Put srv in backup is not in zone

pkg/service/endpoints.go

@@ -23,6 +23,7 @@ import (
 	"github.com/haproxytech/kubernetes-ingress/pkg/annotations"
 	"github.com/haproxytech/kubernetes-ingress/pkg/haproxy/api"
 	"github.com/haproxytech/kubernetes-ingress/pkg/store"
+	"github.com/haproxytech/kubernetes-ingress/pkg/zone"
 )
 
 // HandleHAProxySrvs handles the haproxy backend servers of the corresponding IngressPath (service + port)
@@ -69,6 +70,10 @@ func (s *Service) updateHAProxySrv(client api.HAProxyClient, srvSlot store.HAPro
 	if srvSlot.Address != "" {
 		srv.Address = srvSlot.Address
 		srv.Maintenance = "disabled"
+		// Put in backup if cross zone traffic is disabled
+		if zone.IsBackupEnabledForThisIP(srv.Address) {
+			srv.Backup = "enabled"
+		}
 	}
 	logger.Tracef("[CONFIG] [BACKEND] [SERVER] backend %s: about to update server in configuration file :  models.Server { Name: %s, Port: %d, Address: %s, Maintenance: %s }", s.backend.Name, srv.Name, *srv.Port, srv.Address, srv.Maintenance)
 	// Update server

pkg/zone/zone.go

@@ -0,0 +1,76 @@
+package zone
+
+import (
+	"fmt"
+	"net"
+	"os"
+	"strings"
+)
+
+var controllerIP string
+var controllerZone string
+var zonesInfo string
+var zonesCrossEnabled bool = true
+
+func init() {
+	controllerIP = os.Getenv("POD_IP")
+	zonesInfo = os.Getenv("ZONES_INFO")
+	zonesCrossEnabled = !(strings.ToLower(os.Getenv("ZONES_CROSS_TRAFFIC_ENABLED")) == "false")
+
+	if controllerIP == "" || zonesInfo == "" {
+		zonesCrossEnabled = true
+		return
+	}
+
+	controllerZone = getZoneFromIP(controllerIP, zonesInfo)
+}
+
+// This function is used when haproxy configure a server in backend
+func IsBackupEnabledForThisIP(address string) bool {
+	if zonesCrossEnabled || address == "" || address == "127.0.0.1" {
+		return false
+	}
+	srvZone := getZoneFromIP(address, zonesInfo)
+	return srvZone != controllerZone
+}
+
+// Private; Auxiliary functions
+func getZoneFromIP(address string, zoneSubnets string) string {
+	input := strings.ReplaceAll(zoneSubnets, " ", "")
+	subnetGroups := strings.Split(input, ";")
+
+	for _, group := range subnetGroups {
+		parts := strings.Split(group, ":")
+		if len(parts) != 2 || parts[1] == "" {
+			return "unknown"
+		}
+
+		zoneName := parts[0]
+		subnets := strings.Split(parts[1], ",")
+
+		for _, subnet := range subnets {
+			if ok, _ := isIPInSubnet(address, subnet); ok {
+				return zoneName
+			}
+		}
+	}
+
+	return "unknown"
+}
+
+func isIPInSubnet(ipStr, subnetStr string) (bool, error) {
+	// Parseamos la IP
+	ip := net.ParseIP(ipStr)
+	if ip == nil {
+		return false, fmt.Errorf("IP inválida: %s", ipStr)
+	}
+
+	// Parseamos la subnet (dirección IP + máscara)
+	_, subnet, err := net.ParseCIDR(subnetStr)
+	if err != nil {
+		return false, fmt.Errorf("subred inválida: %s", subnetStr)
+	}
+
+	// Comprobamos si la IP está dentro de la subred
+	return subnet.Contains(ip), nil
+}

pkg/zone/zone_test.go

@@ -0,0 +1,66 @@
+package zone
+
+import (
+	"testing"
+)
+
+func TestGetZoneFromIp(t *testing.T) {
+	tests := []struct {
+		name        string
+		address     string
+		zoneSubnets string
+		expected    string
+	}{
+		{
+			name:        "IP belongs to eu-south-2a",
+			address:     "192.168.2.1",
+			zoneSubnets: "eu-south-2a: 192.168.1.0/24, 192.168.2.0/24; eu-south-2b: 192.168.3.0/24",
+			expected:    "eu-south-2a",
+		},
+		{
+			name:        "IP belongs to eu-south-2b",
+			address:     "192.168.3.10",
+			zoneSubnets: "eu-south-2a: 192.168.1.0/24, 192.168.2.0/24; eu-south-2b: 192.168.3.0/24",
+			expected:    "eu-south-2b",
+		},
+		{
+			name:        "IP not in any subnet",
+			address:     "10.0.0.1",
+			zoneSubnets: "eu-south-2a: 192.168.1.0/24, 192.168.2.0/24; eu-south-2b: 192.168.3.0/24",
+			expected:    "unknown",
+		},
+		{
+			name:        "Malformed input - no subnet",
+			address:     "192.168.2.1",
+			zoneSubnets: "eu-south-2a:;eu-south-2b:192.168.2.0/24",
+			expected:    "unknown",
+		},
+		{
+			name:        "Malformed input - no subnet",
+			address:     "192.168.2.1",
+			zoneSubnets: "eu-south-2a;eu-south-2b:192.168.2.0/24",
+			expected:    "unknown",
+		},
+		{
+			name:        "IP belongs to overlapping subnets, first match",
+			address:     "192.167.4.10",
+			zoneSubnets: "eu-south-2a:192.167.4.0/24;eu-south-2b:192.167.4.0/16",
+			expected:    "eu-south-2a",
+		},
+		{
+			name:        "Empty Data",
+			address:     "192.167.4.10",
+			zoneSubnets: "   ",
+			expected:    "unknown",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			result := getZoneFromIP(tt.address, tt.zoneSubnets)
+			if result != tt.expected {
+				t.Errorf("expected %s, got %s", tt.expected, result)
+			}
+		})
+	}
+}