azure: introduce identity module (#2116)

- Add query_system_uuid() for getting system uuid from dmi in
normalized (lower-cased) form.

- Add byte_swap_system_uuid() to convert a system uuid for gen1
instances to the compute.vmId as presented by IMDS.

- Add convert_system_uuid_to_vm() to convert system uuid to vm
id depending on whether it is gen1 or gen2.

- Add is_vm_gen1() to determine if VM is Azure's gen1 by checking
for available of EFI (used in gen2).

- Add query_vm_id() helper to get VM id without system uuid.

- Move ChassisAssetTag from Azure helpers into identity.

- Update DataSourceAzure._iid() to use this module.

Signed-off-by: Chris Patterson <cpatterson@microsoft.com>

6 files changed, 310 insertions, 147 deletions

diff --git a/cloudinit/sources/DataSourceAzure.py b/cloudinit/sources/DataSourceAzure.py
index 927e8cf0..aeec6a92 100644
--- a/cloudinit/sources/DataSourceAzure.py
+++ b/cloudinit/sources/DataSourceAzure.py
@@ -16,7 +16,6 @@ from pathlib import Path
 from time import sleep, time
 from typing import Any, Dict, List, Optional
 
-from cloudinit import dmi
 from cloudinit import log as logging
 from cloudinit import net, sources, ssh_util, subp, util
 from cloudinit.event import EventScope, EventType
@@ -27,12 +26,11 @@ from cloudinit.net.dhcp import (
 )
 from cloudinit.net.ephemeral import EphemeralDHCPv4
 from cloudinit.reporting import events
-from cloudinit.sources.azure import imds
+from cloudinit.sources.azure import identity, imds
 from cloudinit.sources.helpers import netlink
 from cloudinit.sources.helpers.azure import (
     DEFAULT_WIRESERVER_ENDPOINT,
     BrokenAzureDataSource,
-    ChassisAssetTag,
     NonAzureDataSource,
     OvfEnvXml,
     azure_ds_reporter,
@@ -43,7 +41,6 @@ from cloudinit.sources.helpers.azure import (
     get_ip_from_lease_value,
     get_metadata_from_fabric,
     get_system_info,
-    is_byte_swapped,
     push_log_to_kvp,
     report_diagnostic_event,
     report_failure_to_fabric,
@@ -695,7 +692,7 @@ class DataSourceAzure(sources.DataSource):
         """Check platform environment to report if this datasource may
         run.
         """
-        chassis_tag = ChassisAssetTag.query_system()
+        chassis_tag = identity.ChassisAssetTag.query_system()
         if chassis_tag is not None:
             return True
 
@@ -857,24 +854,18 @@ class DataSourceAzure(sources.DataSource):
         prev_iid_path = os.path.join(
             self.paths.get_cpath("data"), "instance-id"
         )
-        # Older kernels than 4.15 will have UPPERCASE product_uuid.
-        # We don't want Azure to react to an UPPER/lower difference as a new
-        # instance id as it rewrites SSH host keys.
-        # LP: #1835584
-        system_uuid = dmi.read_dmi_data("system-uuid")
-        if system_uuid is None:
-            raise RuntimeError("failed to read system-uuid")
-
-        iid = system_uuid.lower()
+        system_uuid = identity.query_system_uuid()
         if os.path.exists(prev_iid_path):
             previous = util.load_file(prev_iid_path).strip()
-            if previous.lower() == iid:
-                # If uppercase/lowercase equivalent, return the previous value
-                # to avoid new instance id.
-                return previous
-            if is_byte_swapped(previous.lower(), iid):
+            swapped_id = identity.byte_swap_system_uuid(system_uuid)
+
+            # Older kernels than 4.15 will have UPPERCASE product_uuid.
+            # We don't want Azure to react to an UPPER/lower difference as
+            # a new instance id as it rewrites SSH host keys.
+            # LP: #1835584
+            if previous.lower() in [system_uuid, swapped_id]:
                 return previous
-        return iid
+        return system_uuid
 
