syslog unable to filter based on priority.

[cgskumar77]

Hi,

My rsyslog is unable to apply selectors to the priority portion of the logs sent by boost.log.

I'm using boost_1_79 with native syslog on Ubuntu 18.04.

I'm following instructions from https://www.boost.org/doc/libs/1_79_0/libs/log/doc/html/log/detailed/sink_backends.html#log.detailed.sink_backends.syslog

Here is the code snippet:

// Create a backend
boost::shared_ptr< sinks::syslog_backend > backend(new sinks::syslog_backend(
        keywords::facility = sinks::syslog::user,               1
        keywords::use_impl = sinks::syslog::native              2
));

// Set the straightforward level translator for the "Severity" attribute of type int
backend->set_severity_mapper(sinks::syslog::direct_severity_mapping< int >("Severity"));

// . . .
BOOST_LOG_SEV(lg, sinks::syslog::alert) << "An alert message.";

Here is my /etc/rsyslog.d/50-default.conf: user.alert -/var/log/user.log

This doesn't write a record in user.log file unless I change the selector to user.*. I have also tried to explicitly define a custom mapping as well with the same results.

However, I don't have any such problems if I use the loggerutility from the command line to write logs. This suggests that the logs from boost.log doesn't have the right severity in them. Is that possible? Or I have something wrong in my code although it is just cut and paste from the tutorial mentioned above.

Any ideas on how to resolve this?

Thanks, Senthil.

[Lastique]

You should check the type of the severity level attribute in your logger lg. You're specifying int in the severity mapping function (direct_severity_mapping< int >), so if the severity attribute value has a different type the mapping function won't be able to extract it from the log record and will return the default value, which is info.

[cgskumar77]

Thank you very much, Andrey. The following change helped:

-    src::logger lg;
+    src::severity_logger<int> lg { keywords::severity = sinks::syslog::error };

I should have read https://www.boost.org/doc/libs/1_79_0/libs/log/doc/html/log/detailed/sources.html#log.detailed.sources.severity_level_logger

Thanks, Senthil.