From 133ad2cb327ad17b7b81319fac8f9f14577c04df Mon Sep 17 00:00:00 2001 From: Chad Smith Date: Wed, 14 Mar 2018 23:38:07 -0600 Subject: set_hostname: When present in metadata, set it before network bringup. When instance meta-data provides hostname information, run cc_set_hostname in the init-local or init-net stage before network comes up. Prevent an initial DHCP request which leaks the stock cloud-image default hostname before the meta-data provided hostname was processed. A leaked cloud-image hostname adversely affects Dynamic DNS which would reallocate 'ubuntu' hostname in DNS to every instance brought up by cloud-init. These instances would only update DNS to the cloud-init configured hostname upon DHCP lease renewal. This branch extends the get_hostname methods in datasource, cloud and util to limit results to metadata_only to avoid extra cost of querying the distro for hostname information if metadata does not provide that information. LP: #1746455 --- cloudinit/sources/tests/test_init.py | 70 +++++++++++++++++++++++++++++++++++- 1 file changed, 69 insertions(+), 1 deletion(-) (limited to 'cloudinit/sources/tests/test_init.py') diff --git a/cloudinit/sources/tests/test_init.py b/cloudinit/sources/tests/test_init.py index af151154..5065083c 100644 --- a/cloudinit/sources/tests/test_init.py +++ b/cloudinit/sources/tests/test_init.py @@ -7,7 +7,7 @@ import stat from cloudinit.helpers import Paths from cloudinit.sources import ( INSTANCE_JSON_FILE, DataSource) -from cloudinit.tests.helpers import CiTestCase, skipIf +from cloudinit.tests.helpers import CiTestCase, skipIf, mock from cloudinit.user_data import UserDataProcessor from cloudinit import util @@ -108,6 +108,74 @@ class TestDataSource(CiTestCase): self.assertEqual('userdata_raw', datasource.userdata_raw) self.assertEqual('vendordata_raw', datasource.vendordata_raw) + def test_get_hostname_strips_local_hostname_without_domain(self): + """Datasource.get_hostname strips metadata local-hostname of domain.""" + tmp = self.tmp_dir() + datasource = DataSourceTestSubclassNet( + self.sys_cfg, self.distro, Paths({'run_dir': tmp})) + self.assertTrue(datasource.get_data()) + self.assertEqual( + 'test-subclass-hostname', datasource.metadata['local-hostname']) + self.assertEqual('test-subclass-hostname', datasource.get_hostname()) + datasource.metadata['local-hostname'] = 'hostname.my.domain.com' + self.assertEqual('hostname', datasource.get_hostname()) + + def test_get_hostname_with_fqdn_returns_local_hostname_with_domain(self): + """Datasource.get_hostname with fqdn set gets qualified hostname.""" + tmp = self.tmp_dir() + datasource = DataSourceTestSubclassNet( + self.sys_cfg, self.distro, Paths({'run_dir': tmp})) + self.assertTrue(datasource.get_data()) + datasource.metadata['local-hostname'] = 'hostname.my.domain.com' + self.assertEqual( + 'hostname.my.domain.com', datasource.get_hostname(fqdn=True)) + + def test_get_hostname_without_metadata_uses_system_hostname(self): + """Datasource.gethostname runs util.get_hostname when no metadata.""" + tmp = self.tmp_dir() + datasource = DataSourceTestSubclassNet( + self.sys_cfg, self.distro, Paths({'run_dir': tmp})) + self.assertEqual({}, datasource.metadata) + mock_fqdn = 'cloudinit.sources.util.get_fqdn_from_hosts' + with mock.patch('cloudinit.sources.util.get_hostname') as m_gethost: + with mock.patch(mock_fqdn) as m_fqdn: + m_gethost.return_value = 'systemhostname.domain.com' + m_fqdn.return_value = None # No maching fqdn in /etc/hosts + self.assertEqual('systemhostname', datasource.get_hostname()) + self.assertEqual( + 'systemhostname.domain.com', + datasource.get_hostname(fqdn=True)) + + def test_get_hostname_without_metadata_returns_none(self): + """Datasource.gethostname returns None when metadata_only and no MD.""" + tmp = self.tmp_dir() + datasource = DataSourceTestSubclassNet( + self.sys_cfg, self.distro, Paths({'run_dir': tmp})) + self.assertEqual({}, datasource.metadata) + mock_fqdn = 'cloudinit.sources.util.get_fqdn_from_hosts' + with mock.patch('cloudinit.sources.util.get_hostname') as m_gethost: + with mock.patch(mock_fqdn) as m_fqdn: + self.assertIsNone(datasource.get_hostname(metadata_only=True)) + self.assertIsNone( + datasource.get_hostname(fqdn=True, metadata_only=True)) + self.assertEqual([], m_gethost.call_args_list) + self.assertEqual([], m_fqdn.call_args_list) + + def test_get_hostname_without_metadata_prefers_etc_hosts(self): + """Datasource.gethostname prefers /etc/hosts to util.get_hostname.""" + tmp = self.tmp_dir() + datasource = DataSourceTestSubclassNet( + self.sys_cfg, self.distro, Paths({'run_dir': tmp})) + self.assertEqual({}, datasource.metadata) + mock_fqdn = 'cloudinit.sources.util.get_fqdn_from_hosts' + with mock.patch('cloudinit.sources.util.get_hostname') as m_gethost: + with mock.patch(mock_fqdn) as m_fqdn: + m_gethost.return_value = 'systemhostname.domain.com' + m_fqdn.return_value = 'fqdnhostname.domain.com' + self.assertEqual('fqdnhostname', datasource.get_hostname()) + self.assertEqual('fqdnhostname.domain.com', + datasource.get_hostname(fqdn=True)) + def test_get_data_write_json_instance_data(self): """get_data writes INSTANCE_JSON_FILE to run_dir as readonly root.""" tmp = self.tmp_dir() -- cgit v1.2.3