Decrease azure ephemeral resource disk wait time

cloudinit/sources/DataSourceAzure.py

@@ -270,7 +270,7 @@ def get_resource_disk_on_freebsd(port_id):
 }
 # RELEASE_BLOCKER: Xenial and earlier apply_network_config default is False
 
-BUILTIN_CLOUD_CONFIG = {
+BUILTIN_CLOUD_EPHEMERAL_DISK_CONFIG = {
     'disk_setup': {
         'ephemeral0': {'table_type': 'gpt',
                        'layout': [100],
@@ -618,8 +618,26 @@ def _get_data(self):
             maybe_remove_ubuntu_network_config_scripts()
 
         # Process crawled data and augment with various config defaults
-        self.cfg = util.mergemanydict(
-            [crawled_data['cfg'], BUILTIN_CLOUD_CONFIG])
+
+        # Only merge in default cloud config related to the ephemeral disk
+        # if the ephemeral disk exists
+        devpath = RESOURCE_DISK_PATH
+        if os.path.exists(devpath):
+            report_diagnostic_event(
+                "Ephemeral resource disk '%s' exists. "
+                "Merging default Azure cloud ephemeral disk configs."
+                % devpath,
+                logger_func=LOG.debug)
+            self.cfg = util.mergemanydict(
+                [crawled_data['cfg'], BUILTIN_CLOUD_EPHEMERAL_DISK_CONFIG])
+        else:
+            report_diagnostic_event(
+                "Ephemeral resource disk '%s' does not exist. "
+                "Not merging default Azure cloud ephemeral disk configs."
+                % devpath,
+                logger_func=LOG.debug)
+            self.cfg = crawled_data['cfg']
+
         self._metadata_imds = crawled_data['metadata']['imds']
         self.metadata = util.mergemanydict(
             [crawled_data['metadata'], DEFAULT_METADATA])
@@ -1468,26 +1486,17 @@ def count_files(mp):
 
 
 @azure_ds_telemetry_reporter
-def address_ephemeral_resize(devpath=RESOURCE_DISK_PATH, maxwait=120,
+def address_ephemeral_resize(devpath=RESOURCE_DISK_PATH,
                              is_new_instance=False, preserve_ntfs=False):
-    # wait for ephemeral disk to come up
-    naplen = .2
-    with events.ReportEventStack(
-        name="wait-for-ephemeral-disk",
-        description="wait for ephemeral disk",
-        parent=azure_ds_reporter
-    ):
-        missing = util.wait_for_files([devpath],
-                                      maxwait=maxwait,
-                                      naplen=naplen,
-                                      log_pre="Azure ephemeral disk: ")
-
-        if missing:
-            report_diagnostic_event(
-                "ephemeral device '%s' did not appear after %d seconds." %
-                (devpath, maxwait),
-                logger_func=LOG.warning)
-            return
+    if not os.path.exists(devpath):
+        report_diagnostic_event(
+            "Ephemeral resource disk '%s' does not exist." % devpath,
+            logger_func=LOG.debug)
+        return
+    else:
+        report_diagnostic_event(
+            "Ephemeral resource disk '%s' exists." % devpath,
+            logger_func=LOG.debug)
 
     result = False
     msg = None

integration-requirements.txt

@@ -1,5 +1,5 @@
 # PyPI requirements for cloud-init integration testing
 # https://cloudinit.readthedocs.io/en/latest/topics/integration_tests.html
 #
-pycloudlib @ git+https://github.com/canonical/pycloudlib.git@3a6c668fed769f00d83d1e6bea7d68953787cc38
+pycloudlib @ git+https://github.com/canonical/pycloudlib.git@da8445325875674394ffd85aaefaa3d2d0e0020d
 pytest