     @azure_ds_telemetry_reporter
     def _wait_for_nic_detach(self, nl_sock):
diff --git a/cloudinit/sources/azure/identity.py b/cloudinit/sources/azure/identity.py
new file mode 100644
index 00000000..c371f10c
--- /dev/null
+++ b/cloudinit/sources/azure/identity.py
@@ -0,0 +1,106 @@
+# Copyright (C) 2023 Microsoft Corporation.
+#
+# This file is part of cloud-init. See LICENSE file for license information.
+
+import enum
+import logging
+import os
+import uuid
+from typing import Optional
+
+from cloudinit import dmi
+from cloudinit.sources.helpers.azure import report_diagnostic_event
+
+LOG = logging.getLogger(__name__)
+
+
+def byte_swap_system_uuid(system_uuid: str) -> str:
+    """Byte swap system uuid.
+
+    Azure always uses little-endian for the first three fields in the uuid.
+    This behavior was made strict in SMBIOS 2.6+, but Linux and dmidecode
+    follow RFC 4122 and assume big-endian for earlier SMBIOS versions.
+
+    Azure's gen1 VMs use SMBIOS 2.3 which requires byte swapping to match
+    compute.vmId presented by IMDS.
+
+    Azure's gen2 VMs use SMBIOS 3.1 which does not require byte swapping.
+
+    :raises ValueError: if UUID is invalid.
+    """
+    try:
+        original_uuid = uuid.UUID(system_uuid)
+    except ValueError:
+        msg = f"Failed to parse system uuid: {system_uuid!r}"
+        report_diagnostic_event(msg, logger_func=LOG.error)
+        raise
+
+    return str(uuid.UUID(bytes=original_uuid.bytes_le))
+
+
+def convert_system_uuid_to_vm_id(system_uuid: str) -> str:
+    """Determine VM ID from system uuid."""
+    if is_vm_gen1():
+        return byte_swap_system_uuid(system_uuid)
+
+    return system_uuid
+
+
+def is_vm_gen1() -> bool:
+    """Determine if VM is gen1 or gen2.
+
+    Gen2 guests use UEFI while gen1 is legacy BIOS.
+    """
+    # Linux
+    if os.path.exists("/sys/firmware/efi"):
+        return False
+
+    # BSD
+    if os.path.exists("/dev/efi"):
+        return False
+
+    return True
+
+
+def query_system_uuid() -> str:
+    """Query system uuid in lower-case."""
+    system_uuid = dmi.read_dmi_data("system-uuid")
+    if system_uuid is None:
+        raise RuntimeError("failed to read system-uuid")
+
+    # Kernels older than 4.15 will have upper-case system uuid.
+    system_uuid = system_uuid.lower()
+    LOG.debug("Read product uuid: %s", system_uuid)
+    return system_uuid
+
+
+def query_vm_id() -> str:
+    """Query VM ID from system."""
+    system_uuid = query_system_uuid()
+    return convert_system_uuid_to_vm_id(system_uuid)
+
+
+class ChassisAssetTag(enum.Enum):
+    AZURE_CLOUD = "7783-7084-3265-9085-8269-3286-77"
+
+    @classmethod
+    def query_system(cls) -> Optional["ChassisAssetTag"]:
+        """Check platform environment to report if this datasource may run.
+
+        :returns: ChassisAssetTag if matching tag found, else None.
+        """
+        asset_tag = dmi.read_dmi_data("chassis-asset-tag")
+        try:
+            tag = cls(asset_tag)
+        except ValueError:
+            report_diagnostic_event(
+                "Non-Azure chassis asset tag: %r" % asset_tag,
+                logger_func=LOG.debug,
+            )
+            return None
+
+        report_diagnostic_event(
+            "Azure chassis asset tag: %r (%s)" % (asset_tag, tag.name),
+            logger_func=LOG.debug,
+        )
+        return tag
diff --git a/cloudinit/sources/helpers/azure.py b/cloudinit/sources/helpers/azure.py
index d4fc04e2..c0ffd760 100644
--- a/cloudinit/sources/helpers/azure.py
+++ b/cloudinit/sources/helpers/azure.py
@@ -1,6 +1,5 @@
 # This file is part of cloud-init. See LICENSE file for license information.
 import base64
-import enum
 import json
 import logging
 import os
@@ -17,7 +16,7 @@ from typing import Callable, List, Optional, TypeVar, Union
 from xml.etree import ElementTree
 from xml.sax.saxutils import escape
 
-from cloudinit import distros, dmi, subp, temp_utils, url_helper, util, version
+from cloudinit import distros, subp, temp_utils, url_helper, util, version
 from cloudinit.reporting import events
 from cloudinit.settings import CFG_BUILTIN
 
