Add keyword arg 'log_stdout' to utils.execute()

This adds the keyword argument 'log_stdout' (Boolean) to utils.execute().
If set to True, it will log the stdout returned by executing the
command. By default, it is True.

This argument is used in ipa's (ironic-python-agent) copy of execute(),
and is being added here in preparation for changing ipa to use this
library's execute().

The docstrings associated with utils.execute() were updated to reflect
the copy in ipa.

Change-Id: I44148c6e9150c7afd3de7b0b59bedb4983d9a6a7
Partial-Bug: 1587199

ironic_lib/tests/test_utils.py

@@ -188,6 +188,32 @@ grep foo
                 'foo', run_as_root=True,
                 root_helper=CONF.ironic_lib.root_helper)
 
+    @mock.patch.object(utils, 'LOG', autospec=True)
+    def _test_execute_with_log_stdout(self, log_mock, log_stdout=None):
+        with mock.patch.object(processutils, 'execute') as execute_mock:
+            execute_mock.return_value = ('stdout', 'stderr')
+            if log_stdout is not None:
+                utils.execute('foo', log_stdout=log_stdout)
+            else:
+                utils.execute('foo')
+            execute_mock.assert_called_once_with('foo')
+            name, args, kwargs = log_mock.debug.mock_calls[1]
+            if log_stdout is False:
+                self.assertEqual(2, log_mock.debug.call_count)
+                self.assertNotIn('stdout', args[0])
+            else:
+                self.assertEqual(3, log_mock.debug.call_count)
+                self.assertIn('stdout', args[0])
+
+    def test_execute_with_log_stdout_default(self):
+        self._test_execute_with_log_stdout()
+
+    def test_execute_with_log_stdout_true(self):
+        self._test_execute_with_log_stdout(log_stdout=True)
+
+    def test_execute_with_log_stdout_false(self):
+        self._test_execute_with_log_stdout(log_stdout=False)
+
 
 class MkfsTestCase(test_base.BaseTestCase):
 

ironic_lib/utils.py

@@ -46,13 +46,21 @@ LOG = logging.getLogger(__name__)
 def execute(*cmd, **kwargs):
     """Convenience wrapper around oslo's execute() method.
 
-    :param cmd: Passed to processutils.execute.
+    Executes and logs results from a system command. See docs for
-    :param use_standard_locale: True | False. Defaults to False. If set to
+    oslo_concurrency.processutils.execute for usage.
-                                True, execute command with standard locale
+
+    :param \*cmd: positional arguments to pass to processutils.execute()
+    :param use_standard_locale: keyword-only argument. True | False.
+                                Defaults to False. If set to True,
+                                execute command with standard locale
                                 added to environment variables.
+    :param log_stdout: keyword-only argument. True | False. Defaults
+                       to True. If set to True, logs the output.
+    :param \*\*kwargs: keyword arguments to pass to processutils.execute()
     :returns: (stdout, stderr) from process execution
-    :raises: UnknownArgumentError
+    :raises: UnknownArgumentError on receiving unknown arguments
     :raises: ProcessExecutionError
+    :raises: OSError
     """
 
     use_standard_locale = kwargs.pop('use_standard_locale', False)
@@ -61,6 +69,8 @@ def execute(*cmd, **kwargs):
         env['LC_ALL'] = 'C'
         kwargs['env_variables'] = env
 
+    log_stdout = kwargs.pop('log_stdout', True)
+
     # If root_helper config is not specified, no commands are run as root.
     run_as_root = kwargs.get('run_as_root', False)
     if run_as_root:
@@ -72,7 +82,8 @@ def execute(*cmd, **kwargs):
     result = processutils.execute(*cmd, **kwargs)
     LOG.debug('Execution completed, command line is "%s"',
               ' '.join(map(str, cmd)))
-    LOG.debug('Command stdout is: "%s"' % result[0])
+    if log_stdout:
+        LOG.debug('Command stdout is: "%s"' % result[0])
     LOG.debug('Command stderr is: "%s"' % result[1])
     return result