TracLogging

last updated 16-04-2021 · author: trac

Trac Logging¶

Trac supports logging of system messages using Python's logging module.

Logging is configured in the "[logging"] section of TracIni.

Supported Logging Methods¶

The log method is set using the "[logging log_type"] option, which accepts the following values:

*'none* - Suppress all log messages.
**file** - Log messages to a file, specified with the "[logging log_file"] option. Relative paths for \log_file\ are resolved relative to the environment \log\ directory.
**stderr** - Output log entries to console (tracd only).
**syslog** - (UNIX) Send log messages to the local syslogd via named pipe \/dev/log\. By default, syslog will write them to the \/var/log/messages\ file.
**eventlog** - (Windows) Use the system's NT Event Log.

Log Levels¶

The verbosity level of logged messages can be set using the "[logging log_level"] option. The log level defines the minimum level of urgency required for a message to be logged, and those levels are:

**CRITICAL** - Log only the most critical (typically fatal) errors.
**ERROR** - Log failures, bugs and errors.
**WARN** - Log warnings, non-interrupting events.
**INFO** - Diagnostic information, log information about all processing.
**DEBUG** - Trace messages, profiling, etc.

Additionally, you can enable logging of SQL statements at debug level. This is turned off by default, as it's very verbose. Set "[trac debug_sql = yes"] to activate.

Log Format¶

The output format for log entries can be specified in the "[logging log_format"] option. The format is a string which can contain any of the Python logging Formatter variables. Additionally, the following Trac-specific variables can be used:

**$(basename)s** - The environment directory name.
**$(path)s** - The absolute path of the environment directory.
**$(project)s** - The originating project's name.

Note that variables are identified using a dollar sign (\$(...)s\) instead of percent sign (\%(...)s\).

The default format is:

log_format = Trac[$(module)s] $(levelname)s: $(message)s

In a multi-project environment where all logs are sent to the same place (e.g. \syslog\), it makes sense to add the project name. In this example we use \basename\ since that can generally be used to identify a project:

log_format = Trac[$(basename)s:$(module)s] $(levelname)s: $(message)s