sources/azure: do not persist failed_desired_api_version flag (#1159)

If get_imds_data_with_api_fallback() falls back to the minimum required
API version, it is effectively pinned to the old API version forever.

Remove the failed_desired_api_version property to prevent persistence of
the flag between calls and/or reboots.

The continued presence of this flag in obj.pkl should be harmless.

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

2 files changed, 45 insertions, 27 deletions

diff --git a/cloudinit/sources/DataSourceAzure.py b/cloudinit/sources/DataSourceAzure.py
index a8b403e8..f5630840 100755
--- a/cloudinit/sources/DataSourceAzure.py
+++ b/cloudinit/sources/DataSourceAzure.py
@@ -297,13 +297,10 @@ class DataSourceAzure(sources.DataSource):
         self.dhclient_lease_file = self.ds_cfg.get("dhclient_lease_file")
         self._network_config = None
         self._ephemeral_dhcp_ctx = None
-        self.failed_desired_api_version = False
         self.iso_dev = None
 
     def _unpickle(self, ci_pkl_version: int) -> None:
         super()._unpickle(ci_pkl_version)
-        if not hasattr(self, "failed_desired_api_version"):
-            self.failed_desired_api_version = False
         if not hasattr(self, "iso_dev"):
             self.iso_dev = None
 
@@ -647,29 +644,24 @@ class DataSourceAzure(sources.DataSource):
         this fault tolerant and fall back to a good known minimum api
         version.
         """
-
-        if not self.failed_desired_api_version:
-            for _ in range(retries):
-                try:
-                    LOG.info("Attempting IMDS api-version: %s", IMDS_VER_WANT)
-                    return get_metadata_from_imds(
-                        fallback_nic=fallback_nic,
-                        retries=0,
-                        md_type=md_type,
-                        api_version=IMDS_VER_WANT,
-                        exc_cb=exc_cb,
-                    )
-                except UrlError as err:
-                    LOG.info(
-                        "UrlError with IMDS api-version: %s", IMDS_VER_WANT
+        for _ in range(retries):
+            try:
+                LOG.info("Attempting IMDS api-version: %s", IMDS_VER_WANT)
+                return get_metadata_from_imds(
+                    fallback_nic=fallback_nic,
+                    retries=0,
+                    md_type=md_type,
+                    api_version=IMDS_VER_WANT,
+                    exc_cb=exc_cb,
+                )
+            except UrlError as err:
+                LOG.info("UrlError with IMDS api-version: %s", IMDS_VER_WANT)
+                if err.code == 400:
+                    log_msg = "Fall back to IMDS api-version: {}".format(
+                        IMDS_VER_MIN
                     )
-                    if err.code == 400:
-                        log_msg = "Fall back to IMDS api-version: {}".format(
-                            IMDS_VER_MIN
-                        )
-                        report_diagnostic_event(log_msg, logger_func=LOG.info)
-                        self.failed_desired_api_version = True
-                        break
+                    report_diagnostic_event(log_msg, logger_func=LOG.info)
+                    break
 
         LOG.info("Using IMDS api-version: %s", IMDS_VER_MIN)
         return get_metadata_from_imds(
diff --git a/tests/unittests/sources/test_azure.py b/tests/unittests/sources/test_azure.py
index 8b0762b7..44c0a545 100644
--- a/tests/unittests/sources/test_azure.py
+++ b/tests/unittests/sources/test_azure.py
@@ -2149,7 +2149,24 @@ scbus-1 on xpt0 bus 0
         dsrc = self._get_ds(data)
         dsrc.get_data()
         self.assertIsNotNone(dsrc.metadata)
-        self.assertTrue(dsrc.failed_desired_api_version)
+
+        assert m_get_metadata_from_imds.mock_calls == [
+            mock.call(
+                fallback_nic="eth9",
+                retries=0,
+                md_type=dsaz.metadata_type.all,
+                api_version="2021-08-01",
+                exc_cb=mock.ANY,
+            ),
+            mock.call(
+                fallback_nic="eth9",
+                retries=10,
+                md_type=dsaz.metadata_type.all,
+                api_version="2019-06-01",
+                exc_cb=mock.ANY,
+                infinite=False,
+            ),
+        ]
 
     @mock.patch(
         MOCKPATH + "get_metadata_from_imds", return_value=NETWORK_METADATA
@@ -2164,7 +2181,16 @@ scbus-1 on xpt0 bus 0
         dsrc = self._get_ds(data)
         dsrc.get_data()
         self.assertIsNotNone(dsrc.metadata)
-        self.assertFalse(dsrc.failed_desired_api_version)
+
+        assert m_get_metadata_from_imds.mock_calls == [
+            mock.call(
+                fallback_nic="eth9",
+                retries=0,
+                md_type=dsaz.metadata_type.all,
+                api_version="2021-08-01",
+                exc_cb=mock.ANY,
+            )
+        ]
 
     @mock.patch(MOCKPATH + "get_metadata_from_imds")
     def test_hostname_from_imds(self, m_get_metadata_from_imds):