Add tests for timeout

* test_timeout_value which checks that every timeout call is done
  with the configuration value
* test_timeout_warning which checks that a warning is raised when
  the timeout raises an exception

Author: mx-psi

disk/datadog_checks/disk/disk.py

@@ -78,6 +78,7 @@ def check(self, instance):
 
             # Get disk metrics here to be able to exclude on total usage
             try:
+                self.log.debug("Check %s", part.mountpoint)
                 disk_usage = timeout(self._timeout)(psutil.disk_usage)(part.mountpoint)
             except TimeoutException:
                 self.log.warning(

disk/tests/test_unit.py

@@ -9,10 +9,11 @@
 from six import iteritems
 
 from datadog_checks.base.utils.platform import Platform
+from datadog_checks.base.utils.timeout import TimeoutException
 from datadog_checks.disk import Disk
 
 from .common import DEFAULT_DEVICE_BASE_NAME, DEFAULT_DEVICE_NAME, DEFAULT_FILE_SYSTEM, DEFAULT_MOUNT_POINT
-from .mocks import MockDiskMetrics, mock_blkid_output
+from .mocks import MockDiskMetrics, MockPart, mock_blkid_output
 
 
 def test_default_options():
@@ -212,3 +213,61 @@ def test_blkid_cache_file_contains_no_labels(
     c.check(instance_blkid_cache_file_no_label)
     for metric in chain(gauge_metrics, rate_metrics):
         aggregator.assert_metric(metric, tags=['device:/dev/sda1', 'device_name:sda1'])
+
+
+@pytest.mark.usefixtures('psutil_mocks')
+def test_timeout_config(aggregator, gauge_metrics, rate_metrics):
+    """Test timeout configuration value is used on every timeout on the check."""
+
+    # Arbitrary value
+    TIMEOUT_VALUE = 42
+    instance = {'timeout': TIMEOUT_VALUE}
+    c = Disk('disk', {}, [instance])
+
+    # Mock timeout version
+    def no_timeout(fun):
+        return lambda *args: fun(args)
+
+    with mock.patch('psutil.disk_partitions', return_value=[MockPart()]), mock.patch(
+        'datadog_checks.disk.disk.timeout', return_value=no_timeout
+    ) as mock_timeout:
+        c.check(instance)
+
+    mock_timeout.assert_called_with(TIMEOUT_VALUE)
+
+
+@pytest.mark.usefixtures('psutil_mocks')
+def test_timeout_warning(aggregator, gauge_metrics, rate_metrics):
+    """Test a warning is raised when there is a Timeout exception."""
+
+    # Raise exception for "/faulty" mountpoint
+    def faulty_timeout(fun):
+        def f(mountpoint):
+            if mountpoint == "/faulty":
+                raise TimeoutException
+            else:
+                return fun(mountpoint)
+
+        return f
+
+    c = Disk('disk', {}, [{}])
+    c.log = mock.MagicMock()
+    m = MockDiskMetrics()
+    m.total = 0
+
+    with mock.patch('psutil.disk_partitions', return_value=[MockPart(), MockPart(mountpoint="/faulty")]), mock.patch(
+        'psutil.disk_usage', return_value=m, __name__='disk_usage'
+    ), mock.patch('datadog_checks.disk.disk.timeout', return_value=faulty_timeout):
+        c.check({})
+
+    # Check that the warning is called once for the faulty disk
+    c.log.warning.assert_called_once()
+
+    for name in gauge_metrics:
+        aggregator.assert_metric(name, count=0)
+
+    for name in rate_metrics:
+        aggregator.assert_metric_has_tag(name, 'device:{}'.format(DEFAULT_DEVICE_NAME))
+        aggregator.assert_metric_has_tag(name, 'device_name:{}'.format(DEFAULT_DEVICE_BASE_NAME))
+
+    aggregator.assert_all_metrics_covered()