salt/tests/support/helpers.py

# -*- coding: utf-8 -*-
'''
    :copyright: Copyright 2013-2017 by the SaltStack Team, see AUTHORS for more details.
    :license: Apache 2.0, see LICENSE for more details.


    tests.support.helpers
    ~~~~~~~~~~~~~~~~~~~~~

    Test support helpers
'''
# pylint: disable=repr-flag-used-in-string,wrong-import-order

# Import Python libs
from __future__ import absolute_import, print_function, unicode_literals
import base64
import errno
import functools
import inspect
import logging
import os
import random
import shutil
import signal
import socket
import string
import subprocess
import sys
import tempfile
import textwrap
import threading
import time
import tornado.ioloop
import tornado.web
import types

# Import 3rd-party libs
import psutil  # pylint: disable=3rd-party-module-not-gated
from salt.ext import six
from salt.ext.six.moves import range, builtins  # pylint: disable=import-error,redefined-builtin
try:
    from pytestsalt.utils import get_unused_localhost_port  # pylint: disable=unused-import
except ImportError:
    from tests.integration import get_unused_localhost_port

# Import Salt Tests Support libs
from tests.support.unit import skip, _id
from tests.support.mock import patch
from tests.support.paths import FILES, TMP

# Import Salt libs
import salt.utils.files
import salt.utils.platform
import salt.utils.stringutils

if salt.utils.platform.is_windows():
    import salt.utils.win_functions
else:
    import pwd

log = logging.getLogger(__name__)

HAS_SYMLINKS = None


def no_symlinks():
    '''
    Check if git is installed and has symlinks enabled in the configuration.
    '''
    global HAS_SYMLINKS
    if HAS_SYMLINKS is not None:
        return not HAS_SYMLINKS
    output = ''
    try:
        output = subprocess.Popen(
            ['git', 'config', '--get', 'core.symlinks'],
            cwd=TMP,
            stdout=subprocess.PIPE).communicate()[0]
    except OSError as exc:
        if exc.errno != errno.ENOENT:
            raise
    except subprocess.CalledProcessError:
        # git returned non-zero status
        pass
    HAS_SYMLINKS = False
    if output.strip() == 'true':
        HAS_SYMLINKS = True
    return not HAS_SYMLINKS


def destructiveTest(caller):
    '''
    Mark a test case as a destructive test for example adding or removing users
    from your system.

    .. code-block:: python

        class MyTestCase(TestCase):

            @destructiveTest
            def test_create_user(self):
                pass
    '''
    if inspect.isclass(caller):
        # We're decorating a class
        old_setup = getattr(caller, 'setUp', None)

        def setUp(self, *args, **kwargs):
            if os.environ.get('DESTRUCTIVE_TESTS', 'False').lower() == 'false':
                self.skipTest('Destructive tests are disabled')
            if old_setup is not None:
                old_setup(self, *args, **kwargs)
        caller.setUp = setUp
        return caller

    # We're simply decorating functions
    @functools.wraps(caller)
    def wrap(cls):
        if os.environ.get('DESTRUCTIVE_TESTS', 'False').lower() == 'false':
            cls.skipTest('Destructive tests are disabled')
        return caller(cls)
    return wrap


def expensiveTest(caller):
    '''
    Mark a test case as an expensive test, for example, a test which can cost
    money(Salt's cloud provider tests).

    .. code-block:: python

        class MyTestCase(TestCase):

            @expensiveTest
            def test_create_user(self):
                pass
    '''
    if inspect.isclass(caller):
        # We're decorating a class
        old_setup = getattr(caller, 'setUp', None)

        def setUp(self, *args, **kwargs):
            if os.environ.get('EXPENSIVE_TESTS', 'False').lower() == 'false':
                self.skipTest('Expensive tests are disabled')
            if old_setup is not None:
                old_setup(self, *args, **kwargs)
        caller.setUp = setUp
        return caller

    # We're simply decorating functions
    @functools.wraps(caller)
    def wrap(cls):
        if os.environ.get('EXPENSIVE_TESTS', 'False').lower() == 'false':
            cls.skipTest('Expensive tests are disabled')
        return caller(cls)
    return wrap


def flaky(caller=None, condition=True, attempts=4):
    '''
    Mark a test as flaky. The test will attempt to run five times,
    looking for a successful run. After an immediate second try,
    it will use an exponential backoff starting with one second.

    .. code-block:: python

        class MyTestCase(TestCase):

        @flaky
        def test_sometimes_works(self):
            pass
    '''
    if caller is None:
        return functools.partial(flaky, condition=condition, attempts=attempts)

    if isinstance(condition, bool) and condition is False:
        # Don't even decorate
        return caller
    elif callable(condition):
        if condition() is False:
            # Don't even decorate
            return caller

    if inspect.isclass(caller):
        attrs = [n for n in dir(caller) if n.startswith('test_')]
        for attrname in attrs:
            try:
                function = getattr(caller, attrname)
                if not inspect.isfunction(function) and not inspect.ismethod(function):
                    continue
                setattr(caller, attrname, flaky(caller=function, condition=condition, attempts=attempts))
            except Exception as exc:
                log.exception(exc)
                continue
        return caller

    @functools.wraps(caller)
    def wrap(cls):
        for attempt in range(0, attempts):
            try:
                return caller(cls)
            except Exception as exc:
                if attempt >= attempts -1:
                    raise exc
                backoff_time = attempt ** 2
                log.info(
                    'Found Exception. Waiting %s seconds to retry.',
                    backoff_time
                )
                time.sleep(backoff_time)
        return cls
    return wrap


def requires_sshd_server(caller):
    '''
    Mark a test as requiring the tests SSH daemon running.

