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/cmd/main.py | 25 ++++++ cloudinit/cmd/tests/test_main.py | 161 +++++++++++++++++++++++++++++++++++++++ 2 files changed, 186 insertions(+) create mode 100644 cloudinit/cmd/tests/test_main.py (limited to 'cloudinit/cmd') diff --git a/cloudinit/cmd/main.py b/cloudinit/cmd/main.py index fcddd75c..3f2dbb93 100644 --- a/cloudinit/cmd/main.py +++ b/cloudinit/cmd/main.py @@ -40,6 +40,7 @@ from cloudinit.settings import (PER_INSTANCE, PER_ALWAYS, PER_ONCE, from cloudinit import atomic_helper +from cloudinit.config import cc_set_hostname from cloudinit.dhclient_hook import LogDhclient @@ -352,6 +353,11 @@ def main_init(name, args): LOG.debug("[%s] %s will now be targeting instance id: %s. new=%s", mode, name, iid, init.is_new_instance()) + if mode == sources.DSMODE_LOCAL: + # Before network comes up, set any configured hostname to allow + # dhcp clients to advertize this hostname to any DDNS services + # LP: #1746455. + _maybe_set_hostname(init, stage='local', retry_stage='network') init.apply_network_config(bring_up=bool(mode != sources.DSMODE_LOCAL)) if mode == sources.DSMODE_LOCAL: @@ -368,6 +374,7 @@ def main_init(name, args): init.setup_datasource() # update fully realizes user-data (pulling in #include if necessary) init.update() + _maybe_set_hostname(init, stage='init-net', retry_stage='modules:config') # Stage 7 try: # Attempt to consume the data per instance. @@ -681,6 +688,24 @@ def status_wrapper(name, args, data_d=None, link_d=None): return len(v1[mode]['errors']) +def _maybe_set_hostname(init, stage, retry_stage): + """Call set-hostname if metadata, vendordata or userdata provides it. + + @param stage: String representing current stage in which we are running. + @param retry_stage: String represented logs upon error setting hostname. + """ + cloud = init.cloudify() + (hostname, _fqdn) = util.get_hostname_fqdn( + init.cfg, cloud, metadata_only=True) + if hostname: # meta-data or user-data hostname content + try: + cc_set_hostname.handle('set-hostname', init.cfg, cloud, LOG, None) + except cc_set_hostname.SetHostnameError as e: + LOG.debug( + 'Failed setting hostname in %s stage. Will' + ' retry in %s stage. Error: %s.', stage, retry_stage, str(e)) + + def main_features(name, args): sys.stdout.write('\n'.join(sorted(version.FEATURES)) + '\n') diff --git a/cloudinit/cmd/tests/test_main.py b/cloudinit/cmd/tests/test_main.py new file mode 100644 index 00000000..dbe421c0 --- /dev/null +++ b/cloudinit/cmd/tests/test_main.py @@ -0,0 +1,161 @@ +# This file is part of cloud-init. See LICENSE file for license information. + +from collections import namedtuple +import copy +import os +from six import StringIO + +from cloudinit.cmd import main +from cloudinit.util import ( + ensure_dir, load_file, write_file, yaml_dumps) +from cloudinit.tests.helpers import ( + FilesystemMockingTestCase, wrap_and_call) + +mypaths = namedtuple('MyPaths', 'run_dir') +myargs = namedtuple('MyArgs', 'debug files force local reporter subcommand') + + +class TestMain(FilesystemMockingTestCase): + + with_logs = True + + def setUp(self): + super(TestMain, self).setUp() + self.new_root = self.tmp_dir() + self.cloud_dir = self.tmp_path('var/lib/cloud/', dir=self.new_root) + os.makedirs(self.cloud_dir) + self.replicateTestRoot('simple_ubuntu', self.new_root) + self.cfg = { + 'datasource_list': ['None'], + 'runcmd': ['ls /etc'], # test ALL_DISTROS + 'system_info': {'paths': {'cloud_dir': self.cloud_dir, + 'run_dir': self.new_root}}, + 'write_files': [ + { + 'path': '/etc/blah.ini', + 'content': 'blah', + 'permissions': 0o755, + }, + ], + 'cloud_init_modules': ['write-files', 'runcmd'], + } + cloud_cfg = yaml_dumps(self.cfg) + ensure_dir(os.path.join(self.new_root, 'etc', 'cloud')) + self.cloud_cfg_file = os.path.join( + self.new_root, 'etc', 'cloud', 'cloud.cfg') + write_file(self.cloud_cfg_file, cloud_cfg) + self.patchOS(self.new_root) + self.patchUtils(self.new_root) + self.stderr = StringIO() + self.patchStdoutAndStderr(stderr=self.stderr) + + def