@@ -65,34 +64,6 @@ def azure_ds_telemetry_reporter(func: Callable[..., T]) -> Callable[..., T]:
     return impl
 
 
-def is_byte_swapped(previous_id, current_id):
-    """
-    Azure stores the instance ID with an incorrect byte ordering for the
-    first parts. This corrects the byte order such that it is consistent with
-    that returned by the metadata service.
-    """
-    if previous_id == current_id:
-        return False
-
-    def swap_bytestring(s, width=2):
-        dd = [byte for byte in textwrap.wrap(s, 2)]
-        dd.reverse()
-        return "".join(dd)
-
-    parts = current_id.split("-")
-    swapped_id = "-".join(
-        [
-            swap_bytestring(parts[0]),
-            swap_bytestring(parts[1]),
-            swap_bytestring(parts[2]),
-            parts[3],
-            parts[4],
-        ]
-    )
-
-    return previous_id == swapped_id
-
-
 @azure_ds_telemetry_reporter
 def get_boot_telemetry():
     """Report timestamps related to kernel initialization and systemd
@@ -1079,32 +1050,6 @@ class NonAzureDataSource(Exception):
     pass
 
 
-class ChassisAssetTag(enum.Enum):
-    AZURE_CLOUD = "7783-7084-3265-9085-8269-3286-77"
-
-    @classmethod
-    def query_system(cls) -> Optional["ChassisAssetTag"]:
-        """Check platform environment to report if this datasource may run.
-
-        :returns: ChassisAssetTag if matching tag found, else None.
-        """
-        asset_tag = dmi.read_dmi_data("chassis-asset-tag")
-        try:
-            tag = cls(asset_tag)
-        except ValueError:
-            report_diagnostic_event(
-                "Non-Azure chassis asset tag: %r" % asset_tag,
-                logger_func=LOG.debug,
-            )
-            return None
-
-        report_diagnostic_event(
-            "Azure chassis asset tag: %r (%s)" % (asset_tag, tag.name),
-            logger_func=LOG.debug,
-        )
-        return tag
-
-
 class OvfEnvXml:
     NAMESPACES = {
         "ovf": "http://schemas.dmtf.org/ovf/environment/1",
diff --git a/tests/unittests/sources/azure/test_identity.py b/tests/unittests/sources/azure/test_identity.py
new file mode 100644
index 00000000..53b1e18f
--- /dev/null
+++ b/tests/unittests/sources/azure/test_identity.py
@@ -0,0 +1,165 @@
+# This file is part of cloud-init. See LICENSE file for license information.
+
+from unittest import mock
+
+import pytest
+
+from cloudinit.sources.azure import identity
+
+
+@pytest.fixture(autouse=True)
+def mock_read_dmi_data():
+    with mock.patch.object(
+        identity.dmi, "read_dmi_data", return_value=None
+    ) as m:
+        yield m
+
+
+@pytest.fixture(autouse=True)
+def mock_os_path_exists():
+    with mock.patch.object(identity.os.path, "exists") as m:
+        yield m
+
+
+class TestByteSwapSystemUuid:
+    @pytest.mark.parametrize(
+        "system_uuid,swapped_uuid",
+        [
+            (
+                "527c2691-029f-fe4c-b1f4-a4da7ebac2cf",
+                "91267c52-9f02-4cfe-b1f4-a4da7ebac2cf",
+            ),
+            (
+                "527C2691-029F-FE4C-B1F4-A4DA7EBAC2CD",
+                "91267c52-9f02-4cfe-b1f4-a4da7ebac2cd",
+            ),
+        ],
+    )
+    def test_values(self, system_uuid, swapped_uuid):
+        assert identity.byte_swap_system_uuid(system_uuid) == swapped_uuid
+
+    @pytest.mark.parametrize(
+        "system_uuid",
+        [
+            "",
+            "g",
+            "91267c52-9f02-4cfe-b1f4-a4da7ebac2c",
+            "91267c52-9f02-4cfe-b1f4-a4da7ebac2ccc",
+            "-----",
+        ],
+    )
+    def test_errors(self, system_uuid):
+        with pytest.raises(ValueError) as exc_info:
+            identity.byte_swap_system_uuid(system_uuid)
+
+        assert exc_info.value.args[0] == "badly formed hexadecimal UUID string"
+
+
+class TestConvertSystemUuidToVmId:
+    def test_gen1(self, monkeypatch):
+        system_uuid = "527c2691-029f-fe4c-b1f4-a4da7ebac2cf"