    .. code-block:: python

        class MyTestCase(TestCase):

            @requiresSshdServer
            def test_create_user(self):
                pass
    '''
    if inspect.isclass(caller):
        # We're decorating a class
        old_setup = getattr(caller, 'setUp', None)

        def setUp(self, *args, **kwargs):
            if os.environ.get('SSH_DAEMON_RUNNING', 'False').lower() == 'false':
                self.skipTest('SSH tests are disabled')
            if old_setup is not None:
                old_setup(self, *args, **kwargs)
        caller.setUp = setUp
        return caller

    # We're simply decorating functions
    @functools.wraps(caller)
    def wrap(cls):
        if os.environ.get('SSH_DAEMON_RUNNING', 'False').lower() == 'false':
            cls.skipTest('SSH tests are disabled')
        return caller(cls)
    return wrap


class RedirectStdStreams(object):
    '''
    Temporarily redirect system output to file like objects.
    Default is to redirect to `os.devnull`, which just mutes output, `stdout`
    and `stderr`.
    '''

    def __init__(self, stdout=None, stderr=None):
        # Late import
        import salt.utils.files
        if stdout is None:
            stdout = salt.utils.files.fopen(os.devnull, 'w')  # pylint: disable=resource-leakage
        if stderr is None:
            stderr = salt.utils.files.fopen(os.devnull, 'w')  # pylint: disable=resource-leakage

        self.__stdout = stdout
        self.__stderr = stderr
        self.__redirected = False
        self.patcher = patch.multiple(sys, stderr=self.__stderr, stdout=self.__stdout)

    def __enter__(self):
        self.redirect()
        return self

    def __exit__(self, exc_type, exc_value, traceback):
        self.unredirect()

    def redirect(self):
        self.old_stdout = sys.stdout
        self.old_stdout.flush()
        self.old_stderr = sys.stderr
        self.old_stderr.flush()
        self.patcher.start()
        self.__redirected = True

    def unredirect(self):
        if not self.__redirected:
            return
        try:
            self.__stdout.flush()
            self.__stdout.close()
        except ValueError:
            # already closed?
            pass
        try:
            self.__stderr.flush()
            self.__stderr.close()
        except ValueError:
            # already closed?
            pass
        self.patcher.stop()

    def flush(self):
        if self.__redirected:
            try:
                self.__stdout.flush()
            except Exception:
                pass
            try:
                self.__stderr.flush()
            except Exception:
                pass


class TestsLoggingHandler(object):
    '''
    Simple logging handler which can be used to test if certain logging
    messages get emitted or not:

    .. code-block:: python

        with TestsLoggingHandler() as handler:
            # (...)               Do what ever you wish here
            handler.messages    # here are the emitted log messages

    '''
    def __init__(self, level=0, format='%(levelname)s:%(message)s'):
        self.level = level
        self.format = format
        self.activated = False
        self.prev_logging_level = None

    def activate(self):
        class Handler(logging.Handler):
            def __init__(self, level):
                logging.Handler.__init__(self, level)
                self.messages = []

            def emit(self, record):
                self.messages.append(self.format(record))

        self.handler = Handler(self.level)
        formatter = logging.Formatter(self.format)
        self.handler.setFormatter(formatter)
        logging.root.addHandler(self.handler)
        self.activated = True
        # Make sure we're running with the lowest logging level with our
        # tests logging handler
        current_logging_level = logging.root.getEffectiveLevel()
        if current_logging_level > logging.DEBUG:
            self.prev_logging_level = current_logging_level
            logging.root.setLevel(0)

    def deactivate(self):
        if not self.activated:
            return
        logging.root.removeHandler(self.handler)
        # Restore previous logging level if changed
        if self.prev_logging_level is not None:
            logging.root.setLevel(self.prev_logging_level)

    @property
    def messages(self):
        if not self.activated:
            return []
        return self.handler.messages

    def clear(self):
        self.handler.messages = []

    def __enter__(self):
        self.activate()
        return self

    def __exit__(self, type, value, traceback):
        self.deactivate()
        self.activated = False

    # Mimic some handler attributes and methods
    @property
    def lock(self):
        if self.activated:
            return self.handler.lock

    def createLock(self):
        if self.activated:
            return self.handler.createLock()

    def acquire(self):
        if self.activated:
            return self.handler.acquire()

    def release(self):
        if self.activated:
            return self.handler.release()


def relative_import(import_name, relative_from='../'):
    '''
    Update sys.path to include `relative_from` before importing `import_name`
    '''
    try:
        return __import__(import_name)
    except ImportError:
        previous_frame = inspect.getframeinfo(inspect.currentframe().f_back)
        sys.path.insert(
            0, os.path.realpath(
                os.path.join(
                    os.path.abspath(
                        os.path.dirname(previous_frame.filename)
                    ),
                    relative_from
                )
            )
        )
    return __import__(import_name)


class ForceImportErrorOn(object):
    '''
    This class is meant to be used in mock'ed test cases which require an
    ``ImportError`` to be raised.

    >>> import os.path
    >>> with ForceImportErrorOn('os.path'):
    ...     import os.path
    ...
    Traceback (most recent call last):
      File "<stdin>", line 2, in <module>
      File "salttesting/helpers.py", line 263, in __import__
        'Forced ImportError raised for {0!r}'.format(name)
    ImportError: Forced ImportError raised for 'os.path'
    >>>


    >>> with ForceImportErrorOn(('os', 'path')):
    ...     import os.path
    ...     sys.modules.pop('os', None)
    ...     from os import path
    ...
    <module 'os' from '/usr/lib/python2.7/os.pyc'>
    Traceback (most recent call last):
      File "<stdin>", line 4, in <module>
      File "salttesting/helpers.py", line 288, in __fake_import__
        name, ', '.join(fromlist)
    ImportError: Forced ImportError raised for 'from os import path'
    >>>


