[PATCH] Make syslog facility and socket configurable

[Sebastian Klemke <packet@…>]

To filter trac log entries and store them in a separate log file with syslog-type logging, the syslog facility must be configurable. Otherwise, trac log entries cannot be distinguished from other log entries using the same facility. Using file-type logging is not an option for me, as I don't know how to safely rotate the resulting log files.

Therefore, I wrote a patch to configure the syslog facility and the syslog socket using the new options log_facility and log_socket for syslog-type logging. log_facility is needed to distinguish trac log entries from other application's log entries. log_socket is needed for operating systems where the syslog socket is not named /dev/log.

[Sebastian Klemke <packet@…>]

Patch to add log_socket and log_facility options. Applies to trunk@11822

[Christian Boos]

Have you investigated if and how it would be possible to pass this extra information via the ​logging.config module? Given that beyond the basics, the logging module can be configured in a very extensive way, I think it would make more sense to offer this extra level of configuration via a dedicated configuration file rather than by extending the Trac logging API itself.

Besides, another possibility for you would be to specify the use of a ​RotatingFileHandler (also via this logging.config file).

[Sebastian Klemke <packet@…>]

Thank you for your feedback. I did not investigate this option, but will try if time permits. It seems that another trac patch is required to use logging.config. I will try to implement logging.config as a new log_type with a log_config option for the filename of the config file and see what can be done with it.

[Sebastian Klemke <packet@…>]

Patch introducing logging.config support. Applies to source:trunk@11822​

[Sebastian Klemke <packet@…>]

Example log configuration

[Sebastian Klemke <packet@…>]

I wrote another patch adding logging.config support. It adds a new log_type config and a new option log_config for the configuration file. The patch has some rough edges:

• It prevents environment initialization if configuration file is missing or defective
• I had to remove the _trac_handler attribute from the logger (seems to be unused)
• There seems to be no way of determining the used handler. Therefore I return None for the handler, effectively preventing flush() in Environment.shutdown()
• Keyword substitution of $(path)s, $(basename)s and $(project)s is not possible for the new log type config

[Sebastian Klemke <packet@…>]

Concerning RotatingFileHandler: I doubt it would work with multiple mod_wsgi processes.

[Christian Boos]

Looks like good start! Unfortunately I won't be able to review your patch until end of next week, so I'd welcome any other TracTeam member to pick it up from there.

[Ryan J Ollos]

Closing as a duplicate of #7820. A note has been added to #7820 to investigate the integration of the patches in this ticket.

[Ryan J Ollos]

Replying to Sebastian Klemke <packet@…>:

I wrote another patch adding logging.config support. It adds a new log_type config and a new option log_config for the configuration file. The patch has some rough edges:

Patch is being integrated as part of #7820, but I thought it appropriate to reply to these comments.

• It prevents environment initialization if configuration file is missing or defective

The exception handling path is the same as for the Environment needs upgrade error. I considered trapping the exception in Environment.setup_log​, but we'd have to choose a default logger in that case and the proper choice isn't clear to me. Alternatively we could try to trap the exception and add a warning to the request, but the changes look fairly extensive and I'm not sure it's worth the effort. Feedback welcome.

• I had to remove the _trac_handler attribute from the logger (seems to be unused)
• There seems to be no way of determining the used handler. Therefore I return None for the handler, effectively preventing flush() in Environment.shutdown()

From a cursory glance at the Python source, it looks like the loggers are held in WeakValueDictionary, which I assume is so they get automatically cleaned up.

• Keyword substitution of $(path)s, $(basename)s and $(project)s is not possible for the new log type config

I made some modifications in #7820 so that the keyword substitution is handled for log type config.