collectd-openstack-plugins/collectd_ceilometer/tests/common/test_config.py

# -*- coding: utf-8 -*-

# Copyright 2010-2011 OpenStack Foundation
# Copyright (c) 2015 Intel Corporation.
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
#      http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.
"""Configuration tests"""

import abc
from unittest import TestCase

import mock
import six

from collectd_ceilometer.common import settings


def config_module(
        values, units=None, libvirt_meter=False,
        module_name="collectd_ceilometer.ceilometer.plugin"):
    children = [config_value(key, value)
                for key, value in six.iteritems(values)]
    if units:
        children.append(config_units(units))
    return config_node('MODULE', children=children, value=module_name)


def config_units(units):
    children = [config_value('UNIT', key, value)
                for key, value in six.iteritems(units)]
    return config_node('UNITS', children)


def config_node(key, children, value=None):
    "Create a mocked collectd config node having given children and value"
    return mock.create_autospec(
        spec=MockCollectdConfig, spec_set=True, instance=True,
        children=tuple(children), key=key, values=(value,))


def config_value(key, *values):
    "Create a mocked collectd config node having given multiple values"
    return mock.create_autospec(
        spec=MockCollectdConfig, spec_set=True, instance=True,
        children=tuple(), key=key, values=values)


class MockCollectdConfig(object):

    @abc.abstractproperty
    def children(self):
        pass

    @abc.abstractproperty
    def key(self):
        pass

    @abc.abstractproperty
    def values(self):
        pass


class TestConfig(TestCase):
    """Test configuration reader"""

    @property
    def default_values(self):
        return dict(
            BATCH_SIZE=1,
            OS_AUTH_URL='https://test-auth.url.tld/test',
            CEILOMETER_URL_TYPE='internalURL',
            CEILOMETER_TIMEOUT=1000,
            OS_USERNAME='tester',
            OS_PASSWORD='testpasswd',
            OS_TENANT_NAME='service',
            LIBVIRT_METER_ENABLED=False)

    @mock.patch.object(settings, 'LOGGER', autospec=True)
    def test_default_configuration(self, LOGGER):
        """Test valid configuration"""

        node = config_module(values=self.default_values)
        config = settings.Config._decorated()

        # read default configuration
        config.read(node)

        # compare the configuration values with the default values
        for key, value in six.iteritems(self.default_values):
            self.assertEqual(value, getattr(config, key))

        # test configuration change
        self.assertEqual(1, config.BATCH_SIZE)
        config.read(config_module(values=dict(BATCH_SIZE=10)))
        self.assertEqual(10, config.BATCH_SIZE)
        LOGGER.error.assert_not_called()

    def test_singleton(self):
        """Test config singleton class

        Verify that the TypeError exception is raised when the instance
        of the Config class is created by user.
        """

        with self.assertRaises(TypeError) as exc:
            # must rise a TypeError as the singleton class cannot
            # be created by the user and can be accessed only
            # by its instance() method
            settings.Config()  # flake8: noqa

        self.assertEqual(
            six.text_type(exc.exception),
            'Singleton must be accessed through instance() method')

    @mock.patch.object(settings, 'LOGGER', autospec=True)
    def test_invalid_value(self, LOGGER):
        """Test invalid value

        Test string instead of int
        """
        values = self.default_values
        values["BATCH_SIZE"] = "xyz"
        node = config_module(values=values)
        config = settings.Config._decorated()

        config.read(node)

        LOGGER.error.assert_called_once_with(
            'Invalid value "xyz" for configuration parameter "BATCH_SIZE"')
        self.assertEqual(1, config.BATCH_SIZE)

    @mock.patch.object(settings, 'LOGGER', autospec=True)
    def test_unknown_parameter(self, LOGGER):
        """Test unknown parameter

        Test configuration parameter which is not known (expected)
        """
        values = self.default_values
        values["UNKNOWN"] = "xyz"
        node = config_module(values=values)
        config = settings.Config._decorated()

        config.read(node)