    >>> with ForceImportErrorOn(('os', 'path'), 'os.path'):
    ...     import os.path
    ...     sys.modules.pop('os', None)
    ...     from os import path
    ...
    Traceback (most recent call last):
      File "<stdin>", line 2, in <module>
      File "salttesting/helpers.py", line 281, in __fake_import__
        'Forced ImportError raised for {0!r}'.format(name)
    ImportError: Forced ImportError raised for 'os.path'
    >>>
    '''
    def __init__(self, *module_names):
        self.__module_names = {}
        for entry in module_names:
            if isinstance(entry, (list, tuple)):
                modname = entry[0]
                self.__module_names[modname] = set(entry[1:])
            else:
                self.__module_names[entry] = None
        self.__original_import = builtins.__import__
        self.patcher = patch.object(builtins, '__import__', self.__fake_import__)

    def patch_import_function(self):
        self.patcher.start()

    def restore_import_funtion(self):
        self.patcher.stop()

    def __fake_import__(self,
                        name,
                        globals_={} if six.PY2 else None,
                        locals_={} if six.PY2 else None,
                        fromlist=[] if six.PY2 else (),
                        level=-1 if six.PY2 else 0):
        if name in self.__module_names:
            importerror_fromlist = self.__module_names.get(name)
            if importerror_fromlist is None:
                raise ImportError(
                    'Forced ImportError raised for {0!r}'.format(name)
                )

            if importerror_fromlist.intersection(set(fromlist)):
                raise ImportError(
                    'Forced ImportError raised for {0!r}'.format(
                        'from {0} import {1}'.format(
                            name, ', '.join(fromlist)
                        )
                    )
                )
        return self.__original_import(name, globals_, locals_, fromlist, level)

    def __enter__(self):
        self.patch_import_function()
        return self

    def __exit__(self, exc_type, exc_value, traceback):
        self.restore_import_funtion()


class MockWraps(object):
    '''
    Helper class to be used with the mock library.
    To be used in the ``wraps`` keyword of ``Mock`` or ``MagicMock`` where you
    want to trigger a side effect for X times, and afterwards, call the
    original and un-mocked method.

    As an example:

    >>> def original():
    ...     print 'original'
    ...
    >>> def side_effect():
    ...     print 'side effect'
    ...
    >>> mw = MockWraps(original, 2, side_effect)
    >>> mw()
    side effect
    >>> mw()
    side effect
    >>> mw()
    original
    >>>

    '''
    def __init__(self, original, expected_failures, side_effect):
        self.__original = original
        self.__expected_failures = expected_failures
        self.__side_effect = side_effect
        self.__call_counter = 0

    def __call__(self, *args, **kwargs):
        try:
            if self.__call_counter < self.__expected_failures:
                if isinstance(self.__side_effect, types.FunctionType):
                    return self.__side_effect()
                raise self.__side_effect
            return self.__original(*args, **kwargs)
        finally:
            self.__call_counter += 1


def requires_network(only_local_network=False):
    '''
    Simple decorator which is supposed to skip a test case in case there's no
    network connection to the internet.
    '''
    def decorator(func):
        @functools.wraps(func)
        def wrapper(cls):
            has_local_network = False
            # First lets try if we have a local network. Inspired in
            # verify_socket
            try:
                pubsock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
                retsock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
                pubsock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
                pubsock.bind(('', 18000))
                pubsock.close()
                retsock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
                retsock.bind(('', 18001))
                retsock.close()
                has_local_network = True
            except socket.error:
                # I wonder if we just have IPV6 support?
                try:
                    pubsock = socket.socket(socket.AF_INET6, socket.SOCK_STREAM)
                    retsock = socket.socket(socket.AF_INET6, socket.SOCK_STREAM)
                    pubsock.setsockopt(
                        socket.SOL_SOCKET, socket.SO_REUSEADDR, 1
                    )
                    pubsock.bind(('', 18000))
                    pubsock.close()
                    retsock.setsockopt(
                        socket.SOL_SOCKET, socket.SO_REUSEADDR, 1
                    )
                    retsock.bind(('', 18001))
                    retsock.close()
                    has_local_network = True
                except socket.error:
                    # Let's continue
                    pass

            if only_local_network is True:
                if has_local_network is False:
                    # Since we're only supposed to check local network, and no
                    # local network was detected, skip the test
                    cls.skipTest('No local network was detected')
                return func(cls)

            # We are using the google.com DNS records as numerical IPs to avoid
            # DNS lookups which could greatly slow down this check
            for addr in ('173.194.41.198', '173.194.41.199', '173.194.41.200',
                         '173.194.41.201', '173.194.41.206', '173.194.41.192',
                         '173.194.41.193', '173.194.41.194', '173.194.41.195',
                         '173.194.41.196', '173.194.41.197'):
                sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
                try:
                    sock.settimeout(0.25)
                    sock.connect((addr, 80))
                    # We connected? Stop the loop
                    break
                except socket.error:
                    # Let's check the next IP
                    continue
                else:
                    cls.skipTest('No internet network connection was detected')
                finally:
                    sock.close()
            return func(cls)
        return wrapper
    return decorator


def with_system_user(username, on_existing='delete', delete=True, password=None, groups=None):
    '''
    Create and optionally destroy a system user to be used within a test
    case. The system user is created using the ``user`` salt module.

    The decorated testcase function must accept 'username' as an argument.

