Bug fix for fetching a goal state with empty certificates property (A…

…zure#2575)

azurelinuxagent/common/protocol/goal_state.py

@@ -82,7 +82,7 @@ def __init__(self, wire_client, silent=False):
  self._container_id = None
  self._hosting_env = None
  self._shared_conf = None
- self._certs = None
+ self._certs = EmptyCertificates()
  self._remote_access = None
 
  self.update(silent=silent)
@@ -348,7 +348,7 @@ def _fetch_full_wire_server_goal_state(self, incarnation, xml_doc):
  shared_conf = SharedConfig(xml_text)
  self._history.save_shared_conf(xml_text)
 
- certs = None
+ certs = EmptyCertificates()
  certs_uri = findtext(xml_doc, "Certificates")
  if certs_uri is not None:
  xml_text = self._wire_client.fetch_config(certs_uri, self._wire_client.get_header_for_cert())
@@ -506,6 +506,11 @@ def _write_to_tmp_file(index, suffix, buf):
  fileutil.write_file(file_name, "".join(buf))
  return file_name
 
+class EmptyCertificates:
+ def __init__(self):
+ self.cert_list = CertList()
+ self.summary = [] # debugging info
+ self.warnings = []
 
 class RemoteAccess(object):
  """

tests/data/wire/goal_state_no_certs.xml

@@ -0,0 +1,27 @@
+<?xml version="1.0" encoding="utf-8"?>
+<GoalState xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="goalstate10.xsd">
+ <Version>2010-12-15</Version>
+ <Incarnation>1</Incarnation>
+ <Machine>
+ <ExpectedState>Started</ExpectedState>
+ <LBProbePorts>
+ <Port>16001</Port>
+ </LBProbePorts>
+ </Machine>
+ <Container>
+ <ContainerId>c6d5526c-5ac2-4200-b6e2-56f2b70c5ab2</ContainerId>
+ <RoleInstanceList>
+ <RoleInstance>
+ <InstanceId>b61f93d0-e1ed-40b2-b067-22c243233448.MachineRole_IN_0</InstanceId>
+ <State>Started</State>
+ <Configuration>
+ <HostingEnvironmentConfig>http://168.63.129.16:80/machine/865a6683-91d8-450f-99ae/bc8b9d47%2Db5ed%2D4704%2D85d9%2Dfd74cc967ec2.%5Fcanary?comp=config&amp;type=hostingEnvironmentConfig&amp;incarnation=1</HostingEnvironmentConfig>
+ <SharedConfig>http://168.63.129.16:80/machine/865a6683-91d8-450f-99ae/bc8b9d47%2Db5ed%2D4704%2D85d9%2Dfd74cc967ec2.%5Fcanary?comp=config&amp;type=sharedConfig&amp;incarnation=1</SharedConfig>
+ <ExtensionsConfig>http://168.63.129.16:80/machine/865a6683-91d8-450f-99ae/bc8b9d47%2Db5ed%2D4704%2D85d9%2Dfd74cc967ec2.%5Fcanary?comp=config&amp;type=extensionsConfig&amp;incarnation=1</ExtensionsConfig>
+ <FullConfig>http://168.63.129.16:80/machine/865a6683-91d8-450f-99ae/bc8b9d47%2Db5ed%2D4704%2D85d9%2Dfd74cc967ec2.%5Fcanary?comp=config&amp;type=fullConfig&amp;incarnation=1</FullConfig>
+ <ConfigName>bc8b9d47-b5ed-4704-85d9-fd74cc967ec2.5.bc8b9d47-b5ed-4704-85d9-fd74cc967ec2.5._canary.1.xml</ConfigName>
+ </Configuration>
+ </RoleInstance>
+ </RoleInstanceList>
+ </Container>
+ </GoalState>

tests/ga/test_update.py

@@ -1564,6 +1564,53 @@ def _get_test_ext_handler_instance(protocol, name="OSTCExtensions.ExampleHandler
  eh = Extension(name=name)
  eh.version = version
  return ExtHandlerInstance(eh, protocol)
+
+ def test_update_handler_recovers_from_error_with_no_certs(self):
+ data = DATA_FILE.copy()
+ data['goal_state'] = 'wire/goal_state_no_certs.xml'
+
+ def fail_gs_fetch(url, *_, **__):
+ if HttpRequestPredicates.is_goal_state_request(url):
+ return MockHttpResponse(status=500)
+ return None
+
+ with mock_wire_protocol(data) as protocol:
+
+ def fail_fetch_on_second_iter(iteration):
+ if iteration == 2:
+ protocol.set_http_handlers(http_get_handler=fail_gs_fetch)
+ if iteration > 2: # Zero out the fail handler for subsequent iterations.
+ protocol.set_http_handlers(http_get_handler=None)
+
+ with mock_update_handler(protocol, 3, on_new_iteration=fail_fetch_on_second_iter) as update_handler:
+ with patch("azurelinuxagent.ga.update.logger.error") as patched_error:
+ with patch("azurelinuxagent.ga.update.logger.info") as patched_info:
+ def match_unexpected_errors():
+ unexpected_msg_fragment = "Error fetching the goal state:"
+
+ matching_errors = []
+ for (args, _) in filter(lambda a: len(a) > 0, patched_error.call_args_list):
+ if unexpected_msg_fragment in args[0]:
+ matching_errors.append(args[0])
+
+ if len(matching_errors) > 1:
+ self.fail("Guest Agent did not recover, with new error(s): {}"\
+ .format(matching_errors[1:]))
+
+ def match_expected_info():
+ expected_msg_fragment = "Fetching the goal state recovered from previous errors"
+
+ for (call_args, _) in filter(lambda a: len(a) > 0, patched_info.call_args_list):
+ if expected_msg_fragment in call_args[0]:
+ break
+ else:
+ self.fail("Expected the guest agent to recover with '{}', but it didn't"\
+ .format(expected_msg_fragment))
+
+ update_handler.run(debug=True)
+ match_unexpected_errors() # Match on errors first, they can provide more info.
+ match_expected_info()
+
 
  def test_it_should_recreate_handler_env_on_service_startup(self):
  iterations = 5