Poet::Log -- Poet logging
# In a conf file... log: defaults: level: info output: poet.log layout: "%d{dd/MMM/yyyy:HH:mm:ss.SS} [%p] %c - %m - %F:%L - %P%n" category: CHI: level: debug output: chi.log layout: "%d{dd/MMM/yyyy:HH:mm:ss.SS} %m - %P%n" MyApp::Foo: output: stdout # In a script... use Poet::Script qw($log); # In a module... use Poet qw($log); # In a component... my $log = $m->log; # For an arbitrary category... my $log = Poet::Log->get_logger(category => 'MyApp::Bar'); # then... $log->error("an error occurred"); $log->debugf("arguments are: %s", \@_) if $log->is_debug();
Poet uses Log::Any and Log::Log4perl for logging, with simplified configuration for the common case.
Log::Any is a logging abstraction that allows CPAN modules to log without knowing about which logging framework is in use. It supports standard logging methods ($log->debug, $log->is_debug) along with sprintf variants ($log->debugf).
$log->debug
$log->is_debug
$log->debugf
Log4perl is a powerful logging package that provides just about any logging-related feature you'd want. One of its only drawbacks is its somewhat cumbersome configuration. So, we provide a way to configure Log4perl simply through Poet configuration if you just want common features.
Note: Log4perl is not a strict dependency for Poet. Log messages will simply not get logged until you install it or until you modify logging for your app.
The configurations below can go in any Poet conf file, e.g. local.cfg or global/log.cfg.
local.cfg
global/log.cfg
Here's a simple configuration that caches everything to logs/poet.log at info level. This is also the default if no configuration is present.
logs/poet.log
info
log: defaults: level: info output: poet.log layout: %d{dd/MMM/yyyy:HH:mm:ss.SS} [%p] %c - %m - %F:%L - %P%n
Here's a more involved configuration that maintains the same default, but adds several categories that are logged differently:
log: defaults: level: info output: poet.log layout: "%d{dd/MMM/yyyy:HH:mm:ss.SS} [%p] %c - %m - %F:%L - %P%n" category: CHI: level: debug output: chi.log layout: "%d{dd/MMM/yyyy:HH:mm:ss.SS} %m - %P%n" MyApp::Foo: output: stdout
For the default and for each category, you can specify three different settings:
level - one of the valid log4perl levels (fatal, error, warn, info, debug, trace)
output - can be a relative filename (which will be placed in the Poet log directory), an absolute filename, or the special names "stdout" or "stderr"
layout - a valid log4perl PatternLayout string.
If a setting isn't defined for a specific category then it falls back to the default. In this example, MyApp::Foo will inherit the default level and layout.
MyApp::Foo
Notice that we use '::' instead of '.' to specify hierarchical category names, because '.' would interfere with Poet::Conf dot notation.
Finally, if you must use a full Log4perl configuration file, you can specify it this way:
log: log4perl_conf: /path/to/log4perl.conf
In a script (log category will be 'main'):
use Poet::Script qw($log);
In a module MyApp::Foo (log category will be 'MyApp::Foo'):
use Poet qw($log);
In a component /foo/bar (log category will be 'Mason::Component::foo::bar'):
/foo/bar
my $log = $m->log;
Manually for an arbitrary log category:
my $log = Poet::Log->get_logger(category => 'Some::Category'); # or my $log = MyApp::Log->get_logger(category => 'Some::Category');
$log->error("an error occurred"); $log->debugf("arguments are: %s", \@_) if $log->is_debug();
See Log::Any|Log::Any for more details.
Log::Any|Log::Any
These methods are not intended to be called externally, but may be useful to override or modify with method modifiers in subclasses. Their APIs will be kept as stable as possible.
Called once when the Poet environment is initialized. By default, initializes log4perl with the results of "generate_log4perl_config" and then calls Log::Any::Adapter->set('Log4perl'). You can modify this to initialize log4perl in your own way, or use a different Log::Any adapter, or use a completely different logging system.
Log::Any::Adapter->set('Log4perl')
Returns a log4perl config string based on Poet configuration. You can modify this to construct and return your own config.
Poet
Jonathan Swartz <swartz@pobox.com>
This software is copyright (c) 2012 by Jonathan Swartz.
This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.
To install Poet, copy and paste the appropriate command in to your terminal.
cpanm
cpanm Poet
CPAN shell
perl -MCPAN -e shell install Poet
For more information on module installation, please visit the detailed CPAN module installation guide.