    :param username: The desired username for the system user.
    :param on_existing: What to do when the desired username is taken. The
      available options are:

      * nothing: Do nothing, act as if the user was created.
      * delete: delete and re-create the existing user
      * skip: skip the test case
    '''
    if on_existing not in ('nothing', 'delete', 'skip'):
        raise RuntimeError(
            'The value of \'on_existing\' can only be one of, '
            '\'nothing\', \'delete\' and \'skip\''
        )

    if not isinstance(delete, bool):
        raise RuntimeError(
            'The value of \'delete\' can only be \'True\' or \'False\''
        )

    def decorator(func):

        @functools.wraps(func)
        def wrap(cls):

            # Let's add the user to the system.
            log.debug('Creating system user {0!r}'.format(username))
            kwargs = {'timeout': 60, 'groups': groups}
            if salt.utils.platform.is_windows():
                kwargs.update({'password': password})
            create_user = cls.run_function('user.add', [username], **kwargs)
            if not create_user:
                log.debug('Failed to create system user')
                # The user was not created
                if on_existing == 'skip':
                    cls.skipTest(
                        'Failed to create system user {0!r}'.format(
                            username
                        )
                    )

                if on_existing == 'delete':
                    log.debug(
                        'Deleting the system user {0!r}'.format(
                            username
                        )
                    )
                    delete_user = cls.run_function(
                        'user.delete', [username, True, True]
                    )
                    if not delete_user:
                        cls.skipTest(
                            'A user named {0!r} already existed on the '
                            'system and re-creating it was not possible'
                            .format(username)
                        )
                    log.debug(
                        'Second time creating system user {0!r}'.format(
                            username
                        )
                    )
                    create_user = cls.run_function('user.add', [username], **kwargs)
                    if not create_user:
                        cls.skipTest(
                            'A user named {0!r} already existed, was deleted '
                            'as requested, but re-creating it was not possible'
                            .format(username)
                        )

            failure = None
            try:
                try:
                    return func(cls, username)
                except Exception as exc:  # pylint: disable=W0703
                    log.error(
                        'Running {0!r} raised an exception: {1}'.format(
                            func, exc
                        ),
                        exc_info=True
                    )
                    # Store the original exception details which will be raised
                    # a little further down the code
                    failure = sys.exc_info()
            finally:
                if delete:
                    delete_user = cls.run_function(
                        'user.delete', [username, True, True], timeout=60
                    )
                    if not delete_user:
                        if failure is None:
                            log.warning(
                                'Although the actual test-case did not fail, '
                                'deleting the created system user {0!r} '
                                'afterwards did.'.format(username)
                            )
                        else:
                            log.warning(
                                'The test-case failed and also did the removal'
                                ' of the system user {0!r}'.format(username)
                            )
                if failure is not None:
                    # If an exception was thrown, raise it
                    six.reraise(failure[0], failure[1], failure[2])
        return wrap
    return decorator


def with_system_group(group, on_existing='delete', delete=True):
    '''
    Create and optionally destroy a system group to be used within a test
    case. The system user is crated using the ``group`` salt module.

    The decorated testcase function must accept 'group' as an argument.

    :param group: The desired group name for the system user.
    :param on_existing: What to do when the desired username is taken. The
      available options are:

      * nothing: Do nothing, act as if the group was created
      * delete: delete and re-create the existing user
      * skip: skip the test case
    '''
    if on_existing not in ('nothing', 'delete', 'skip'):
        raise RuntimeError(
            'The value of \'on_existing\' can only be one of, '
            '\'nothing\', \'delete\' and \'skip\''
        )

    if not isinstance(delete, bool):
        raise RuntimeError(
            'The value of \'delete\' can only be \'True\' or \'False\''
        )

    def decorator(func):

        @functools.wraps(func)
        def wrap(cls):

            # Let's add the user to the system.
            log.debug('Creating system group {0!r}'.format(group))
            create_group = cls.run_function('group.add', [group])
            if not create_group:
                log.debug('Failed to create system group')
                # The group was not created
                if on_existing == 'skip':
                    cls.skipTest(
                        'Failed to create system group {0!r}'.format(group)
                    )

                if on_existing == 'delete':
                    log.debug(
                        'Deleting the system group {0!r}'.format(group)
                    )
                    delete_group = cls.run_function('group.delete', [group])
                    if not delete_group:
                        cls.skipTest(
                            'A group named {0!r} already existed on the '
                            'system and re-creating it was not possible'
                            .format(group)
                        )
                    log.debug(
                        'Second time creating system group {0!r}'.format(
                            group
                        )
                    )
                    create_group = cls.run_function('group.add', [group])
                    if not create_group:
                        cls.skipTest(
                            'A group named {0!r} already existed, was deleted '
                            'as requested, but re-creating it was not possible'
                            .format(group)
                        )

            failure = None
            try:
                try:
                    return func(cls, group)
                except Exception as exc:  # pylint: disable=W0703
                    log.error(
                        'Running {0!r} raised an exception: {1}'.format(
                            func, exc
                        ),
                        exc_info=True
                    )
                    # Store the original exception details which will be raised
                    # a little further down the code
                    failure = sys.exc_info()
            finally:
                if delete:
                    delete_group = cls.run_function('group.delete', [group])
                    if not delete_group:
                        if failure is None:
                            log.warning(
                                'Although the actual test-case did not fail, '
                                'deleting the created system group {0!r} '
                                'afterwards did.'.format(group)
                            )
                        else:
                            log.warning(
                                'The test-case failed and also did the removal'
                                ' of the system group {0!r}'.format(group)
                            )
                if failure is not None:
                    # If an exception was thrown, raise it
                    six.reraise(failure[0], failure[1], failure[2])
        return wrap
    return decorator


def with_system_user_and_group(username, group,
                               on_existing='delete', delete=True):
    '''
    Create and optionally destroy a system user and group to be used within a
    test case. The system user is crated using the ``user`` salt module, and
    the system group is created with the ``group`` salt module.

    The decorated testcase function must accept both the 'username' and 'group'
    arguments.