+        monkeypatch.setattr(identity, "is_vm_gen1", lambda: True)
+
+        swapped_uuid = "91267c52-9f02-4cfe-b1f4-a4da7ebac2cf"
+        assert (
+            identity.convert_system_uuid_to_vm_id(system_uuid) == swapped_uuid
+        )
+
+    def test_gen2(self, monkeypatch):
+        system_uuid = "527c2691-029f-fe4c-b1f4-a4da7ebac2cf"
+        monkeypatch.setattr(identity, "is_vm_gen1", lambda: False)
+
+        assert (
+            identity.convert_system_uuid_to_vm_id(system_uuid) == system_uuid
+        )
+
+
+class TestIsVmGen1:
+    def test_gen1(self, mock_os_path_exists) -> None:
+        mock_os_path_exists.side_effect = lambda _: False
+
+        assert identity.is_vm_gen1() is True
+
+    def test_gen2_freebsd(self, mock_os_path_exists) -> None:
+        mock_os_path_exists.side_effect = lambda x: x == "/dev/efi"
+
+        assert identity.is_vm_gen1() is False
+
+    def test_gen2_linux(self, mock_os_path_exists) -> None:
+        mock_os_path_exists.side_effect = lambda x: x == "/sys/firmware/efi"
+
+        assert identity.is_vm_gen1() is False
+
+
+class TestQuerySystemUuid:
+    @pytest.mark.parametrize(
+        "system_uuid",
+        [
+            "527c2691-029f-fe4c-b1f4-a4da7ebac2cf",
+            "527C2691-029F-FE4C-B1F4-A4DA7EBAC2CF",
+        ],
+    )
+    def test_values(self, mock_read_dmi_data, system_uuid):
+        mock_read_dmi_data.return_value = system_uuid
+
+        assert identity.query_system_uuid() == system_uuid.lower()
+        assert mock_read_dmi_data.mock_calls == [mock.call("system-uuid")]
+
+    def test_errors(self, mock_read_dmi_data):
+        mock_read_dmi_data.return_value = None
+
+        with pytest.raises(RuntimeError) as exc_info:
+            identity.query_system_uuid()
+
+        assert exc_info.value.args[0] == "failed to read system-uuid"
+
+
+class TestQueryVmId:
+    def test_gen1(self, monkeypatch):
+        system_uuid = "527c2691-029f-fe4c-b1f4-a4da7ebac2cf"
+        swapped_uuid = "91267c52-9f02-4cfe-b1f4-a4da7ebac2cf"
+        monkeypatch.setattr(identity, "query_system_uuid", lambda: system_uuid)
+        monkeypatch.setattr(identity, "is_vm_gen1", lambda: True)
+
+        assert identity.query_vm_id() == swapped_uuid
+
+    def test_gen2(self, monkeypatch):
+        system_uuid = "527c2691-029f-fe4c-b1f4-a4da7ebac2cf"
+        monkeypatch.setattr(identity, "query_system_uuid", lambda: system_uuid)
+        monkeypatch.setattr(identity, "is_vm_gen1", lambda: False)
+
+        assert identity.query_vm_id() == system_uuid
+
+
+class TestChassisAssetTag:
+    def test_true_azure_cloud(self, caplog, mock_read_dmi_data):
+        mock_read_dmi_data.return_value = (
+            identity.ChassisAssetTag.AZURE_CLOUD.value
+        )
+
+        asset_tag = identity.ChassisAssetTag.query_system()
+
+        assert asset_tag == identity.ChassisAssetTag.AZURE_CLOUD
+        assert caplog.record_tuples == [
+            (
+                "cloudinit.sources.azure.identity",
+                10,
+                "Azure chassis asset tag: "
+                "'7783-7084-3265-9085-8269-3286-77' (AZURE_CLOUD)",
+            )
+        ]
+
+    @pytest.mark.parametrize("tag", [None, "", "notazure"])
+    def test_false_on_nonazure_chassis(self, caplog, mock_read_dmi_data, tag):
+        mock_read_dmi_data.return_value = tag
+
+        asset_tag = identity.ChassisAssetTag.query_system()
+
+        assert asset_tag is None
+        assert caplog.record_tuples == [
+            (
+                "cloudinit.sources.azure.identity",
+                10,
+                "Non-Azure chassis asset tag: %r" % tag,
+            )
+        ]
diff --git a/tests/unittests/sources/test_azure.py b/tests/unittests/sources/test_azure.py
index 0648f08c..3c36c9c6 100644
--- a/tests/unittests/sources/test_azure.py
+++ b/tests/unittests/sources/test_azure.py
@@ -11,11 +11,12 @@ from pathlib import Path
 import pytest
 import requests
 
