oracle: fix detect_openstack to report True on OracleCloud.com DMI data

The OpenStack datasource in 18.3 changed to detect data in the
init-local stage instead of init-network and attempted to redetect
OpenStackLocal datasource on Oracle across reboots. The function
detect_openstack was added to quickly detect whether a platform is
OpenStack based on dmi product_name or chassis_asset_tag and it was
a bit too strict for Oracle in checking for 'OpenStack Nova'/'Compute'
DMI product_name.

Oracle's DMI product_name reports 'SAtandard PC (i440FX + PIIX, 1996)'
and DMI chassis_asset_tag is 'OracleCloud.com'.

detect_openstack function now adds 'OracleCloud.com' as a supported value
'OracleCloud.com' to valid chassis-asset-tags for the OpenStack
datasource.

LP: #1784685

cloudinit/sources/DataSourceOpenStack.py

@@ -28,7 +28,8 @@
 DMI_PRODUCT_COMPUTE = 'OpenStack Compute'
 VALID_DMI_PRODUCT_NAMES = [DMI_PRODUCT_NOVA, DMI_PRODUCT_COMPUTE]
 DMI_ASSET_TAG_OPENTELEKOM = 'OpenTelekomCloud'
-VALID_DMI_ASSET_TAGS = [DMI_ASSET_TAG_OPENTELEKOM]
+DMI_ASSET_TAG_ORACLE_CLOUD = 'OracleCloud.com'
+VALID_DMI_ASSET_TAGS = [DMI_ASSET_TAG_OPENTELEKOM, DMI_ASSET_TAG_ORACLE_CLOUD]
 
 
 class DataSourceOpenStack(openstack.SourceMixin, sources.DataSource):

tests/unittests/test_datasource/test_openstack.py

@@ -510,6 +510,24 @@ def fake_dmi_read(dmi_key):
             ds.detect_openstack(),
             'Expected detect_openstack == True on OpenTelekomCloud')
 
+    @test_helpers.mock.patch(MOCK_PATH + 'util.read_dmi_data')
+    def test_detect_openstack_oraclecloud_chassis_asset_tag(self, m_dmi,
+                                                            m_is_x86):
+        """Return True on OpenStack reporting Oracle cloud asset-tag."""
+        m_is_x86.return_value = True
+
+        def fake_dmi_read(dmi_key):
+            if dmi_key == 'system-product-name':
+                return 'Standard PC (i440FX + PIIX, 1996)'  # No match
+            if dmi_key == 'chassis-asset-tag':
+                return 'OracleCloud.com'
+            assert False, 'Unexpected dmi read of %s' % dmi_key
+
+        m_dmi.side_effect = fake_dmi_read
+        self.assertTrue(
+            ds.detect_openstack(),
+            'Expected detect_openstack == True on OracleCloud.com')
+
     @test_helpers.mock.patch(MOCK_PATH + 'util.get_proc_env')
     @test_helpers.mock.patch(MOCK_PATH + 'util.read_dmi_data')
     def test_detect_openstack_by_proc_1_environ(self, m_dmi, m_proc_env,