    :param username: The desired username for the system user.
    :param group: The desired name for the system group.
    :param on_existing: What to do when the desired username is taken. The
      available options are:

      * nothing: Do nothing, act as if the user was created.
      * delete: delete and re-create the existing user
      * skip: skip the test case
    '''
    if on_existing not in ('nothing', 'delete', 'skip'):
        raise RuntimeError(
            'The value of \'on_existing\' can only be one of, '
            '\'nothing\', \'delete\' and \'skip\''
        )

    if not isinstance(delete, bool):
        raise RuntimeError(
            'The value of \'delete\' can only be \'True\' or \'False\''
        )

    def decorator(func):

        @functools.wraps(func)
        def wrap(cls):

            # Let's add the user to the system.
            log.debug('Creating system user {0!r}'.format(username))
            create_user = cls.run_function('user.add', [username])
            log.debug('Creating system group {0!r}'.format(group))
            create_group = cls.run_function('group.add', [group])
            if not create_user:
                log.debug('Failed to create system user')
                # The user was not created
                if on_existing == 'skip':
                    cls.skipTest(
                        'Failed to create system user {0!r}'.format(
                            username
                        )
                    )

                if on_existing == 'delete':
                    log.debug(
                        'Deleting the system user {0!r}'.format(
                            username
                        )
                    )
                    delete_user = cls.run_function(
                        'user.delete', [username, True, True]
                    )
                    if not delete_user:
                        cls.skipTest(
                            'A user named {0!r} already existed on the '
                            'system and re-creating it was not possible'
                            .format(username)
                        )
                    log.debug(
                        'Second time creating system user {0!r}'.format(
                            username
                        )
                    )
                    create_user = cls.run_function('user.add', [username])
                    if not create_user:
                        cls.skipTest(
                            'A user named {0!r} already existed, was deleted '
                            'as requested, but re-creating it was not possible'
                            .format(username)
                        )
            if not create_group:
                log.debug('Failed to create system group')
                # The group was not created
                if on_existing == 'skip':
                    cls.skipTest(
                        'Failed to create system group {0!r}'.format(group)
                    )

                if on_existing == 'delete':
                    log.debug(
                        'Deleting the system group {0!r}'.format(group)
                    )
                    delete_group = cls.run_function('group.delete', [group])
                    if not delete_group:
                        cls.skipTest(
                            'A group named {0!r} already existed on the '
                            'system and re-creating it was not possible'
                            .format(group)
                        )
                    log.debug(
                        'Second time creating system group {0!r}'.format(
                            group
                        )
                    )
                    create_group = cls.run_function('group.add', [group])
                    if not create_group:
                        cls.skipTest(
                            'A group named {0!r} already existed, was deleted '
                            'as requested, but re-creating it was not possible'
                            .format(group)
                        )

            failure = None
            try:
                try:
                    return func(cls, username, group)
                except Exception as exc:  # pylint: disable=W0703
                    log.error(
                        'Running {0!r} raised an exception: {1}'.format(
                            func, exc
                        ),
                        exc_info=True
                    )
                    # Store the original exception details which will be raised
                    # a little further down the code
                    failure = sys.exc_info()
            finally:
                if delete:
                    delete_user = cls.run_function(
                        'user.delete', [username, True, True]
                    )
                    delete_group = cls.run_function('group.delete', [group])
                    if not delete_user:
                        if failure is None:
                            log.warning(
                                'Although the actual test-case did not fail, '
                                'deleting the created system user {0!r} '
                                'afterwards did.'.format(username)
                            )
                        else:
                            log.warning(
                                'The test-case failed and also did the removal'
                                ' of the system user {0!r}'.format(username)
                            )
                    if not delete_group:
                        if failure is None:
                            log.warning(
                                'Although the actual test-case did not fail, '
                                'deleting the created system group {0!r} '
                                'afterwards did.'.format(group)
                            )
                        else:
                            log.warning(
                                'The test-case failed and also did the removal'
                                ' of the system group {0!r}'.format(group)
                            )
                if failure is not None:
                    # If an exception was thrown, raise it
                    six.reraise(failure[0], failure[1], failure[2])
        return wrap
    return decorator


class WithTempfile(object):
    def __init__(self, **kwargs):
        self.create = kwargs.pop('create', True)
        if 'dir' not in kwargs:
            kwargs['dir'] = TMP
        if 'prefix' not in kwargs:
            kwargs['prefix'] = '__salt.test.'
        self.kwargs = kwargs

    def __call__(self, func):
        self.func = func
        return functools.wraps(func)(
            lambda testcase, *args, **kwargs: self.wrap(testcase, *args, **kwargs)  # pylint: disable=W0108
        )

    def wrap(self, testcase, *args, **kwargs):
        name = salt.utils.files.mkstemp(**self.kwargs)
        if not self.create:
            os.remove(name)
        try:
            return self.func(testcase, name, *args, **kwargs)
        finally:
            try:
                os.remove(name)
            except OSError:
                pass


with_tempfile = WithTempfile


class WithTempdir(object):
    def __init__(self, **kwargs):
        self.create = kwargs.pop('create', True)
        if 'dir' not in kwargs:
            kwargs['dir'] = TMP
        self.kwargs = kwargs

    def __call__(self, func):
        self.func = func
        return functools.wraps(func)(
            lambda testcase, *args, **kwargs: self.wrap(testcase, *args, **kwargs)  # pylint: disable=W0108
        )

    def wrap(self, testcase, *args, **kwargs):
        tempdir = tempfile.mkdtemp(**self.kwargs)
        if not self.create:
            os.rmdir(tempdir)
        try:
            return self.func(testcase, tempdir, *args, **kwargs)
        finally:
            shutil.rmtree(tempdir, ignore_errors=True)


with_tempdir = WithTempdir


def requires_system_grains(func):
    '''
    Function decorator which loads and passes the system's grains to the test
    case.
    '''
    @functools.wraps(func)
    def decorator(*args, **kwargs):
        if not hasattr(requires_system_grains, '__grains__'):
            import salt.config
            root_dir = tempfile.mkdtemp(dir=TMP)
            defaults = salt.config.DEFAULT_MINION_OPTS.copy()
            defaults.pop('conf_file')
            defaults.update({
                'root_dir': root_dir,
                'cachedir': 'cachedir',
                'sock_dir': 'sock',
                'pki_dir': 'pki',
                'log_file': 'logs/minion',
                'pidfile': 'pids/minion.pid'
            })
            opts = salt.config.minion_config(None, defaults=defaults)
            requires_system_grains.__grains__ = salt.loader.grains(opts)
            shutil.rmtree(root_dir, ignore_errors=True)
        kwargs['grains'] = requires_system_grains.__grains__
        return func(*args, **kwargs)
    return decorator


def requires_salt_modules(*names):
    '''
    Makes sure the passed salt module is available. Skips the test if not

