[CCLM] Make --network-for-live-migration optional arg (#4053)

##### Short description:
Depending on the clusters' setup, it may not be required to patch the
`liveMigrationConfig` in HCO.
Making it an optional argument.  

##### More details:

##### What this PR does / why we need it:

##### Which issue(s) this PR fixes:

##### Special notes for reviewer:

##### jira-ticket:
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<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit

* **Tests**
* Added an optional CLI option to specify a network name for
cross-cluster live-migration tests. When provided, tests will apply and
use that network; when omitted, network configuration is skipped and
tests proceed without it. The test suite now accepts and honors a
user-supplied network name and handles its absence gracefully.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

Author: jpeimer

conftest.py

@@ -328,6 +328,13 @@ def pytest_addoption(parser):
         "--remote_cluster_password",
         help="Password for the remote cluster for cross-cluster tests",
     )
+    session_group.addoption(
+        "--network-for-live-migration",
+        help=(
+            "Network name for live migration in cross-cluster tests. "
+            "If not provided, HCO's liveMigrationConfig.network will not be set by the tests setup"
+        ),
+    )
 
     # CI group
     ci_group.addoption(

tests/storage/cross_cluster_live_migration/conftest.py

@@ -43,7 +43,16 @@
 
 LOGGER = logging.getLogger(__name__)
 
-LIVE_MIGRATION_NETWORK_NAME = "lm-network"
+
+@pytest.fixture(scope="session")
+def network_for_live_migration_name(request):
+    """
+    Get the network name for live migration from CLI arguments.
+    """
+    network_name = request.session.config.getoption("--network-for-live-migration")
+    if not network_name:
+        LOGGER.info("--network-for-live-migration not provided, skipping network configuration")
+    return network_name
 
 
 @pytest.fixture(scope="session")
@@ -129,19 +138,25 @@ def local_cluster_enabled_feature_gate_and_configured_hco_live_migration_network
 
 
 @pytest.fixture(scope="package")
-def local_cluster_network_for_live_migration(admin_client, hco_namespace):
+def local_cluster_network_for_live_migration(admin_client, hco_namespace, network_for_live_migration_name):
+    if not network_for_live_migration_name:
+        return None
     return NetworkAttachmentDefinition(
-        name=LIVE_MIGRATION_NETWORK_NAME,
+        name=network_for_live_migration_name,
         namespace=hco_namespace.name,
         client=admin_client,
         ensure_exists=True,
     )
 
 
 @pytest.fixture(scope="package")
-def remote_cluster_network_for_live_migration(remote_admin_client, remote_cluster_hco_namespace):
+def remote_cluster_network_for_live_migration(
+    remote_admin_client, remote_cluster_hco_namespace, network_for_live_migration_name
+):
+    if not network_for_live_migration_name:
+        return None
     return NetworkAttachmentDefinition(
-        name=LIVE_MIGRATION_NETWORK_NAME,
+        name=network_for_live_migration_name,
         namespace=remote_cluster_hco_namespace.name,
         client=remote_admin_client,
         ensure_exists=True,

tests/storage/cross_cluster_live_migration/utils.py

@@ -1,3 +1,4 @@
+import logging
 from typing import Generator
 
 from kubernetes.dynamic import DynamicClient
@@ -11,59 +12,65 @@
 from utilities.infra import get_daemonset_by_name
 from utilities.virt import VirtualMachineForTests, migrate_vm_and_verify, wait_for_virt_handler_pods_network_updated
 
+LOGGER = logging.getLogger(__name__)
+
 
 def enable_feature_gate_and_configure_hco_live_migration_network(
     hyperconverged_resource: HyperConverged,
     client: DynamicClient,
-    network_for_live_migration: NetworkAttachmentDefinition,
     hco_namespace: Namespace,
+    network_for_live_migration: NetworkAttachmentDefinition | None = None,
 ) -> Generator[None, None, None]:
     """
-    Enable decentralized live migration feature gate and configure HCO live migration network.
+    Enable decentralized live migration feature gate and optionally configure HCO live migration network.
 
     Args:
         hyperconverged_resource: The HyperConverged resource to patch
         client: The DynamicClient for the cluster
-        network_for_live_migration: The NetworkAttachmentDefinition for live migration
         hco_namespace: The HCO namespace
+        network_for_live_migration: The NetworkAttachmentDefinition for live migration,
+            or None to skip network configuration
 
     Yields:
         None
     """
-    virt_handler_daemonset = get_daemonset_by_name(
-        admin_client=client,
-        daemonset_name=VIRT_HANDLER,
-        namespace_name=hco_namespace.name,
-    )
+    spec_patch = {"featureGates": {"decentralizedLiveMigration": True}}
+
+    # Only configure network if provided
+    virt_handler_daemonset = None
+    if network_for_live_migration:
+        LOGGER.info("Adding live migration network configuration to HCO spec patch")
+        spec_patch["liveMigrationConfig"] = {"network": network_for_live_migration.name}
+
+        virt_handler_daemonset = get_daemonset_by_name(
+            admin_client=client,
+            daemonset_name=VIRT_HANDLER,
+            namespace_name=hco_namespace.name,
+        )
 
     with ResourceEditorValidateHCOReconcile(
-        patches={
-            hyperconverged_resource: {
-                "spec": {
-                    "featureGates": {"decentralizedLiveMigration": True},
-                    "liveMigrationConfig": {"network": network_for_live_migration.name},
-                }
-            }
-        },
+        patches={hyperconverged_resource: {"spec": spec_patch}},
         list_resource_reconcile=[KubeVirt],
         wait_for_reconcile_post_update=True,
         admin_client=client,
     ):
+        if network_for_live_migration and virt_handler_daemonset:
+            wait_for_virt_handler_pods_network_updated(
+                client=client,
+                namespace=hco_namespace,
+                network_name=network_for_live_migration.name,
+                virt_handler_daemonset=virt_handler_daemonset,
+            )
+        yield
+
+    if network_for_live_migration and virt_handler_daemonset:
         wait_for_virt_handler_pods_network_updated(
             client=client,
             namespace=hco_namespace,
             network_name=network_for_live_migration.name,
             virt_handler_daemonset=virt_handler_daemonset,
+            migration_network=False,
         )
-        yield
-
-    wait_for_virt_handler_pods_network_updated(
-        client=client,
-        namespace=hco_namespace,
-        network_name=network_for_live_migration.name,
-        virt_handler_daemonset=virt_handler_daemonset,
-        migration_network=False,
-    )
 
 
 def verify_compute_live_migration_after_cclm(