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NAME

MooseX::Daemonize - Role for daemonizing your Moose based application

VERSION

version 0.22

SYNOPSIS

package My::Daemon;
use Moose;

with qw(MooseX::Daemonize);

# ... define your class ....

after start => sub {
    my $self = shift;
    return unless $self->is_daemon;
    # your daemon code here ...
};

# then in your script ...

my $daemon = My::Daemon->new_with_options();

my ($command) = @{$daemon->extra_argv}
defined $command || die "No command specified";

$daemon->start   if $command eq 'start';
$daemon->status  if $command eq 'status';
$daemon->restart if $command eq 'restart';
$daemon->stop    if $command eq 'stop';

warn($daemon->status_message);
exit($daemon->exit_code);

DESCRIPTION

Often you want to write a persistent daemon that has a pid file, and responds appropriately to Signals. This module provides a set of basic roles as an infrastructure to do that.

WARNING

The maintainers of this module now recommend using Daemon::Control instead.

CAVEATS

When going into background MooseX::Daemonize closes all open file handles. This may interfere with you logging because it may also close the log file handle you want to write to. To prevent this you can either defer opening the log file until after start. Alternatively, use can use the 'dont_close_all_files' option either from the command line or in your .sh script.

Assuming you want to use Log::Log4perl for example you could expand the MooseX::Daemonize example above like this.

after start => sub {
    my $self = shift;
    return unless $self->is_daemon;
    Log::Log4perl->init(\$log4perl_config);
    my $logger = Log::Log4perl->get_logger();
    $logger->info("Daemon started");
    # your daemon code here ...
};

ATTRIBUTES

This list includes attributes brought in from other roles as well we include them here for ease of documentation. All of these attributes are settable though MooseX::Getopt's command line handling, with the exception of is_daemon.

progname Path::Class::Dir | Str

The name of our daemon, defaults to $package_name =~ s/::/_/;

pidbase Path::Class::Dir | Str

The base for our PID, defaults to /var/run/

basedir Path::Class::Dir | Str

The directory we chdir to; defaults to /.

pidfile MooseX::Daemonize::Pid::File | Str

The file we store our PID in, defaults to $pidbase/$progname.pid

foreground Bool

If true, the process won't background. Useful for debugging. This option can be set via Getopt's -f.

no_double_fork Bool

If true, the process will not perform the typical double-fork, which is extra added protection from your process accidentally acquiring a controlling terminal. More information can be found by Googling "double fork daemonize".

ignore_zombies Bool

If true, the process will not clean up zombie processes. Normally you don't want this.

dont_close_all_files Bool

If true, the objects open filehandles will not be closed when daemonized. Normally you don't want this.

is_daemon Bool

If true, the process is the backgrounded daemon process, if false it is the parent process. This is useful for example in an after 'start' = sub { }> block.

NOTE: This option is explicitly not available through MooseX::Getopt.

stop_timeout

Number of seconds to wait for the process to stop, before trying harder to kill it. Defaults to 2 seconds.

These are the internal attributes, which are not available through MooseX::Getopt.

exit_code Int
status_message Str

METHODS

Daemon Control Methods

These methods can be used to control the daemon behavior. Every effort has been made to have these methods DWIM (Do What I Mean), so that you can focus on just writing the code for your daemon.

Extending these methods is best done with the Moose method modifiers, such as before, after and around.

start

Setup a pidfile, fork, then setup the signal handlers.

stop

Stop the process matching the pidfile, and unlinks the pidfile.

restart

Literally this is:

$self->stop();
$self->start();
status
shutdown

Pidfile Handling Methods

init_pidfile

This method will create a MooseX::Daemonize::Pid::File object and tell it to store the PID in the file $pidbase/$progname.pid.

check

This checks to see if the daemon process is currently running by checking the pidfile.

get_pid

Returns the PID of the daemon process.

save_pid

Write the pidfile.

remove_pid

Removes the pidfile.

Signal Handling Methods

setup_signals

Setup the signal handlers, by default it only sets up handlers for SIGINT and SIGHUP. If you wish to add more signals just use the after method modifier and add them.

handle_sigint

Handle a INT signal, by default calls $self-stop()>

handle_sighup

Handle a HUP signal. By default calls $self-restart()>

Exit Code Methods

These are overridable constant methods used for setting the exit code.

OK

Returns 0.

ERROR

Returns 1.

Introspection

meta()

The meta() method from Class::MOP::Class

DEPENDENCIES

Moose, MooseX::Getopt, MooseX::Types::Path::Class and POSIX

INCOMPATIBILITIES

Obviously this will not work on Windows.

SEE ALSO

Daemon::Control, Proc::Daemon, Daemon::Generic

THANKS

Mike Boyko, Matt S. Trout, Stevan Little, Brandon Black, Ash Berlin and the #moose denizens

Some bug fixes sponsored by Takkle Inc.

SUPPORT

Bugs may be submitted through the RT bug tracker (or [email protected]).

There is also a mailing list available for users of this distribution, at http://lists.perl.org/list/moose.html.

There is also an irc channel available for users of this distribution, at #moose on irc.perl.org.

AUTHORS

CONTRIBUTORS

COPYRIGHT AND LICENCE

This software is copyright (c) 2007 by Chris Prather.

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.