    .. versionadded:: 0.5.2
    '''
    def decorator(caller):

        if inspect.isclass(caller):
            # We're decorating a class
            old_setup = getattr(caller, 'setUp', None)

            def setUp(self, *args, **kwargs):
                if old_setup is not None:
                    old_setup(self, *args, **kwargs)

                if not hasattr(self, 'run_function'):
                    raise RuntimeError(
                        '{0} does not have the \'run_function\' method which '
                        'is necessary to collect the loaded modules'.format(
                            self.__class__.__name__
                        )
                    )

                if not hasattr(requires_salt_modules, '__available_modules__'):
                    requires_salt_modules.__available_modules__ = set()

                _names = []
                for name in names:
                    if name not in requires_salt_modules.__available_modules__:
                        _names.append(name)

                if _names:
                    not_found_modules = self.run_function('runtests_helpers.modules_available', _names)
                    for name in _names:
                        if name not in not_found_modules:
                            requires_salt_modules.__available_modules__.add(name)
                    if not_found_modules:
                        if len(not_found_modules) == 1:
                            self.skipTest('Salt module {0!r} is not available'.format(not_found_modules[0]))
                        self.skipTest('Salt modules not available: {0!r}'.format(not_found_modules))
            caller.setUp = setUp
            return caller

        # We're simply decorating functions
        @functools.wraps(caller)
        def wrapper(cls):

            if not hasattr(cls, 'run_function'):
                raise RuntimeError(
                    '{0} does not have the \'run_function\' method which is '
                    'necessary to collect the loaded modules'.format(
                        cls.__class__.__name__
                    )
                )

            if not hasattr(requires_salt_modules, '__available_modules__'):
                requires_salt_modules.__available_modules__ = set()

            _names = []
            for name in names:
                if name not in requires_salt_modules.__available_modules__:
                    _names.append(name)

            if _names:
                not_found_modules = cls.run_function('runtests_helpers.modules_available', _names)
                for name in _names:
                    if name not in not_found_modules:
                        requires_salt_modules.__available_modules__.add(name)
                if not_found_modules:
                    if len(not_found_modules) == 1:
                        cls.skipTest('Salt module {0!r} is not available'.format(not_found_modules[0]))
                    cls.skipTest('Salt modules not available: {0!r}'.format(not_found_modules))
            return caller(cls)
        return wrapper
    return decorator


def skip_if_binaries_missing(*binaries, **kwargs):
    import salt.utils.path
    if len(binaries) == 1:
        if isinstance(binaries[0], (list, tuple, set, frozenset)):
            binaries = binaries[0]
    check_all = kwargs.pop('check_all', False)
    message = kwargs.pop('message', None)
    if kwargs:
        raise RuntimeError(
            'The only supported keyword argument is \'check_all\' and '
            '\'message\'. Invalid keyword arguments: {0}'.format(
                ', '.join(kwargs.keys())
            )
        )
    if check_all:
        for binary in binaries:
            if salt.utils.path.which(binary) is None:
                return skip(
                    '{0}The {1!r} binary was not found'.format(
                        message and '{0}. '.format(message) or '',
                        binary
                    )
                )
    elif salt.utils.path.which_bin(binaries) is None:
        return skip(
            '{0}None of the following binaries was found: {1}'.format(
                message and '{0}. '.format(message) or '',
                ', '.join(binaries)
            )
        )
    return _id


def skip_if_not_root(func):
    if not sys.platform.startswith('win'):
        if os.getuid() != 0:
            func.__unittest_skip__ = True
            func.__unittest_skip_why__ = 'You must be logged in as root to run this test'
    else:
        current_user = salt.utils.win_functions.get_current_user()
        if current_user != 'SYSTEM':
            if not salt.utils.win_functions.is_admin(current_user):
                func.__unittest_skip__ = True
                func.__unittest_skip_why__ = 'You must be logged in as an Administrator to run this test'
    return func


if sys.platform.startswith('win'):
    SIGTERM = signal.CTRL_BREAK_EVENT  # pylint: disable=no-member
else:
    SIGTERM = signal.SIGTERM


def collect_child_processes(pid):
    '''
    Try to collect any started child processes of the provided pid
    '''
    # Let's get the child processes of the started subprocess
    try:
        parent = psutil.Process(pid)
        if hasattr(parent, 'children'):
            children = parent.children(recursive=True)
        else:
            children = []
    except psutil.NoSuchProcess:
        children = []
    return children[::-1]  # return a reversed list of the children


def _terminate_process_list(process_list, kill=False, slow_stop=False):
    for process in process_list[:][::-1]:  # Iterate over a reversed copy of the list
        if not psutil.pid_exists(process.pid):
            process_list.remove(process)
            continue
        try:
            if not kill and process.status() == psutil.STATUS_ZOMBIE:
                # Zombie processes will exit once child processes also exit
                continue
            try:
                cmdline = process.cmdline()
            except psutil.AccessDenied:
                # OSX is more restrictive about the above information
                cmdline = None
            except OSError:
                cmdline = None
            if not cmdline:
                try:
                    cmdline = process.as_dict()
                except Exception:
                    cmdline = 'UNKNOWN PROCESS'
            if kill:
                log.info('Killing process(%s): %s', process.pid, cmdline)
                process.kill()
            else:
                log.info('Terminating process(%s): %s', process.pid, cmdline)
                try:
                    if slow_stop:
                        # Allow coverage data to be written down to disk
                        process.send_signal(SIGTERM)
                        try:
                            process.wait(2)
                        except psutil.TimeoutExpired:
                            if psutil.pid_exists(process.pid):
                                continue
                    else:
                        process.terminate()
                except OSError as exc:
                    if exc.errno not in (errno.ESRCH, errno.EACCES):
                        raise
            if not psutil.pid_exists(process.pid):
                process_list.remove(process)
        except psutil.NoSuchProcess:
            process_list.remove(process)


def terminate_process_list(process_list, kill=False, slow_stop=False):

    def on_process_terminated(proc):
        log.info('Process %s terminated with exit code: %s', getattr(proc, '_cmdline', proc), proc.returncode)

