macs: ignore duplicate MAC for devs with driver driver qmi_wwan (#2090)

Another physical modem which has duplicate MAC addresses.
Cloud-init needs to ignore the subordinate devices which are
associated with the qmi_wwan driver.

Fixes network rendering for the following modems:
Quectel EG25
Quectel RM510Q-GLHA
Sierra Wireless MC7455

LP: #2008888

2 files changed, 29 insertions, 13 deletions

diff --git a/cloudinit/net/__init__.py b/cloudinit/net/__init__.py
index 65d45edf..46bce184 100644
--- a/cloudinit/net/__init__.py
+++ b/cloudinit/net/__init__.py
@@ -1044,7 +1044,7 @@ def get_interfaces_by_mac_on_linux(blacklist_drivers=None) -> dict:
             # cloud-init happens to enumerate network interfaces before drivers
             # have fully initialized the leader/subordinate relationships for
             # those devices or switches.
-            if driver == "mscc_felix" or driver == "fsl_enetc":
+            if driver in ("fsl_enetc", "mscc_felix", "qmi_wwan"):
                 LOG.debug(
                     "Ignoring duplicate macs from '%s' and '%s' due to "
                     "driver '%s'.",
diff --git a/tests/unittests/test_net.py b/tests/unittests/test_net.py
index 832d94fb..d7640d70 100644
--- a/tests/unittests/test_net.py
+++ b/tests/unittests/test_net.py
@@ -8223,23 +8223,39 @@ class TestGetInterfacesByMac(CiTestCase):
         }
         self.assertEqual(expected, result)
 
-    def test_duplicate_ignored_macs(self):
-        # LP: #199792
-        self._data = copy.deepcopy(self._data)
-        self._data["macs"]["swp0"] = "9a:57:7d:78:47:c0"
-        self._data["macs"]["swp1"] = "9a:57:7d:78:47:c0"
-        self._data["own_macs"].append("swp0")
-        self._data["own_macs"].append("swp1")
-        self._data["drivers"]["swp0"] = "mscc_felix"
-        self._data["drivers"]["swp1"] = "mscc_felix"
-        self._mock_setup()
+
+@pytest.mark.parametrize("driver", ("mscc_felix", "fsl_enetc", "qmi_wwan"))
+@mock.patch("cloudinit.net.get_sys_class_path")
+@mock.patch("cloudinit.util.system_info", return_value={"variant": "ubuntu"})
+class TestDuplicateMac:
+    def test_duplicate_ignored_macs(
+        self, _get_system_info, get_sys_class_path, driver, tmpdir, caplog
+    ):
+        # Create sysfs representation of network devices and drivers in tmpdir
+        sys_net_path = tmpdir.join("class/net")
+        get_sys_class_path.return_value = sys_net_path.strpath + "/"
+        net_data = {
+            "swp0/address": "9a:57:7d:78:47:c0",
+            "swp0/addr_assign_type": "0",
+            "swp0/device/dev_id": "something",
+            "swp1/address": "9a:57:7d:78:47:c0",
+            "swp1/addr_assign_type": "0",
+            "swp1/device/dev_id": "something else",
+        }
+        populate_dir(sys_net_path.strpath, net_data)
+        # Symlink for device driver
+        driver_path = tmpdir.join(f"module/{driver}")
+        driver_path.ensure_dir()
+        sys_net_path.join("swp0/device/driver").mksymlinkto(driver_path)
+        sys_net_path.join("swp1/device/driver").mksymlinkto(driver_path)
+
         with does_not_raise():
             net.get_interfaces_by_mac()
         pattern = (
             "Ignoring duplicate macs from 'swp[0-1]' and 'swp[0-1]' due to "
-            "driver 'mscc_felix'."
+            f"driver '{driver}'."
         )
-        assert re.search(pattern, self.logs.getvalue())
+        assert re.search(pattern, caplog.text)
 
 
 class TestInterfacesSorting(CiTestCase):