Allowing logger to be extended with different handlers

[Ryan J Ollos]

Adding a LoggerManager Component and a ILoggingHandlerProvider interface would allow new ​handlers to be added through plugins. It should also be possible to eliminate some redundant definitions of log types in log.py and admin/web_ui.py, and provide a cleaner definition of log levels.

One handler that will be of immediate use is the addition of MockLoggingHandler in test.py, taken from ​SO:1049375/121694.

[Ryan J Ollos]

Narrowing focus for 1.1.4.

[Ryan J Ollos]

Milestone renamed

[Ryan J Ollos]

Narrowing focus for milestone:1.2. Please move ticket to milestone:1.2 if you intend to fix it.

[Ryan J Ollos]

The changes in this ticket can also include the addition of LogRecordFilter proposed in #7820. The change was not included in that ticket because it would have resulted in an API change.

class LogRecordFilter(logging.Filter):
    def __init__(self, path, basename, project):
        super(LogRecordFilter, self).__init__()
        self.path = path
        self.basename = basename
        self.project = project

    def filter(self, record):
        record.path = self.path
        record.basename = self.basename
        record.project = self.project

        return True

[Ryan J Ollos]

Since #7820 allows the logger to be configured from a file, rather than adding an extension point I think we can just use ​StreamHandler in EnvironmentStub, and have EnvironmentStub utilize StreamHandler to log to a stream buffer target that we can make assertions again.

[Ryan J Ollos]

Proposed changes in log:rjollos.git:t11874_mock_logger.

I'd like to avoid use of StringIO.StringIO after #12046, however I'm having some trouble with that.

Use of io.StringIO results in:

Traceback (most recent call last):
  File "/usr/local/Cellar/python/2.7.12/Frameworks/Python.framework/Versions/2.7/lib/python2.7/logging/__init__.py", line 882, in emit
    stream.write(fs % msg)
TypeError: unicode argument expected, got 'str'
Logged from file main.py, line 191

Use of io.BytesIO results in:

Traceback (most recent call last):
  File "/usr/local/Cellar/python/2.7.12/Frameworks/Python.framework/Versions/2.7/lib/python2.7/logging/__init__.py", line 882, in emit
    stream.write(fs % msg)
TypeError: 'unicode' does not have the buffer interface
Logged from file main.py, line 176

[Ryan J Ollos]

Replying to Ryan J Ollos:

Proposed changes in log:rjollos.git:t11874_mock_logger.

I'd like to avoid use of StringIO.StringIO after #12046, however I'm having some trouble with that.

Changed to use BufferingHandler in [81740a12/rjollos.git].

[Ryan J Ollos]

[ab85dc14/rjollos.git] changes EnvironmentStub.log_messages to return a list of tuples with (level_name, message).

[Jun Omae]

Looks good to me. However I'm not sure about adding self.assertEqual('DEBUG', level) in [ab85dc14/rjollos.git].

It seems that test case confirms Can't authenticate using ... in log messages from rjollos.git/trac/web/main.py@ab85dc14:174-176#L169​. I think the test case should be this:

trac/web/tests/main.py

@@ -120 +120 @@
                          self.request_dispatcher.authenticate(self.req))
         self.assertEqual(1, len(self.req.chrome['warnings']))
         expected = "Can't authenticate using RaisingAuthenticator: "
-        level = None
         for level, message in self.env.log_messages:
             if expected in message.split('\n'):
+                self.assertEqual('ERROR', level)
                 break
         else:
-            self.assertEqual('DEBUG', level)
             self.fail("Expected log message not found: \"%s\"" % expected)
 
     def test_authenticate_once(self):

[Ryan J Ollos]

Thanks for spotting that error. Changes committed to trunk in r15129, including patch from comment:15. Additional changes in r15130. I'll continue with related work on logging system in #7820.

The Travis CI build failures on OSX were resolved by clearing the caches.