    # Try to terminate processes with the provided kill and slow_stop parameters
    log.info('Terminating process list. 1st step. kill: %s, slow stop: %s', kill, slow_stop)

    # Cache the cmdline since that will be inaccessible once the process is terminated
    for proc in process_list:
        try:
            cmdline = proc.cmdline()
        except (psutil.NoSuchProcess, psutil.AccessDenied):
            # OSX is more restrictive about the above information
            cmdline = None
        if not cmdline:
            try:
                cmdline = proc
            except (psutil.NoSuchProcess, psutil.AccessDenied):
                cmdline = '<could not be retrived; dead process: {0}>'.format(proc)
        proc._cmdline = cmdline
    _terminate_process_list(process_list, kill=kill, slow_stop=slow_stop)
    psutil.wait_procs(process_list, timeout=15, callback=on_process_terminated)

    if process_list:
        # If there's still processes to be terminated, retry and kill them if slow_stop is False
        log.info('Terminating process list. 2nd step. kill: %s, slow stop: %s', slow_stop is False, slow_stop)
        _terminate_process_list(process_list, kill=slow_stop is False, slow_stop=slow_stop)
        psutil.wait_procs(process_list, timeout=10, callback=on_process_terminated)

    if process_list:
        # If there's still processes to be terminated, just kill them, no slow stopping now
        log.info('Terminating process list. 3rd step. kill: True, slow stop: False')
        _terminate_process_list(process_list, kill=True, slow_stop=False)
        psutil.wait_procs(process_list, timeout=5, callback=on_process_terminated)

    if process_list:
        # In there's still processes to be terminated, log a warning about it
        log.warning('Some processes failed to properly terminate: %s', process_list)


def terminate_process(pid=None, process=None, children=None, kill_children=False, slow_stop=False):
    '''
    Try to terminate/kill the started processe
    '''
    children = children or []
    process_list = []

    def on_process_terminated(proc):
        if proc.returncode:
            log.info('Process %s terminated with exit code: %s', getattr(proc, '_cmdline', proc), proc.returncode)
        else:
            log.info('Process %s terminated', getattr(proc, '_cmdline', proc))

    if pid and not process:
        try:
            process = psutil.Process(pid)
            process_list.append(process)
        except psutil.NoSuchProcess:
            # Process is already gone
            process = None

    if kill_children:
        if process:
            if not children:
                children = collect_child_processes(process.pid)
            else:
                # Let's collect children again since there might be new ones
                children.extend(collect_child_processes(pid))
        if children:
            process_list.extend(children)

    if process_list:
        if process:
            log.info('Stopping process %s and respective children: %s', process, children)
        else:
            log.info('Terminating process list: %s', process_list)
        terminate_process_list(process_list, kill=slow_stop is False, slow_stop=slow_stop)
        if process and psutil.pid_exists(process.pid):
            log.warning('Process left behind which we were unable to kill: %s', process)


def terminate_process_pid(pid, only_children=False):
    children = []
    process = None

    # Let's begin the shutdown routines
    try:
        process = psutil.Process(pid)
        children = collect_child_processes(pid)
    except psutil.NoSuchProcess:
        log.info('No process with the PID %s was found running', pid)

    if only_children:
        return terminate_process(children=children, kill_children=True, slow_stop=True)
    return terminate_process(pid=pid, process=process, children=children, kill_children=True, slow_stop=True)


def repeat(caller=None, condition=True, times=5):
    '''
    Repeat a test X amount of times until the first failure.

    .. code-block:: python

        class MyTestCase(TestCase):

        @repeat
        def test_sometimes_works(self):
            pass
    '''
    if caller is None:
        return functools.partial(repeat, condition=condition, times=times)

    if isinstance(condition, bool) and condition is False:
        # Don't even decorate
        return caller
    elif callable(condition):
        if condition() is False:
            # Don't even decorate
            return caller

    if inspect.isclass(caller):
        attrs = [n for n in dir(caller) if n.startswith('test_')]
        for attrname in attrs:
            try:
                function = getattr(caller, attrname)
                if not inspect.isfunction(function) and not inspect.ismethod(function):
                    continue
                setattr(caller, attrname, repeat(caller=function, condition=condition, times=times))
            except Exception as exc:
                log.exception(exc)
                continue
        return caller

    @functools.wraps(caller)
    def wrap(cls):
        result = None
        for attempt in range(1, times+1):
            log.info('%s test run %d of %s times', cls, attempt, times)
            caller(cls)
        return cls
    return wrap


def http_basic_auth(login_cb=lambda username, password: False):
    '''
    A crude decorator to force a handler to request HTTP Basic Authentication

    Example usage:

    .. code-block:: python

        @http_basic_auth(lambda u, p: u == 'foo' and p == 'bar')
        class AuthenticatedHandler(tornado.web.RequestHandler):
            pass
    '''
    def wrapper(handler_class):
        def wrap_execute(handler_execute):
            def check_auth(handler, kwargs):

                auth = handler.request.headers.get('Authorization')

                if auth is None or not auth.startswith('Basic '):
                    # No username/password entered yet, we need to return a 401
                    # and set the WWW-Authenticate header to request login.
                    handler.set_status(401)
                    handler.set_header(
                        'WWW-Authenticate', 'Basic realm=Restricted')

                else:
                    # Strip the 'Basic ' from the beginning of the auth header
                    # leaving the base64-encoded secret
                    username, password = \
                        base64.b64decode(auth[6:]).split(':', 1)

                    if login_cb(username, password):
                        # Authentication successful
                        return
                    else:
                        # Authentication failed
                        handler.set_status(403)

                handler._transforms = []
                handler.finish()

            def _execute(self, transforms, *args, **kwargs):
                check_auth(self, kwargs)
                return handler_execute(self, transforms, *args, **kwargs)

            return _execute

        handler_class._execute = wrap_execute(handler_class._execute)
        return handler_class
    return wrapper


def generate_random_name(prefix, size=6):
    '''
    Generates a random name by combining the provided prefix with a randomly generated
    ascii string.