-from cloudinit import distros, helpers, subp, url_helper
+from cloudinit import distros, dmi, helpers, subp, url_helper
 from cloudinit.net import dhcp
 from cloudinit.sources import UNSET
 from cloudinit.sources import DataSourceAzure as dsaz
 from cloudinit.sources import InvalidMetaDataException
+from cloudinit.sources.azure import identity
 from cloudinit.sources.helpers import netlink
 from cloudinit.util import (
     MountFailedError,
@@ -81,9 +82,9 @@ def mock_azure_report_failure_to_fabric():
 @pytest.fixture
 def mock_chassis_asset_tag():
     with mock.patch.object(
-        dsaz.ChassisAssetTag,
+        identity.ChassisAssetTag,
         "query_system",
-        return_value=dsaz.ChassisAssetTag.AZURE_CLOUD.value,
+        return_value=identity.ChassisAssetTag.AZURE_CLOUD.value,
     ) as m:
         yield m
 
@@ -110,13 +111,14 @@ def mock_time():
 def mock_dmi_read_dmi_data():
     def fake_read(key: str) -> str:
         if key == "system-uuid":
-            return "fake-system-uuid"
+            return "50109936-ef07-47fe-ac82-890c853f60d5"
         elif key == "chassis-asset-tag":
             return "7783-7084-3265-9085-8269-3286-77"
         raise RuntimeError()
 
-    with mock.patch(
-        MOCKPATH + "dmi.read_dmi_data",
+    with mock.patch.object(
+        dmi,
+        "read_dmi_data",
         side_effect=fake_read,
         autospec=True,
     ) as m:
@@ -1029,7 +1031,7 @@ scbus-1 on xpt0 bus 0
                 ),
                 (dsaz.subp, "which", lambda x: True),
                 (
-                    dsaz.dmi,
+                    dmi,
                     "read_dmi_data",
                     self.m_read_dmi_data,
                 ),
@@ -3147,7 +3149,7 @@ class TestIsPlatformViable:
     @pytest.mark.parametrize(
         "tag",
         [
-            dsaz.ChassisAssetTag.AZURE_CLOUD.value,
+            identity.ChassisAssetTag.AZURE_CLOUD.value,
         ],
     )
     def test_true_on_azure_chassis(
@@ -3422,7 +3424,7 @@ class TestInstanceId:
     def test_fallback(self, azure_ds, mock_dmi_read_dmi_data):
         id = azure_ds.get_instance_id()
 
-        assert id == "fake-system-uuid"
+        assert id == "50109936-ef07-47fe-ac82-890c853f60d5"
 
 
 class TestProvisioning:
@@ -3543,7 +3545,10 @@ class TestProvisioning:
             mock.call("chassis-asset-tag"),
             mock.call("system-uuid"),
         ]
-        assert self.azure_ds.metadata["instance-id"] == "fake-system-uuid"
+        assert (
+            self.azure_ds.metadata["instance-id"]
+            == "50109936-ef07-47fe-ac82-890c853f60d5"
+        )
 
         # Verify IMDS metadata.
         assert self.azure_ds.metadata["imds"] == self.imds_md
@@ -3633,7 +3638,10 @@ class TestProvisioning:
             mock.call("chassis-asset-tag"),
             mock.call("system-uuid"),
         ]
-        assert self.azure_ds.metadata["instance-id"] == "fake-system-uuid"
+        assert (
+            self.azure_ds.metadata["instance-id"]
+            == "50109936-ef07-47fe-ac82-890c853f60d5"
+        )
 
         # Verify IMDS metadata.
         assert self.azure_ds.metadata["imds"] == self.imds_md
@@ -3749,7 +3757,10 @@ class TestProvisioning:
             mock.call("chassis-asset-tag"),
             mock.call("system-uuid"),
         ]
-        assert self.azure_ds.metadata["instance-id"] == "fake-system-uuid"
+        assert (
+            self.azure_ds.metadata["instance-id"]
+            == "50109936-ef07-47fe-ac82-890c853f60d5"
+        )
 
