Haraka has built-in logging (see API docs below) and support for log plugins.
Contains settings for log level, timestamps, and format. See the example log.ini file for examples.
The loglevel file provides a finger-friendly way to change the loglevel on the CLI. Use it like so:
echo DEBUG > config/loglevel. When the level in log.ini is set and the loglevel file is present, the loglevel file wins. During runtime, whichever was edited most recently wins.
Logging conventions within Haraka
This section pertains to the built in logging. For log plugins like (haraka-plugin-syslog), refer to the plugin's docs.
The logline by default will be in the form of:
[level] [uuid] [origin] message
Where origin is "core" or the name of the plugin which triggered the message, and "uuid" is the ID of the connection associated with the message.
When calling a log method on logger, you should provide the plugin object and the connection object anywhere in the arguments to the log method.
logger.logdebug("i like turtles", plugin, connection);
Will yield, for example,
[DEBUG] [7F1C820F-DC79-4192-9AA6-5307354B20A6] [dnsbl] i like turtles
If you call the log method on the connection object, you can forego the connection as argument:
connection.logdebug("turtles all the way down", plugin);
and similarly for the log methods on the plugin object:
plugin.logdebug("he just really likes turtles", connection);
failing to provide a connection and/or plugin object will leave the default values in the log (currently "core").
This is implemented by testing for argument type in the logger.js log* method. objects-as-arguments are then sniffed to try to determine if they're a connection or plugin instance.
The logfmt format is also supported and can be enabled by changing the format
logfmt in the
config/log.ini file which will
start logging in the following format below.
level=PROTOCOL uuid=9FF7F70E-5D57-435A-AAD9-EA069B6159D9.1 source=core message="S: 354 go ahead, make my day"
Any objects you pass through will also be appeneded to the log line as key=value and will look like this:
level=NOTICE uuid=9FF7F70E-5D57-435A-AAD9-EA069B6159D9.1 source=core message=disconnect ip=127.0.0.1 rdns=Unknown helo=3h2dnz8a0if relay=N early=N esmtp=N tls=N pipe=N errors=0 txns=1 rcpts=1/0/0 msgs=1/0/0 bytes=222 lr="" time=0.052
You can find out more about logfmt here: https://brandur.org/logfmt