    .. versionadded:: 2018.3.0

    prefix
        The string to prefix onto the randomly generated ascii string.

    size
        The number of characters to generate. Default: 6.
    '''
    return prefix + ''.join(
        random.choice(string.ascii_uppercase + string.digits)
        for x in range(size)
    )


class Webserver(object):
    '''
    Starts a tornado webserver on 127.0.0.1 on a random available port

    USAGE:

    .. code-block:: python

        from tests.support.helpers import Webserver

        webserver = Webserver('/path/to/web/root')
        webserver.start()
        webserver.stop()
    '''
    def __init__(self,
                 root=None,
                 port=None,
                 wait=5,
                 handler=None):
        '''
        root
            Root directory of webserver. If not passed, it will default to the
            location of the base environment of the integration suite's file
            roots (tests/integration/files/file/base/)

        port
            Port on which to listen. If not passed, a random one will be chosen
            at the time the start() function is invoked.

        wait : 5
            Number of seconds to wait for the socket to be open before raising
            an exception

        handler
            Can be used to use a subclass of tornado.web.StaticFileHandler,
            such as when enforcing authentication with the http_basic_auth
            decorator.
        '''
        if port is not None and not isinstance(port, six.integer_types):
            raise ValueError('port must be an integer')

        if root is None:
            root = os.path.join(FILES, 'file', 'base')
        try:
            self.root = os.path.realpath(root)
        except AttributeError:
            raise ValueError('root must be a string')

        self.port = port
        self.wait = wait
        self.handler = handler \
            if handler is not None \
            else tornado.web.StaticFileHandler
        self.web_root = None

    def target(self):
        '''
        Threading target which stands up the tornado application
        '''
        self.ioloop = tornado.ioloop.IOLoop()
        self.ioloop.make_current()
        self.application = tornado.web.Application(
            [(r'/(.*)', self.handler, {'path': self.root})])
        self.application.listen(self.port)
        self.ioloop.start()

    @property
    def listening(self):
        if self.port is None:
            return False
        sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        return sock.connect_ex(('127.0.0.1', self.port)) == 0

    def url(self, path):
        '''
        Convenience function which, given a file path, will return a URL that
        points to that path. If the path is relative, it will just be appended
        to self.web_root.
        '''
        if self.web_root is None:
            raise RuntimeError('Webserver instance has not been started')
        err_msg = 'invalid path, must be either a relative path or a path ' \
                  'within {0}'.format(self.root)
        try:
            relpath = path \
                if not os.path.isabs(path) \
                else os.path.relpath(path, self.root)
            if relpath.startswith('..' + os.sep):
                raise ValueError(err_msg)
            return '/'.join((self.web_root, relpath))
        except AttributeError:
            raise ValueError(err_msg)

    def start(self):
        '''
        Starts the webserver
        '''
        if self.port is None:
            self.port = get_unused_localhost_port()

        self.web_root = 'http://127.0.0.1:{0}'.format(self.port)

        self.server_thread = threading.Thread(target=self.target)
        self.server_thread.daemon = True
        self.server_thread.start()

        for idx in range(self.wait + 1):
            if self.listening:
                break
            if idx != self.wait:
                time.sleep(1)
        else:
            raise Exception(
                'Failed to start tornado webserver on 127.0.0.1:{0} within '
                '{1} seconds'.format(self.port, self.wait)
            )

    def stop(self):
        '''
        Stops the webserver
        '''
        self.ioloop.add_callback(self.ioloop.stop)
        self.server_thread.join()


def win32_kill_process_tree(pid, sig=signal.SIGTERM, include_parent=True,
        timeout=None, on_terminate=None):
    '''
    Kill a process tree (including grandchildren) with signal "sig" and return
    a (gone, still_alive) tuple.  "on_terminate", if specified, is a callabck
    function which is called as soon as a child terminates.
    '''
    if pid == os.getpid():
        raise RuntimeError("I refuse to kill myself")
    try:
        parent = psutil.Process(pid)
    except psutil.NoSuchProcess:
        log.debug("PID not found alive: %d", pid)
        return ([], [])
    children = parent.children(recursive=True)
    if include_parent:
        children.append(parent)
    for p in children:
        p.send_signal(sig)
    gone, alive = psutil.wait_procs(children, timeout=timeout,
                                    callback=on_terminate)
    return (gone, alive)


def this_user():
    '''
    Get the user associated with the current process.
    '''
    if salt.utils.platform.is_windows():
        return salt.utils.win_functions.get_current_user(with_domain=False)
    return pwd.getpwuid(os.getuid())[0]


def dedent(text, linesep=os.linesep):
    '''
    A wrapper around textwrap.dedent that also sets line endings.
    '''
    linesep = salt.utils.stringutils.to_unicode(linesep)
    unicode_text = textwrap.dedent(salt.utils.stringutils.to_unicode(text))
    clean_text = linesep.join(unicode_text.splitlines())
    if unicode_text.endswith(u'\n'):
        clean_text += linesep
    if not isinstance(text, six.text_type):
        return salt.utils.stringutils.to_bytes(clean_text)
    return clean_text