From 80476c7dea2b3f6f42ebce5a7947af1d3b9dbedb Mon Sep 17 00:00:00 2001 From: Rodolfo Carvalho Date: Fri, 23 Jun 2017 15:32:19 +0200 Subject: Rewrite failure summary callback plugin The intent is to deduplicate similar errors that happened in many hosts, making the summary more concise. --- .../callback_plugins/zz_failure_summary.py | 291 ++++++++++++--------- roles/openshift_health_checker/test/conftest.py | 1 + .../test/zz_failure_summary_test.py | 70 +++++ 3 files changed, 243 insertions(+), 119 deletions(-) create mode 100644 roles/openshift_health_checker/test/zz_failure_summary_test.py diff --git a/roles/openshift_health_checker/callback_plugins/zz_failure_summary.py b/roles/openshift_health_checker/callback_plugins/zz_failure_summary.py index 9f9fe123a..46cc3b577 100644 --- a/roles/openshift_health_checker/callback_plugins/zz_failure_summary.py +++ b/roles/openshift_health_checker/callback_plugins/zz_failure_summary.py @@ -1,161 +1,214 @@ -""" -Ansible callback plugin to give a nicely formatted summary of failures. -""" +"""Ansible callback plugin to print a nicely formatted summary of failures. -# Reason: In several locations below we disable pylint protected-access -# for Ansible objects that do not give us any public way -# to access the full details we need to report check failures. -# Status: disabled permanently or until Ansible object has a public API. -# This does leave the code more likely to be broken by future Ansible changes. +The file / module name is prefixed with `zz_` to make this plugin be loaded last +by Ansible, thus making its output the last thing that users see. +""" -from pprint import pformat +from collections import defaultdict from ansible.plugins.callback import CallbackBase from ansible import constants as C from ansible.utils.color import stringc +FAILED_NO_MSG = u'Failed without returning a message.' + + class CallbackModule(CallbackBase): - """ - This callback plugin stores task results and summarizes failures. - The file name is prefixed with `zz_` to make this plugin be loaded last by - Ansible, thus making its output the last thing that users see. - """ + """This callback plugin stores task results and summarizes failures.""" CALLBACK_VERSION = 2.0 CALLBACK_TYPE = 'aggregate' CALLBACK_NAME = 'failure_summary' CALLBACK_NEEDS_WHITELIST = False - _playbook_file = None def __init__(self): super(CallbackModule, self).__init__() self.__failures = [] + self.__playbook_file = '' def v2_playbook_on_start(self, playbook): super(CallbackModule, self).v2_playbook_on_start(playbook) - # re: playbook attrs see top comment # pylint: disable=protected-access - self._playbook_file = playbook._file_name + # pylint: disable=protected-access; Ansible gives us no public API to + # get the file name of the current playbook from a callback plugin. + self.__playbook_file = playbook._file_name def v2_runner_on_failed(self, result, ignore_errors=False): super(CallbackModule, self).v2_runner_on_failed(result, ignore_errors) if not ignore_errors: - self.__failures.append(dict(result=result, ignore_errors=ignore_errors)) + self.__failures.append(result) def v2_playbook_on_stats(self, stats): super(CallbackModule, self).v2_playbook_on_stats(stats) if self.__failures: - self._print_failure_details(self.__failures) - - def _print_failure_details(self, failures): - """Print a summary of failed tasks or checks.""" - self._display.display(u'\nFailure summary:\n') - - width = len(str(len(failures))) - initial_indent_format = u' {{:>{width}}}. '.format(width=width) - initial_indent_len = len(initial_indent_format.format(0)) - subsequent_indent = u' ' * initial_indent_len - subsequent_extra_indent = u' ' * (initial_indent_len + 10) - - for i, failure in enumerate(failures, 1): - entries = _format_failure(failure) - self._display.display(u'\n{}{}'.format(initial_indent_format.format(i), entries[0])) - for entry in entries[1:]: - entry = entry.replace(u'\n', u'\n' + subsequent_extra_indent) - indented = u'{}{}'.format(subsequent_indent, entry) - self._display.display(indented) - - failed_checks = set() - playbook_context = None - # re: result attrs see top comment # pylint: disable=protected-access - for failure in failures: - # Get context from check task result since callback plugins cannot access task vars. - # NOTE: thus context is not known unless checks run. Failures prior to checks running - # don't have playbook_context in the results. But we only use it now when checks fail. - playbook_context = playbook_context or failure['result']._result.get('playbook_context') - failed_checks.update( - name - for name, result in failure['result']._result.get('checks', {}).items() - if result.get('failed') - ) - if failed_checks: - self._print_check_failure_summary(failed_checks, playbook_context) - - def _print_check_failure_summary(self, failed_checks, context): - checks = ','.join(sorted(failed_checks)) - # The purpose of specifying context is to vary the output depending on what the user was - # expecting to happen (based on which playbook they ran). The only use currently is to - # vary the message depending on whether the user was deliberately running checks or was - # trying to install/upgrade and checks are just included. Other use cases may arise. - summary = ( # default to explaining what checks are in the first place - '\n' - 'The execution of "{playbook}"\n' - 'includes checks designed to fail early if the requirements\n' - 'of the playbook are not met. One or more of these checks\n' - 'failed. To disregard these results, you may choose to\n' - 'disable failing checks by setting an Ansible variable:\n\n' - ' openshift_disable_check={checks}\n\n' - 'Failing check names are shown in the failure details above.\n' - 'Some checks may be configurable by variables if your requirements\n' - 'are different from the defaults; consult check documentation.\n' - 'Variables can be set in the inventory or passed on the\n' - 'command line using the -e flag to ansible-playbook.\n\n' - ).format(playbook=self._playbook_file, checks=checks) - if context in ['pre-install', 'health', 'adhoc']: - summary = ( # user was expecting to run checks, less explanation needed - '\n' - 'You may choose to configure or disable failing checks by\n' - 'setting Ansible variables. To disable those above:\n\n' - ' openshift_disable_check={checks}\n\n' - 'Consult check documentation for configurable variables.\n' - 'Variables can be set in the inventory or passed on the\n' - 'command line using the -e flag to ansible-playbook.\n\n' - ).format(checks=checks) - self._display.display(summary) - - -# re: result attrs see top comment # pylint: disable=protected-access -def _format_failure(failure): + self._display.display(failure_summary(self.__failures, self.__playbook_file)) + + +def failure_summary(failures, playbook): + """Return a summary of failed tasks, including details on health checks.""" + if not failures: + return u'' + + # NOTE: because we don't have access to task_vars from callback plugins, we + # store the playbook context in the task result when the + # openshift_health_check action plugin is used, and we use this context to + # customize the error message. + # pylint: disable=protected-access; Ansible gives us no sufficient public + # API on TaskResult objects. + context = next(( + context for context in + (failure._result.get('playbook_context') for failure in failures) + if context + ), None) + + failures = [failure_to_dict(failure) for failure in failures] + failures = deduplicate_failures(failures) + + summary = [u'', u'', u'Failure summary:', u''] + + width = len(str(len(failures))) + initial_indent_format = u' {{:>{width}}}. '.format(width=width) + initial_indent_len = len(initial_indent_format.format(0)) + subsequent_indent = u' ' * initial_indent_len + subsequent_extra_indent = u' ' * (initial_indent_len + 10) + + for i, failure in enumerate(failures, 1): + entries = format_failure(failure) + summary.append(u'\n{}{}'.format(initial_indent_format.format(i), entries[0])) + for entry in entries[1:]: + entry = entry.replace(u'\n', u'\n' + subsequent_extra_indent) + indented = u'{}{}'.format(subsequent_indent, entry) + summary.append(indented) + + failed_checks = set() + for failure in failures: + failed_checks.update(name for name, message in failure['checks']) + if failed_checks: + summary.append(check_failure_footer(failed_checks, context, playbook)) + + return u'\n'.join(summary) + + +def failure_to_dict(failed_task_result): + """Extract information out of a failed TaskResult into a dict. + + The intent is to transform a TaskResult object into something easier to + manipulate. TaskResult is ansible.executor.task_result.TaskResult. + """ + # pylint: disable=protected-access; Ansible gives us no sufficient public + # API on TaskResult objects. + _result = failed_task_result._result + return { + 'host': failed_task_result._host.get_name(), + 'play': play_name(failed_task_result._task), + 'task': failed_task_result.task_name, + 'msg': _result.get('msg', FAILED_NO_MSG), + 'checks': tuple( + (name, result.get('msg', FAILED_NO_MSG)) + for name, result in sorted(_result.get('checks', {}).items()) + if result.get('failed') + ), + } + + +def play_name(obj): + """Given a task or block, return the name of its parent play. + + This is loosely inspired by ansible.playbook.base.Base.dump_me. + """ + # pylint: disable=protected-access; Ansible gives us no sufficient public + # API to implement this. + if not obj: + return '' + if hasattr(obj, '_play'): + return obj._play.get_name() + return play_name(getattr(obj, '_parent')) + + +def deduplicate_failures(failures): + """Group together similar failures from different hosts. + + Returns a new list of failures such that identical failures from different + hosts are grouped together in a single entry. The relative order of failures + is preserved. + """ + groups = defaultdict(list) + for failure in failures: + group_key = tuple(sorted((key, value) for key, value in failure.items() if key != 'host')) + groups[group_key].append(failure) + result = [] + for failure in failures: + group_key = tuple(sorted((key, value) for key, value in failure.items() if key != 'host')) + if group_key not in groups: + continue + failure['host'] = tuple(sorted(g_failure['host'] for g_failure in groups.pop(group_key))) + result.append(failure) + return result + + +def format_failure(failure): """Return a list of pretty-formatted text entries describing a failure, including relevant information about it. Expect that the list of text entries will be joined by a newline separator when output to the user.""" - result = failure['result'] - host = result._host.get_name() - play = _get_play(result._task) - if play: - play = play.get_name() - task = result._task.get_name() - msg = result._result.get('msg', u'???') + host = u', '.join(failure['host']) + play = failure['play'] + task = failure['task'] + msg = failure['msg'] + checks = failure['checks'] fields = ( - (u'Host', host), + (u'Hosts', host), (u'Play', play), (u'Task', task), (u'Message', stringc(msg, C.COLOR_ERROR)), ) - if 'checks' in result._result: - fields += ((u'Details', _format_failed_checks(result._result['checks'])),) + if checks: + fields += ((u'Details', format_failed_checks(checks)),) row_format = '{:10}{}' return [row_format.format(header + u':', body) for header, body in fields] -def _format_failed_checks(checks): +def format_failed_checks(checks): """Return pretty-formatted text describing checks that failed.""" - failed_check_msgs = [] - for check, body in checks.items(): - if body.get('failed', False): # only show the failed checks - msg = body.get('msg', u"Failed without returning a message") - failed_check_msgs.append('check "%s":\n%s' % (check, msg)) - if failed_check_msgs: - return stringc("\n\n".join(failed_check_msgs), C.COLOR_ERROR) - else: # something failed but no checks will admit to it, so dump everything - return stringc(pformat(checks), C.COLOR_ERROR) - - -# This is inspired by ansible.playbook.base.Base.dump_me. -# re: play/task/block attrs see top comment # pylint: disable=protected-access -def _get_play(obj): - """Given a task or block, recursively try to find its parent play.""" - if hasattr(obj, '_play'): - return