systemctl-mqtt/tests/test_mqtt.py

# systemctl-mqtt - MQTT client triggering shutdown on systemd-based systems
#
# Copyright (C) 2020 Fabian Peter Hammerle <fabian@hammerle.me>
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <https://www.gnu.org/licenses/>.

import logging
import unittest.mock

import pytest
from paho.mqtt.client import MQTTMessage

import systemctl_mqtt

# pylint: disable=protected-access


@pytest.mark.parametrize("mqtt_host", ["mqtt-broker.local"])
@pytest.mark.parametrize("mqtt_port", [1833])
@pytest.mark.parametrize("mqtt_topic_prefix", ["systemctl/host", "system/command"])
def test__run(mqtt_host, mqtt_port, mqtt_topic_prefix):
    with unittest.mock.patch(
        "paho.mqtt.client.Client"
    ) as mqtt_client_mock, unittest.mock.patch(
        "systemctl_mqtt._mqtt_on_message"
    ) as message_handler_mock:
        systemctl_mqtt._run(
            mqtt_host=mqtt_host,
            mqtt_port=mqtt_port,
            mqtt_username=None,
            mqtt_password=None,
            mqtt_topic_prefix=mqtt_topic_prefix,
        )
    assert mqtt_client_mock.call_count == 1  # .assert_called_once requires python>=v3.6
    init_args, init_kwargs = mqtt_client_mock.call_args
    assert not init_args
    assert len(init_kwargs) == 1
    settings = init_kwargs["userdata"]
    assert isinstance(settings, systemctl_mqtt._Settings)
    assert mqtt_topic_prefix + "/poweroff" in settings.mqtt_topic_action_mapping
    assert not mqtt_client_mock().username_pw_set.called
    mqtt_client_mock().tls_set.assert_called_once_with(ca_certs=None)
    mqtt_client_mock().connect.assert_called_once_with(host=mqtt_host, port=mqtt_port)
    mqtt_client_mock().socket().getpeername.return_value = (mqtt_host, mqtt_port)
    mqtt_client_mock().on_connect(mqtt_client_mock(), settings, {}, 0)
    mqtt_client_mock().subscribe.assert_called_once_with(
        mqtt_topic_prefix + "/poweroff"
    )
    mqtt_client_mock().on_message(mqtt_client_mock(), settings, "message")
    assert message_handler_mock.call_count == 1
    mqtt_client_mock().loop_forever.assert_called_once_with()


@pytest.mark.parametrize("mqtt_host", ["mqtt-broker.local"])
@pytest.mark.parametrize("mqtt_port", [1833])
@pytest.mark.parametrize("mqtt_username", ["me"])
@pytest.mark.parametrize("mqtt_password", [None, "secret"])
@pytest.mark.parametrize("mqtt_topic_prefix", ["systemctl/host"])
def test__run_authentication(
    mqtt_host, mqtt_port, mqtt_username, mqtt_password, mqtt_topic_prefix
):
    with unittest.mock.patch("paho.mqtt.client.Client") as mqtt_client_mock:
        systemctl_mqtt._run(
            mqtt_host=mqtt_host,
            mqtt_port=mqtt_port,
            mqtt_username=mqtt_username,
            mqtt_password=mqtt_password,
            mqtt_topic_prefix=mqtt_topic_prefix,
        )
    assert mqtt_client_mock.call_count == 1
    init_args, init_kwargs = mqtt_client_mock.call_args
    assert not init_args
    assert set(init_kwargs.keys()) == {"userdata"}
    mqtt_client_mock().username_pw_set.assert_called_once_with(
        username=mqtt_username, password=mqtt_password,
    )


@pytest.mark.parametrize("mqtt_host", ["mqtt-broker.local"])
@pytest.mark.parametrize("mqtt_port", [1833])
@pytest.mark.parametrize("mqtt_password", ["secret"])
def test__run_authentication_missing_username(mqtt_host, mqtt_port, mqtt_password):
    with unittest.mock.patch("paho.mqtt.client.Client"):
        with pytest.raises(ValueError):
            systemctl_mqtt._run(
                mqtt_host=mqtt_host,
                mqtt_port=mqtt_port,
                mqtt_username=None,
                mqtt_password=mqtt_password,
                mqtt_topic_prefix="prefix",
            )


@pytest.mark.parametrize("mqtt_topic_prefix", ["system/command"])
@pytest.mark.parametrize("payload", [b"", b"junk"])
def test__mqtt_on_message_poweroff(caplog, mqtt_topic_prefix: str, payload: bytes):
    mqtt_topic = mqtt_topic_prefix + "/poweroff"
    message = MQTTMessage(topic=mqtt_topic.encode())
    message.payload = payload
    settings = systemctl_mqtt._Settings(mqtt_topic_prefix=mqtt_topic_prefix)
    action_mock = unittest.mock.MagicMock()
    settings.mqtt_topic_action_mapping[mqtt_topic] = action_mock  # functools.partial
    with caplog.at_level(logging.DEBUG):
        systemctl_mqtt._mqtt_on_message(
            None, settings, message,
        )
    assert len(caplog.records) == 3
    assert caplog.records[0].levelno == logging.DEBUG
    assert caplog.records[0].message == (
        "received topic={} payload={!r}".format(mqtt_topic, payload)
    )
    assert caplog.records[1].levelno == logging.DEBUG
    assert caplog.records[1].message.startswith(
        "executing action {!r}".format(action_mock)
    )
    assert caplog.records[2].levelno == logging.DEBUG
    assert caplog.records[2].message.startswith(
        "completed action {!r}".format(action_mock)
    )
    action_mock.assert_called_once_with()


@pytest.mark.parametrize(
    ("topic", "payload"), [("system/poweroff", b""), ("system/poweroff", "payload"),],
)
def test__mqtt_on_message_ignored(
    caplog, topic: str, payload: bytes,
):
    message = MQTTMessage(topic=topic.encode())
    message.payload = payload
    settings = systemctl_mqtt._Settings(mqtt_topic_prefix="system/command")
    settings.mqtt_topic_action_mapping = {}  # provoke KeyError on access
    with caplog.at_level(logging.DEBUG):
        systemctl_mqtt._mqtt_on_message(
            None, settings, message,
        )
    assert len(caplog.records) == 2
    assert caplog.records[0].levelno == logging.DEBUG
    assert caplog.records[0].message == (
        "received topic={} payload={!r}".format(topic, payload)
    )
    assert caplog.records[1].levelno == logging.WARNING
    assert caplog.records[1].message == "unexpected topic {}".format(topic)


@pytest.mark.parametrize(
    ("topic", "payload"), [("system/command/poweroff", b"")],
)
def test__mqtt_on_message_ignored_retained(
    caplog, topic: str, payload: bytes,
):
    message = MQTTMessage(topic=topic.encode())
    message.payload = payload
    message.retain = True
    settings = systemctl_mqtt._Settings(mqtt_topic_prefix="system/command")
    settings.mqtt_topic_action_mapping = {}  # provoke KeyError on access
    with caplog.at_level(logging.DEBUG):
        systemctl_mqtt._mqtt_on_message(
            None, settings, message,
        )
    assert len(caplog.records) == 2
    assert caplog.records[0].levelno == logging.DEBUG
    assert caplog.records[0].message == (
        "received topic={} payload={!r}".format(topic, payload)
    )
    assert caplog.records[1].levelno == logging.INFO
    assert caplog.records[1].message == "ignoring retained message"