        LOGGER.error.assert_called_with(
            'Unknown configuration parameter "%s"', 'UNKNOWN')
        self.assertFalse(hasattr(node, 'UNKNOWN'))

    @mock.patch.object(settings, 'LOGGER', autospec=True)
    def test_missing_value(self, LOGGER):
        """Test configuration node vithout value"""

        node = config_module(values=self.default_values)
        # remove values from some node
        for child in node.children:
            if child.key == 'OS_AUTH_URL':
                child.values = tuple()
                break
        config = settings.Config._decorated()

        config.read(node)

        LOGGER.error.assert_has_calls([
            mock.call('No configuration value found for "%s"', "OS_AUTH_URL"),
            mock.call('Configuration parameter %s not set.', "OS_AUTH_URL"),
            mock.call('Collectd plugin will not work properly')])

    @mock.patch.object(settings, 'LOGGER', autospec=True)
    def test_user_units(self, LOGGER):
        """Test configuration with user defined units"""

        node = config_module(
            values=self.default_values,
            units={'age': 'years',
                   'star.distance': 'LY',
                   'star.temperature': 'K'})
        config = settings.Config._decorated()

        config.read(node)

        LOGGER.error.assert_not_called()
        self.assertEqual('years', config.unit('age', None))
        self.assertEqual('LY', config.unit('star', 'distance'))
        self.assertEqual('K', config.unit('star', 'temperature'))
        self.assertEqual('None', config.unit('monty', None))
        self.assertEqual('None', config.unit('monty', 'python'))

    @mock.patch.object(settings, 'LOGGER', autospec=True)
    def test_user_units_invalid(self, LOGGER):
        """Test invalid user defined units

        The unit node contains three values (two are expected)
        """

        node = config_module(values=self.default_values,
                             units=dict(age='years'))
        # make some unit entry invalid
        for child in node.children:
            if child.key == 'UNITS':
                child.children[0].values = (1, 2, 3)
                break
        config = settings.Config._decorated()

        config.read(node)

        self.assertEqual('None', config.unit('age', None))
        LOGGER.error.assert_called_with(
            'Invalid unit configuration: unit "1" "2" "3"')

    @mock.patch.object(settings, 'LOGGER', autospec=True)
    def test_user_units_invalid_invalid_node(self, LOGGER):
        """Test invalid node with units configuration"""

        node = config_module(values=self.default_values,
                             units=dict(age='years'))
        # make some unit entry invalid
        for child in node.children:
            if child.key == 'UNITS':
                child.children[0].key = 'NOT_UNITS'
                break
        config = settings.Config._decorated()

        config.read(node)

        LOGGER.error.assert_called_with(
            'Invalid unit configuration: %s', "NOT_UNITS")
        self.assertEqual('None', config.unit('age', None))

    def test_libvirt_meter_enabled(self):
        """Test configuration change when enabling the libvirt meter

        Set-up: Create a node and set the LIBVIRT_METER_ENABLED value.
        Test: Read the node and check the 'LIBVIRT_METER_ENABLED value.
        Expected behaviour: When configured this value will return True.
        """

        node = config_module(values=dict(LIBVIRT_METER_ENABLED=True))
        config = settings.Config._decorated()

        config.read(config_module(values=dict(LIBVIRT_METER_ENABLED=True)))
        self.assertEqual(True, config.LIBVIRT_METER_ENABLED)

    @mock.patch.object(settings, 'LOGGER', autospec=True)
    def test_libvirt_meter_default_config(self, LOGGER):
        """Test default configuration for enabling the libvirt meter

        Set-up: Create a default node with no alternative configurations set
        Test: Read the defaults of this node.
        Expected behaviour: The default value for LIBVIRT_METER_ENABLED is
                            false.
        """

        node = config_module(values=self.default_values)
        config = settings.Config._decorated()

        for child in node.children:
            if child.key == 'LIBVIRT_METER_ENABLED':
                config.libvirt_meter = getattr(config, child.key)

        config.read(node)

        self.assertEqual(False, config.libvirt_meter)
        LOGGER.error.assert_not_called()