obj._play - if getattr(obj, '_parent'): - return _get_play(obj._parent) + messages = [] + for name, message in checks: + messages.append(u'check "{}":\n{}'.format(name, message)) + return stringc(u'\n\n'.join(messages), C.COLOR_ERROR) + + +def check_failure_footer(failed_checks, context, playbook): + """Return a textual explanation about checks depending on context. + + The purpose of specifying context is to vary the output depending on what + the user was expecting to happen (based on which playbook they ran). The + only use currently is to vary the message depending on whether the user was + deliberately running checks or was trying to install/upgrade and checks are + just included. Other use cases may arise. + """ + checks = ','.join(sorted(failed_checks)) + summary = [u''] + if context in ['pre-install', 'health', 'adhoc']: + # User was expecting to run checks, less explanation needed. + summary.extend([ + u'You may configure or disable checks by setting Ansible ' + u'variables. To disable those above, set:', + u' openshift_disable_check={checks}'.format(checks=checks), + u'Consult check documentation for configurable variables.', + ]) + else: + # User may not be familiar with the checks, explain what checks are in + # the first place. + summary.extend([ + u'The execution of "{playbook}" includes checks designed to fail ' + u'early if the requirements of the playbook are not met. One or ' + u'more of these checks failed. To disregard these results,' + u'explicitly disable checks by setting an Ansible variable:'.format(playbook=playbook), + u' openshift_disable_check={checks}'.format(checks=checks), + u'Failing check names are shown in the failure details above. ' + u'Some checks may be configurable by variables if your requirements ' + u'are different from the defaults; consult check documentation.', + ]) + summary.append( + u'Variables can be set in the inventory or passed on the command line ' + u'using the -e flag to ansible-playbook.' + ) + return u'\n'.join(summary) diff --git a/roles/openshift_health_checker/test/conftest.py b/roles/openshift_health_checker/test/conftest.py index 3cbd65507..244a1f0fa 100644 --- a/roles/openshift_health_checker/test/conftest.py +++ b/roles/openshift_health_checker/test/conftest.py @@ -7,5 +7,6 @@ openshift_health_checker_path = os.path.dirname(os.path.dirname(__file__)) sys.path[1:1] = [ openshift_health_checker_path, os.path.join(openshift_health_checker_path, 'action_plugins'), + os.path.join(openshift_health_checker_path, 'callback_plugins'), os.path.join(openshift_health_checker_path, 'library'), ] diff --git a/roles/openshift_health_checker/test/zz_failure_summary_test.py b/roles/openshift_health_checker/test/zz_failure_summary_test.py new file mode 100644 index 000000000..0fc258133 --- /dev/null +++ b/roles/openshift_health_checker/test/zz_failure_summary_test.py @@ -0,0 +1,70 @@ +from zz_failure_summary import deduplicate_failures + +import pytest + + +@pytest.mark.parametrize('failures,deduplicated', [ + ( + [ + { + 'host': 'master1', + 'msg': 'One or more checks failed', + }, + ], + [ + { + 'host': ('master1',), + 'msg': 'One or more checks failed', + }, + ], + ), + ( + [ + { + 'host': 'master1', + 'msg': 'One or more checks failed', + }, + { + 'host': 'node1', + 'msg': 'One or more checks failed', + }, + ], + [ + { + 'host': ('master1', 'node1'), + 'msg': 'One or more checks failed', + }, + ], + ), + ( + [ + { + 'host': 'node1', + 'msg': 'One or more checks failed', + 'checks': (('test_check', 'error message'),), + }, + { + 'host': 'master2', + 'msg': 'Some error happened', + }, + { + 'host': 'master1', + 'msg': 'One or more checks failed', + 'checks': (('test_check', 'error message'),), + }, + ], + [ + { + 'host': ('master1', 'node1'), + 'msg': 'One or more checks failed', + 'checks': (('test_check', 'error message'),), + }, + { + 'host': ('master2',), + 'msg': 'Some error happened', + }, + ], + ), +]) +def test_deduplicate_failures(failures, deduplicated): + assert deduplicate_failures(failures) == deduplicated -- cgit v1.2.3