[gitmo/MooseX-Daemonize.git] / lib / MooseX / Daemonize.pm

package MooseX::Daemonize;
use strict;    # because Kwalitee is pedantic
use Moose::Role;

our $VERSION = 0.01;
use Carp;
use Proc::Daemon;

use File::Flock;
use File::Slurp;

with qw(MooseX::Getopt);

has progname => (
    isa      => 'Str',
    is       => 'ro',
    lazy     => 1,
    required => 1,
    default  => sub {
        ( my $name = lc $_[0]->meta->name ) =~ s/::/_/g;
        return $name;
    },
);

has basedir => (
    isa     => 'Str',
    is      => 'ro',
    lazy    => 1,
    default => sub { return '/' },
);

has pidbase => (
    isa => 'Str',
    is  => 'ro',

    #    required => 1,
    lazy    => 1,
    default => sub { return '/var/run' },
);

has pidfile => (
    isa      => 'Str',
    is       => 'ro',
    lazy     => 1,
    required => 1,
    default  => sub {
        die 'Cannot write to ' . $_[0]->pidbase unless -w $_[0]->pidbase;
        $_[0]->pidbase . '/' . $_[0]->progname . '.pid';
    },
);

has foreground => (
    metaclass   => 'Getopt',
    cmd_aliases => ['f'],
    isa         => 'Bool',
    is          => 'ro',
    default     => sub { 0 },
);

sub check {
    my ($self) = @_;
    if ( my $pid = $self->get_pid ) {
        my $prog = $self->progname;
        if ( CORE::kill 0 => $pid ) {
            croak "$prog already running ($pid).";
        }
        carp "$prog not running but found pid ($pid)."
          . "Perhaps the pid file (@{ [$self->pidfile] }) is stale?";
        return 1;
    }
    return 0;
}

sub daemonize {
    my ($self) = @_;
    Proc::Daemon::Init;
}

sub start {
    my ($self) = @_;
    return if $self->check;

    $self->daemonize unless $self->foreground;

    # Avoid 'stdin reopened for output' warning with newer perls
    ## no critic
    open( NULL, '/dev/null' );
    <NULL> if (0);
    ## use critic
    
    # Change to basedir
    chdir $self->basedir;
    
    $self->save_pid;
    $self->setup_signals;
    return $$;
}

sub save_pid {
    my ($self) = @_;
    my $pidfile = $self->pidfile;
    lock( $pidfile, undef, 'nonblocking' )
      or croak "Could not lock PID file $pidfile: $!";
    write_file( $pidfile, "$$\n" );
    unlock($pidfile);
    return;
}

sub remove_pid {
    my ($self) = @_;
    my $pidfile = $self->pidfile;
    lock( $pidfile, undef, 'nonblocking' )
      or croak "Could not lock PID file $pidfile: $!";
    unlink($pidfile);
    unlock($pidfile);
    return;
}

sub get_pid {
    my ($self) = @_;
    my $pidfile = $self->pidfile;
    return unless -e $pidfile;
    chomp( my $pid = read_file($pidfile) );
    return $pid;
}

sub stop {
    my ( $self, %args ) = @_;
    my $pid = $self->get_pid;
    $self->_kill($pid) unless $self->foreground();
    $self->remove_pid;
    return 1 if $args{no_exit};
    exit;
}

sub restart {
    my ($self) = @_;
    $self->stop( noexit => 1 );
    $self->start();
}

sub setup_signals {
    my ($self) = @_;
    $SIG{INT} = sub { $self->handle_sigint; };
    $SIG{HUP} = sub { $self->handle_sighup };
}

sub handle_sigint { $_[0]->stop; }
sub handle_sighup { $_[0]->restart; }

sub _kill {
    confess "_kill isn't public" unless caller eq __PACKAGE__;
    my ( $self, $pid ) = @_;
    return unless $pid;
    unless ( CORE::kill 0 => $pid ) {

        # warn "$pid already appears dead.";
        return;
    }

    if ( $pid eq $$ ) {

        # warn "$pid is us! Can't commit suicied.";
        return;
    }

    CORE::kill( 2, $pid );    # Try SIGINT
    sleep(2) if CORE::kill( 0, $pid );

    unless ( CORE::kill 0 => $pid or $!{EPERM} ) {    # IF it is still running
        CORE::kill( 15, $pid );                       # try SIGTERM
        sleep(2) if CORE::kill( 0, $pid );
    }

    unless ( CORE::kill 0 => $pid or $!{EPERM} ) {    # IF it is still running
        CORE::kill( 9, $pid );                        # finally try SIGKILL
        sleep(2) if CORE::kill( 0, $pid );
    }

    unless ( CORE::kill 0 => $pid or $!{EPERM} ) {    # IF it is still running
        carp "$pid doesn't seem to want to die.";     # AHH EVIL DEAD!
    }

    return;
}

1;
__END__

=head1 NAME

MooseX::Daemonize - provides a Role that daemonizes your Moose based application.


