test: added tests to confirm solution

Author: MoeSalah1999

tests/unittests/net/test_net_freebsd.py

@@ -0,0 +1,126 @@
+# tests/unittests/net/test_net_freebsd.py
+#
+# FreeBSD-specific networking tests
+#
+# These tests validate Azure + FreeBSD edge cases involving
+# duplicate MAC addresses, Hyper-V synthetic NICs (hn*),
+# accelerated VFs (mce*), and deterministic primary NIC selection.
+
+import logging
+from unittest import mock
+
+from cloudinit import net
+
+LOG = logging.getLogger(__name__)
+
+
+@mock.patch("cloudinit.net.util.is_FreeBSD", return_value=True)
+@mock.patch("cloudinit.net.subp.subp")
+def test_freebsd_duplicate_mac_preserves_first_interface(
+    m_subp, _is_freebsd, caplog
+):
+    """Duplicate MACs on FreeBSD must not drop the synthetic hn* NIC.
+
+    Azure exposes hn* (synthetic) and mce* (accelerated VF) interfaces
+    with the same MAC address. The first-discovered interface must be
+    preserved and the duplicate logged.
+    """
+    caplog.set_level(logging.DEBUG)
+
+    def subp_side_effect(cmd, *args, **kwargs):
+        if cmd == ["ifconfig", "-a", "ether"]:
+            return (
+                "\n\n".join(
+                    [
+                        "\n".join(
+                            [
+                                "hn0: flags=8843"
+                                "<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST>",
+                                "\tether aa:bb:cc:dd:ee:ff",
+                            ]
+                        ),
+                        "\n".join(
+                            [
+                                "mce0: flags=8843"
+                                "<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST>",
+                                "\tether aa:bb:cc:dd:ee:ff",
+                            ]
+                        ),
+                    ]
+                ),
+                "",
+            )
+        raise AssertionError(f"Unexpected subp call: {cmd}")
+
+    m_subp.side_effect = subp_side_effect
+
+    interfaces = net.get_interfaces_by_mac_on_freebsd()
+
+    assert "hn0" in interfaces.values()
+    assert "Duplicate MAC" in caplog.text
+
+
+@mock.patch("cloudinit.net.util.is_FreeBSD", return_value=True)
+@mock.patch("cloudinit.net.subp.subp")
+def test_freebsd_get_devicelist_returns_all_interfaces(m_subp, _is_freebsd):
+    """FreeBSD device discovery must not drop interfaces due to MAC collisions.
+
+    get_devicelist() should enumerate all interfaces directly rather than
+    relying on MAC-keyed maps.
+    """
+    m_subp.return_value = ("hn0 mce0 lo0", "")
+
+    devices = net.get_devicelist()
+
+    assert "hn0" in devices
+    assert "mce0" in devices
+    assert "lo0" in devices
+
+
+@mock.patch("cloudinit.net.util.is_FreeBSD", return_value=True)
+def test_freebsd_azure_filters_hyperv_vf_when_synthetic_present(
+    _is_freebsd, caplog
+):
+    """On Azure FreeBSD, accelerated VFs (mce*) must be ignored when a
+    synthetic hn* interface with the same MAC is present.
+    """
+    caplog.set_level(logging.DEBUG)
+
+    interfaces = [
+        ("hn0", "aa:bb:cc:dd:ee:ff", "hn", ""),
+        ("mce0", "aa:bb:cc:dd:ee:ff", "mce", ""),
+    ]
+
+    filtered = list(interfaces)
+
+    net.filter_hyperv_vf_with_synthetic_interface(LOG.debug, filtered)
+
+    names = [iface[0] for iface in filtered]
+
+    assert "hn0" in names
+    assert "mce0" not in names
+
+    assert (
+        "Ignoring 'mce0' VF interface due to synthetic hn interface 'hn0'"
+        in caplog.text
+    )
+
+
+@mock.patch("cloudinit.net.util.is_FreeBSD", return_value=True)
+@mock.patch("cloudinit.net.subp.subp")
+@mock.patch("cloudinit.net.get_interfaces_by_mac")
+def test_freebsd_prefers_hn0_as_primary_interface(
+    m_get_by_mac, m_subp, _is_freebsd
+):
+    m_get_by_mac.return_value = {
+        "aa:aa:aa:aa:aa:01": "mce0",
+        "aa:aa:aa:aa:aa:02": "hn1",
+        "aa:aa:aa:aa:aa:03": "hn0",
+    }
+
+    # Order returned by ifconfig -l -u ether
+    m_subp.return_value = ("mce0 hn1 hn0", "")
+
+    ordered = net.find_candidate_nics_on_freebsd()
+
+    assert ordered[0] == "hn0"