Fix MetalLB L2Advertisement to use baremetal network interface only

Author: zhfeng

ci-operator/step-registry/hypershift/kubevirt/baremetalds/metallb/hypershift-kubevirt-baremetalds-metallb-commands.sh

@@ -5,6 +5,23 @@ set -o errexit
 set -o pipefail
 set -x
 
+POOL_RANGE="192.168.111.30-192.168.111.50"
+
+# Pin L2 announcements to the baremetal network interface only.
+# Without this, extra network interfaces (e.g. from nmstate) can cause
+# MetalLB speakers to announce VIPs on the wrong interface, making
+# LoadBalancer IPs unreachable from the infra cluster.
+# In OVN environments the baremetal network (192.168.111.0/24) lives on
+# br-ex (OVS external bridge). With OpenShiftSDN the raw NIC keeps the
+# IP directly. Detect the network type and choose accordingly.
+NETWORK_TYPE=$(oc get network.config cluster -o jsonpath='{.status.networkType}')
+if [[ "${NETWORK_TYPE}" == "OVNKubernetes" ]]; then
+  METALLB_IFACE="br-ex"
+else
+  METALLB_IFACE="enp2s0"
+fi
+echo "Detected network type ${NETWORK_TYPE}, using interface ${METALLB_IFACE} for L2 advertisements"
+
 oc create -f - <<EOF
 apiVersion: metallb.io/v1beta1
 kind: MetalLB
@@ -21,7 +38,7 @@ metadata:
   namespace: metallb-system
 spec:
   addresses:
-  - 192.168.111.30-192.168.111.50
+  - ${POOL_RANGE}
 EOF
 
 oc create -f - <<EOF
@@ -33,4 +50,6 @@ metadata:
 spec:
   ipAddressPools:
    - metallb
+  interfaces:
+   - ${METALLB_IFACE}
 EOF