Refactor code that decides which logfile to use, if any.

Adds unit tests.

nova/log.py

@@ -112,6 +112,15 @@ def _dictify_context(context):
         context = context.to_dict()
     return context
 
+def _get_binary_name():
+    return os.path.basename(inspect.stack()[-1][1])
+
+def get_log_file_path(binary=None):
+    if FLAGS.logfile:
+        return FLAGS.logfile
+    if FLAGS.logdir:
+        binary = binary or _get_binary_name()
+        return '%s.log' % (os.path.join(FLAGS.logdir, binary),)
 
 def basicConfig():
     logging.basicConfig()
@@ -125,12 +134,8 @@ def basicConfig():
         syslog = SysLogHandler(address='/dev/log')
         syslog.setFormatter(_formatter)
         logging.root.addHandler(syslog)
-    if FLAGS.logfile or FLAGS.logdir:
+    logpath = get_log_file_path()
-        if FLAGS.logfile:
+    if logpath:
-            logfile = FLAGS.logfile
-        else:
-            binary = os.path.basename(inspect.stack()[-1][1])
-            logpath = '%s.log' % (os.path.join(FLAGS.logdir, binary),)
         logfile = FileHandler(logpath)
         logfile.setFormatter(_formatter)
         logging.root.addHandler(logfile)

nova/tests/test_log.py

@@ -46,6 +46,27 @@ class RootLoggerTestCase(test.TestCase):
         self.assert_(True)  # didn't raise exception
 
 
+class LogHandlerTestCase(test.TestCase):
+    def test_log_path_logdir(self):
+        self.flags(logdir='/some/path')
+        self.assertEquals(log.get_log_file_path(binary='foo-bar'),
+                         '/some/path/foo-bar.log')
+
+    def test_log_path_logfile(self):
+        self.flags(logfile='/some/path/foo-bar.log')
+        self.assertEquals(log.get_log_file_path(binary='foo-bar'),
+                         '/some/path/foo-bar.log')
+
+    def test_log_path_none(self):
+        self.assertIsNone(log.get_log_file_path(binary='foo-bar'))
+
+    def test_log_path_logfile_overrides_logdir(self):
+        self.flags(logdir='/some/other/path',
+                   logfile='/some/path/foo-bar.log')
+        self.assertEquals(log.get_log_file_path(binary='foo-bar'),
+                         '/some/path/foo-bar.log')
+
+
 class NovaFormatterTestCase(test.TestCase):
     def setUp(self):
         super(NovaFormatterTestCase, self).setUp()