Add ingress-nginx support to dual-stack via overrides

Enable nginx service to use IPv4 and IPv6 on the cluster network.
Update overrides to compute `ipFamilies` from address pools and
set `ipFamilyPolicy: PreferDualStack`, prioritizing the cluster’s
primary pool.

Test Cases:
PASS: build-pkgs.
PASS: On an AIO-SX system with dual stack configured:
      - Running `kubectl describe` for the nginx service pod should
        return both IPv4 and IPv6 on the `IP Family Policy` section.
      - Attaching to a running pod and performing a `nslookup` on
        the nginx service name should return ips for both families.

Closes-Bug: 2109791

Change-Id: I996b8d37a2fa41b85835261e69906a8ed9be5e07
Signed-off-by: Eduardo Almeida <Eduardo.AlmeidadosSantos@windriver.com>

python3-k8sapp-nginx-ingress-controller/k8sapp_nginx_ingress_controller/k8sapp_nginx_ingress_controller/helm/ingress_nginx.py

@@ -7,6 +7,7 @@ from k8sapp_nginx_ingress_controller.common import constants as app_constants
 from oslo_log import log
 from sysinv.common import constants
 from sysinv.common import exception
+from sysinv.common import utils
 from sysinv.helm import base
 
 LOG = log.getLogger(__name__)
@@ -26,17 +27,48 @@ class IngressNginxHelm(base.BaseHelm):
             [app_constants.HELM_NS_NGINX_INGRESS_CONTROLLER]
     }
 
+    ADDR_NAME = utils.format_address_name(
+        constants.CONTROLLER_HOSTNAME,
+        constants.NETWORK_TYPE_OAM)
+
+    def _compute_ip_family_policy(self):
+        """
+        Compute the IP family policy and list of IP families
+        for the service, based on configured address pools.
+
+        Returns a tuple of (policy, ip_families), where:
+        - policy is "PreferDualStack" if both IPv4 and
+          IPv6 pools are present, otherwise "SingleStack".
+        - ip_families is a list of unique families, with the
+          primary pool family first in dual-stack scenarios.
+        """
+        addresses = self.dbapi.address_get_by_name(self.ADDR_NAME)
+        family_map = {4: 'IPv4', 6: 'IPv6'}
+
+        # collect unique families
+        ip_families = {family_map[addr.family] for addr in addresses}
+
+        # Dual-stack: primary first
+        if len(ip_families) > 1:
+            networks = self.dbapi.networks_get_by_type(
+                constants.NETWORK_TYPE_OAM)
+            primary = networks[0].primary_pool_family
+            ip_families.discard(primary)
+            return "PreferDualStack", [primary] + list(ip_families)
+
+        # Single-stack
+        return "SingleStack", list(ip_families)
+
     def get_overrides(self, namespace=None):
         LOG.info("Generating system_overrides for %s chart." % self.CHART)
-        ip_family = "IPv6" if self._is_ipv6_cluster_service() else "IPv4"
 
+        policy, families = self._compute_ip_family_policy()
         overrides = {
             app_constants.HELM_NS_NGINX_INGRESS_CONTROLLER: {
                 'controller': {
                     'service': {
-                        'ipFamilies': [
-                            ip_family
-                        ]
+                        'ipFamilyPolicy': policy,
+                        'ipFamilies': families
                     }
                 },
                 'fullnameOverride': 'ic-nginx-ingress-ingress-nginx'