         # Verify IMDS metadata.
         assert self.azure_ds.metadata["imds"] == self.imds_md
@@ -3903,7 +3914,10 @@ class TestProvisioning:
             mock.call("chassis-asset-tag"),
             mock.call("system-uuid"),
         ]
-        assert self.azure_ds.metadata["instance-id"] == "fake-system-uuid"
+        assert (
+            self.azure_ds.metadata["instance-id"]
+            == "50109936-ef07-47fe-ac82-890c853f60d5"
+        )
 
         # Verify IMDS metadata.
         assert self.azure_ds.metadata["imds"] == self.imds_md
diff --git a/tests/unittests/sources/test_azure_helper.py b/tests/unittests/sources/test_azure_helper.py
index 38a57b99..ac2126e8 100644
--- a/tests/unittests/sources/test_azure_helper.py
+++ b/tests/unittests/sources/test_azure_helper.py
@@ -196,28 +196,6 @@ class TestGoalStateParsing(CiTestCase):
         goal_state = self._get_goal_state(instance_id=instance_id)
         self.assertEqual(instance_id, goal_state.instance_id)
 
-    def test_instance_id_byte_swap(self):
-        """Return true when previous_iid is byteswapped current_iid"""
-        previous_iid = "D0DF4C54-4ECB-4A4B-9954-5BDF3ED5C3B8"
-        current_iid = "544CDFD0-CB4E-4B4A-9954-5BDF3ED5C3B8"
-        self.assertTrue(
-            azure_helper.is_byte_swapped(previous_iid, current_iid)
-        )
-
-    def test_instance_id_no_byte_swap_same_instance_id(self):
-        previous_iid = "D0DF4C54-4ECB-4A4B-9954-5BDF3ED5C3B8"
-        current_iid = "D0DF4C54-4ECB-4A4B-9954-5BDF3ED5C3B8"
-        self.assertFalse(
-            azure_helper.is_byte_swapped(previous_iid, current_iid)
-        )
-
-    def test_instance_id_no_byte_swap_diff_instance_id(self):
-        previous_iid = "D0DF4C54-4ECB-4A4B-9954-5BDF3ED5C3B8"
-        current_iid = "G0DF4C54-4ECB-4A4B-9954-5BDF3ED5C3B8"
-        self.assertFalse(
-            azure_helper.is_byte_swapped(previous_iid, current_iid)
-        )
-
     def test_certificates_xml_parsed_and_fetched_correctly(self):
         m_azure_endpoint_client = mock.MagicMock()
         certificates_url = "TestCertificatesUrl"
@@ -1417,42 +1395,6 @@ class TestGetMetadataGoalStateXMLAndReportFailureToFabric(CiTestCase):
         )
 
 
-class TestChassisAssetTag:
-    def test_true_azure_cloud(self, caplog, mock_dmi_read_dmi_data):
-        mock_dmi_read_dmi_data.return_value = (
-            azure_helper.ChassisAssetTag.AZURE_CLOUD.value
-        )
-
-        asset_tag = azure_helper.ChassisAssetTag.query_system()
-
-        assert asset_tag == azure_helper.ChassisAssetTag.AZURE_CLOUD
-        assert caplog.record_tuples == [
-            (
-                "cloudinit.sources.helpers.azure",
-                10,
-                "Azure chassis asset tag: "
-                "'7783-7084-3265-9085-8269-3286-77' (AZURE_CLOUD)",
-            )
-        ]
-
-    @pytest.mark.parametrize("tag", [None, "", "notazure"])
-    def test_false_on_nonazure_chassis(
-        self, caplog, mock_dmi_read_dmi_data, tag
-    ):
-        mock_dmi_read_dmi_data.return_value = tag
-
-        asset_tag = azure_helper.ChassisAssetTag.query_system()
-
-        assert asset_tag is None
-        assert caplog.record_tuples == [
-            (
-                "cloudinit.sources.helpers.azure",
-                10,
-                "Non-Azure chassis asset tag: %r" % tag,
-            )
-        ]
-
-
 class TestOvfEnvXml:
     @pytest.mark.parametrize(
         "ovf,expected",