test_main_init_run_net_stops_on_file_no_net(self): + """When no-net file is present, main_init does not process modules.""" + stop_file = os.path.join(self.cloud_dir, 'data', 'no-net') # stop file + write_file(stop_file, '') + cmdargs = myargs( + debug=False, files=None, force=False, local=False, reporter=None, + subcommand='init') + (item1, item2) = wrap_and_call( + 'cloudinit.cmd.main', + {'util.close_stdin': True, + 'netinfo.debug_info': 'my net debug info', + 'util.fixup_output': ('outfmt', 'errfmt')}, + main.main_init, 'init', cmdargs) + # We should not run write_files module + self.assertFalse( + os.path.exists(os.path.join(self.new_root, 'etc/blah.ini')), + 'Unexpected run of write_files module produced blah.ini') + self.assertEqual([], item2) + # Instancify is called + instance_id_path = 'var/lib/cloud/data/instance-id' + self.assertFalse( + os.path.exists(os.path.join(self.new_root, instance_id_path)), + 'Unexpected call to datasource.instancify produced instance-id') + expected_logs = [ + "Exiting. stop file ['{stop_file}'] existed\n".format( + stop_file=stop_file), + 'my net debug info' # netinfo.debug_info + ] + for log in expected_logs: + self.assertIn(log, self.stderr.getvalue()) + + def test_main_init_run_net_runs_modules(self): + """Modules like write_files are run in 'net' mode.""" + cmdargs = myargs( + debug=False, files=None, force=False, local=False, reporter=None, + subcommand='init') + (item1, item2) = wrap_and_call( + 'cloudinit.cmd.main', + {'util.close_stdin': True, + 'netinfo.debug_info': 'my net debug info', + 'util.fixup_output': ('outfmt', 'errfmt')}, + main.main_init, 'init', cmdargs) + self.assertEqual([], item2) + # Instancify is called + instance_id_path = 'var/lib/cloud/data/instance-id' + self.assertEqual( + 'iid-datasource-none\n', + os.path.join(load_file( + os.path.join(self.new_root, instance_id_path)))) + # modules are run (including write_files) + self.assertEqual( + 'blah', load_file(os.path.join(self.new_root, 'etc/blah.ini'))) + expected_logs = [ + 'network config is disabled by fallback', # apply_network_config + 'my net debug info', # netinfo.debug_info + 'no previous run detected' + ] + for log in expected_logs: + self.assertIn(log, self.stderr.getvalue()) + + def test_main_init_run_net_calls_set_hostname_when_metadata_present(self): + """When local-hostname metadata is present, call cc_set_hostname.""" + self.cfg['datasource'] = { + 'None': {'metadata': {'local-hostname': 'md-hostname'}}} + cloud_cfg = yaml_dumps(self.cfg) + write_file(self.cloud_cfg_file, cloud_cfg) + cmdargs = myargs( + debug=False, files=None, force=False, local=False, reporter=None, + subcommand='init') + + def set_hostname(name, cfg, cloud, log, args): + self.assertEqual('set-hostname', name) + updated_cfg = copy.deepcopy(self.cfg) + updated_cfg.update( + {'def_log_file': '/var/log/cloud-init.log', + 'log_cfgs': [], + 'syslog_fix_perms': ['syslog:adm', 'root:adm', 'root:wheel'], + 'vendor_data': {'enabled': True, 'prefix': []}}) + updated_cfg.pop('system_info') + + self.assertEqual(updated_cfg, cfg) + self.assertEqual(main.LOG, log) + self.assertIsNone(args) + + (item1, item2) = wrap_and_call( + 'cloudinit.cmd.main', + {'util.close_stdin': True, + 'netinfo.debug_info': 'my net debug info', + 'cc_set_hostname.handle': {'side_effect': set_hostname}, + 'util.fixup_output': ('outfmt', 'errfmt')}, + main.main_init, 'init', cmdargs) + self.assertEqual([], item2) + # Instancify is called + instance_id_path = 'var/lib/cloud/data/instance-id' + self.assertEqual( + 'iid-datasource-none\n', + os.path.join(load_file( + os.path.join(self.new_root, instance_id_path)))) + # modules are run (including write_files) + self.assertEqual( + 'blah', load_file(os.path.join(self.new_root, 'etc/blah.ini'))) + expected_logs = [ + 'network config is disabled by fallback', # apply_network_config + 'my net debug info', # netinfo.debug_info + 'no previous run detected' + ] + for log in expected_logs: + self.assertIn(log, self.stderr.getvalue()) + +# vi: ts=4 expandtab -- cgit v1.2.3