tests/integration_tests/bugs/test_lp1901011.py

@@ -0,0 +1,58 @@
+"""Integration test for LP: #1901011
+
+Ensure an ephemeral disk exists after boot.
+
+See https://github.com/canonical/cloud-init/pull/800
+"""
+import pytest
+
+from tests.integration_tests.clouds import IntegrationCloud
+
+
+@pytest.mark.azure
+@pytest.mark.parametrize('instance_type,is_ephemeral', [
+    ('Standard_DS1_v2', True),
+    ('Standard_D2s_v4', False),
+])
+def test_ephemeral(instance_type, is_ephemeral,
+                   session_cloud: IntegrationCloud, setup_image):
+    if is_ephemeral:
+        expected_log = (
+            "Ephemeral resource disk '/dev/disk/cloud/azure_resource' exists. "
+            "Merging default Azure cloud ephemeral disk configs."
+        )
+    else:
+        expected_log = (
+            "Ephemeral resource disk '/dev/disk/cloud/azure_resource' does "
+            "not exist. Not merging default Azure cloud ephemeral disk "
+            "configs."
+        )
+
+    with session_cloud.launch(
+        launch_kwargs={'instance_type': instance_type}
+    ) as client:
+        # Verify log file
+        log = client.read_from_file('/var/log/cloud-init.log')
+        assert expected_log in log
+
+        # Verify devices
+        dev_links = client.execute('ls /dev/disk/cloud')
+        assert 'azure_root' in dev_links
+        assert 'azure_root-part1' in dev_links
+        if is_ephemeral:
+            assert 'azure_resource' in dev_links
+            assert 'azure_resource-part1' in dev_links
+
+        # Verify mounts
+        blks = client.execute('lsblk -pPo NAME,TYPE,MOUNTPOINT')
+        root_device = client.execute(
+            'realpath /dev/disk/cloud/azure_root-part1'
+        )
+        assert 'NAME="{}" TYPE="part" MOUNTPOINT="/"'.format(
+            root_device) in blks
+        if is_ephemeral:
+            ephemeral_device = client.execute(
+                'realpath /dev/disk/cloud/azure_resource-part1'
+            )
+            assert 'NAME="{}" TYPE="part" MOUNTPOINT="/mnt"'.format(
+                ephemeral_device) in blks

tests/unittests/test_datasource/test_azure.py

@@ -1354,23 +1354,51 @@ def test_cfg_has_no_fingerprint_has_value(self):
         for mypk in mypklist:
             self.assertIn(mypk['value'], dsrc.metadata['public-keys'])
 
-    def test_default_ephemeral(self):
-        # make sure the ephemeral device works
+    def test_default_ephemeral_configs_ephemeral_exists(self):
+        # make sure the ephemeral configs are correct if disk present
         odata = {}
         data = {'ovfcontent': construct_valid_ovf_env(data=odata),
                 'sys_cfg': {}}
 
-        dsrc = self._get_ds(data)
-        ret = dsrc.get_data()
-        self.assertTrue(ret)
-        cfg = dsrc.get_config_obj()
+        orig_exists = dsaz.os.path.exists
+
+        def changed_exists(path):
+            return True if path == dsaz.RESOURCE_DISK_PATH else orig_exists(
+                path)
+
+        with mock.patch(MOCKPATH + 'os.path.exists', new=changed_exists):
+            dsrc = self._get_ds(data)
+            ret = dsrc.get_data()
+            self.assertTrue(ret)
+            cfg = dsrc.get_config_obj()
+
+            self.assertEqual(dsrc.device_name_to_device("ephemeral0"),
+                             dsaz.RESOURCE_DISK_PATH)
+            assert 'disk_setup' in cfg
+            assert 'fs_setup' in cfg
+            self.assertIsInstance(cfg['disk_setup'], dict)
+            self.assertIsInstance(cfg['fs_setup'], list)
+
+    def test_default_ephemeral_configs_ephemeral_does_not_exist(self):
+        # make sure the ephemeral configs are correct if disk not present
+        odata = {}
+        data = {'ovfcontent': construct_valid_ovf_env(data=odata),
+                'sys_cfg': {}}
+
+        orig_exists = dsaz.os.path.exists
+
+        def changed_exists(path):
+            return False if path == dsaz.RESOURCE_DISK_PATH else orig_exists(
+                path)
+
+        with mock.patch(MOCKPATH + 'os.path.exists', new=changed_exists):
+            dsrc = self._get_ds(data)
+            ret = dsrc.get_data()
+            self.assertTrue(ret)
+            cfg = dsrc.get_config_obj()
 
-        self.assertEqual(dsrc.device_name_to_device("ephemeral0"),
-                         dsaz.RESOURCE_DISK_PATH)
-        assert 'disk_setup' in cfg
-        assert 'fs_setup' in cfg
-        self.assertIsInstance(cfg['disk_setup'], dict)
-        self.assertIsInstance(cfg['fs_setup'], list)
+            assert 'disk_setup' not in cfg
+            assert 'fs_setup' not in cfg
 
     def test_provide_disk_aliases(self):
         # Make sure that user can affect disk aliases