
 func (t Targets) ValidateMXRecord() bool {
 	for _, target := range t {
-		// MX records must have a preference value to indicate priority, e.g. "10 example.com"
-		// as per https://www.rfc-editor.org/rfc/rfc974.txt
-		targetParts := strings.Fields(strings.TrimSpace(target))
-		if len(targetParts) != 2 {
-			log.Debugf("Invalid MX record target: %s. MX records must have a preference value to indicate priority, e.g. '10 example.com'", target)
-			return false
-		}
-		preferenceRaw := targetParts[0]
-		_, err := strconv.ParseUint(preferenceRaw, 10, 16)
+		_, err := NewMXRecord(target)
 		if err != nil {
-			log.Debugf("Invalid SRV record target: %s. Invalid integer value in target.", target)
+			log.Debugf("Invalid MX record target: %s. %v", target, err)
 			return false
 		}
 	}
+
 	return true
 }
 

endpoint/endpoint_test.go

@@ -815,3 +815,113 @@ func TestPDNScheckEndpoint(t *testing.T) {
 		assert.Equal(t, tt.expected, actual)
 	}
 }
+
+func TestNewMXTarget(t *testing.T) {
+	tests := []struct {
+		description string
+		target      string
+		expected    *MXTarget
+		expectError bool
+	}{
+		{
+			description: "Valid MX record",
+			target:      "10 example.com",
+			expected:    &MXTarget{priority: 10, host: "example.com"},
+			expectError: false,
+		},
+		{
+			description: "Invalid MX record with missing priority",
+			target:      "example.com",
+			expectError: true,
+		},
+		{
+			description: "Invalid MX record with non-integer priority",
+			target:      "abc example.com",
+			expectError: true,
+		},
+		{
+			description: "Invalid MX record with too many parts",
+			target:      "10 example.com extra",
+			expectError: true,
+		},
+		{
+			description: "Missing host",
+			target:      "10 ",
+			expected:    nil,
+			expectError: true,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.description, func(t *testing.T) {
+			actual, err := NewMXRecord(tt.target)
+			if tt.expectError {
+				assert.Error(t, err)
+			} else {
+				assert.NoError(t, err)
+				assert.Equal(t, tt.expected, actual)
+			}
+		})
+	}
+}
+
+func TestCheckEndpoint(t *testing.T) {
+	tests := []struct {
+		description string
+		endpoint    Endpoint
+		expected    bool
+	}{
+		{
+			description: "Valid MX record target",
+			endpoint: Endpoint{
+				DNSName:    "example.com",
+				RecordType: RecordTypeMX,
+				Targets:    Targets{"10 example.com"},
+			},
+			expected: true,
+		},
+		{
+			description: "Invalid MX record target",
+			endpoint: Endpoint{
+				DNSName:    "example.com",
+				RecordType: RecordTypeMX,
+				Targets:    Targets{"example.com"},
+			},
+			expected: false,
+		},
+		{
+			description: "Valid SRV record target",
+			endpoint: Endpoint{
+				DNSName:    "_service._tcp.example.com",
+				RecordType: RecordTypeSRV,
+				Targets:    Targets{"10 5 5060 example.com"},
+			},
+			expected: true,
+		},
+		{
+			description: "Invalid SRV record target",
+			endpoint: Endpoint{
+				DNSName:    "_service._tcp.example.com",
+				RecordType: RecordTypeSRV,
+				Targets:    Targets{"10 5 example.com"},
+			},
+			expected: false,
+		},
+		{
+			description: "Non-MX/SRV record type",
+			endpoint: Endpoint{
+				DNSName:    "example.com",
+				RecordType: RecordTypeA,
+				Targets:    Targets{"192.168.1.1"},
+			},
+			expected: true,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.description, func(t *testing.T) {
+			actual := tt.endpoint.CheckEndpoint()
+			assert.Equal(t, tt.expected, actual)
+		})
+	}
+}