=head1 VERSION

This document describes MooseX::Daemonize version 0.0.1


=head1 SYNOPSIS

    package FileMaker;
    use Moose;
    with qw(MooseX::Daemonize);

    sub create_file {
        my ( $self, $file ) = @_;
        open( FILE, ">$file" ) || die;
        close(FILE);
    }

    no Moose;

    # then in the main package ... 
    
    my $daemon = FileMaker->new();
    $daemon->start();
    $daemon->create_file($file);
    $daemon->stop();
     
=head1 DESCRIPTION

Often you want to write a persistant daemon that has a pid file, and responds appropriately to Signals. 
This module helps provide the basic infrastructure to do that.

=head1 ATTRIBUTES

=over

=item progname Str

The name of our daemon, defaults to $0

=item pidbase Str

The base for our bid, defaults to /var/run/$progname

=item pidfile Str

The file we store our PID in, defaults to /var/run/$progname/ 

=item foreground Bool

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

=back

=head1 METHODS 

=over

=item check()

Check to see if an instance is already running.

=item start()

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

=item stop()

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

=item restart()

Litterally 

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

=item daemonize()

Calls C<Proc::Daemon::Init> to daemonize this process. 

=item kill($pid)

Kills the process for $pid. This will try SIGINT, and SIGTERM before falling back to SIGKILL and finally giving up.

=item setup_signals()

Setup the signal handlers, by default it only sets up handlers for SIGINT and SIGHUP

=item handle_sigint()

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

=item handle_sighup()

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

=item get_pid

Lookup the pid from our pidfile.

=item save_pid

Save the current pid in our pidfile

=item remove_pid

Delete our pidfile

=item meta()

The C<meta()> method from L<Class::MOP::Class>

=back

=head1 DEPENDENCIES

=for author to fill in:
    A list of all the other modules that this module relies upon,
    including any restrictions on versions, and an indication whether
    the module is part of the standard Perl distribution, part of the
    module's distribution, or must be installed separately. ]

Obviously L<Moose>, also L<Carp>, L<Proc::Daemon>, L<File::Flock>, L<File::Slurp>

=head1 INCOMPATIBILITIES

=for author to fill in:
    A list of any modules that this module cannot be used in conjunction
    with. This may be due to name conflicts in the interface, or
    competition for system or program resources, or due to internal
    limitations of Perl (for example, many modules that use source code
    filters are mutually incompatible).

None reported.


=head1 BUGS AND LIMITATIONS

=for author to fill in:
    A list of known problems with the module, together with some
    indication Whether they are likely to be fixed in an upcoming
    release. Also a list of restrictions on the features the module
    does provide: data types that cannot be handled, performance issues
    and the circumstances in which they may arise, practical
    limitations on the size of data sets, special cases that are not
    (yet) handled, etc.

No bugs have been reported.

Please report any bugs or feature requests to
C<bug-acme-dahut-call@rt.cpan.org>, or through the web interface at
L<http://rt.cpan.org>.

=head1 SEE ALSO

L<Proc::Daemon>, L<Daemon::Generic>, L<MooseX::Getopt>

=head1 AUTHOR

Chris Prather  C<< <perigrin@cpan.org> >>


=head1 LICENCE AND COPYRIGHT

Copyright (c) 2007, Chris Prather C<< <perigrin@cpan.org> >>. All rights reserved.

This module is free software; you can redistribute it and/or
modify it under the same terms as Perl itself. See L<perlartistic>.


=head1 DISCLAIMER OF WARRANTY

BECAUSE THIS SOFTWARE IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY
FOR THE SOFTWARE, TO THE EXTENT PERMITTED BY APPLICABLE LAW. EXCEPT WHEN
OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES
PROVIDE THE SOFTWARE "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER
EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE
ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE SOFTWARE IS WITH
YOU. SHOULD THE SOFTWARE PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL
NECESSARY SERVICING, REPAIR, OR CORRECTION.

IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR
REDISTRIBUTE THE SOFTWARE AS PERMITTED BY THE ABOVE LICENCE, BE
LIABLE TO YOU FOR DAMAGES, INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL,
OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE
THE SOFTWARE (INCLUDING BUT NOT LIMITED TO LOSS OF DATA OR DATA BEING
RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD PARTIES OR A
FAILURE OF THE SOFTWARE TO OPERATE WITH ANY OTHER SOFTWARE), EVEN IF
SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF
SUCH DAMAGES.
Commit	Line	Data
a4952679	1	package MooseX::Daemonize;
a392fa53	2	use strict; # because Kwalitee is pedantic
a4952679	3	use Moose::Role;
	4
	5	our $VERSION = 0.01;
	6	use Carp;
	7	use Proc::Daemon;
a392fa53	8
a4952679	9	use File::Flock;
	10	use File::Slurp;
	11
	12	with qw(MooseX::Getopt);
	13
	14	has progname => (
a392fa53	15	isa => 'Str',
	16	is => 'ro',
	17	lazy => 1,
	18	required => 1,
	19	default => sub {
	20	( my $name = lc $_[0]->meta->name ) =~ s/::/_/g;
	21	return $name;
	22	},
a4952679	23	);
a4952679	24
24a6a660	25	has basedir => (
	26	isa => 'Str',
	27	is => 'ro',
	28	lazy => 1,
	29	default => sub { return '/' },
	30	);
	31
a4952679	32	has pidbase => (
2361a590	33	isa => 'Str',
	34	is => 'ro',
	35
	36	# required => 1,
	37	lazy => 1,
	38	default => sub { return '/var/run' },
a4952679	39	);
	40
	41	has pidfile => (
	42	isa => 'Str',
	43	is => 'ro',
	44	lazy => 1,
	45	required => 1,
3543c999	46	default => sub {
	47	die 'Cannot write to ' . $_[0]->pidbase unless -w $_[0]->pidbase;
	48	$_[0]->pidbase . '/' . $_[0]->progname . '.pid';
	49	},
a4952679	50	);
	51
	52	has foreground => (
	53	metaclass => 'Getopt',
	54	cmd_aliases => ['f'],
	55	isa => 'Bool',
	56	is => 'ro',
	57	default => sub { 0 },
	58	);
	59
	60	sub check {
	61	my ($self) = @_;
3543c999	62	if ( my $pid = $self->get_pid ) {
a4952679	63	my $prog = $self->progname;
3543c999	64	if ( CORE::kill 0 => $pid ) {
a392fa53	65	croak "$prog already running ($pid).";
a4952679	66	}
ee08a7fe	67	carp "$prog not running but found pid ($pid)."
ee08a7fe	68	. "Perhaps the pid file (@{ [$self->pidfile] }) is stale?";
a4952679	69	return 1;
	70	}
	71	return 0;
	72	}
	73
a392fa53	74	sub daemonize {
	75	my ($self) = @_;
	76	Proc::Daemon::Init;
	77	}
	78
a4952679	79	sub start {
	80	my ($self) = @_;
	81	return if $self->check;
	82
	83	$self->daemonize unless $self->foreground;
	84
3543c999	85	# Avoid 'stdin reopened for output' warning with newer perls
0585edbb	86	## no critic
3543c999	87	open( NULL, '/dev/null' );
3543c999	88	<NULL> if (0);
0585edbb	89	## use critic
0585edbb	90
24a6a660	91	# Change to basedir
	92	chdir $self->basedir;
	93
3543c999	94	$self->save_pid;
	95	$self->setup_signals;
	96	return $$;
	97	}
	98
	99	sub save_pid {
	100	my ($self) = @_;
a4952679	101	my $pidfile = $self->pidfile;
	102	lock( $pidfile, undef, 'nonblocking' )
	103	or croak "Could not lock PID file $pidfile: $!";
	104	write_file( $pidfile, "$$\n" );
a392fa53	105	unlock($pidfile);
a4952679	106	return;
	107	}
	108
3543c999	109	sub remove_pid {
a4952679	110	my ($self) = @_;
a4952679	111	my $pidfile = $self->pidfile;
a4952679	112	lock( $pidfile, undef, 'nonblocking' )
a4952679	113	or croak "Could not lock PID file $pidfile: $!";
a4952679	114	unlink($pidfile);
a392fa53	115	unlock($pidfile);
a4952679	116	return;
	117	}
	118
3543c999	119	sub get_pid {
	120	my ($self) = @_;
	121	my $pidfile = $self->pidfile;
	122	return unless -e $pidfile;
	123	chomp( my $pid = read_file($pidfile) );
	124	return $pid;
	125	}
	126
	127	sub stop {
	128	my ( $self, %args ) = @_;
	129	my $pid = $self->get_pid;
cecbee2d	130	$self->_kill($pid) unless $self->foreground();
3543c999	131	$self->remove_pid;
	132	return 1 if $args{no_exit};
	133	exit;
	134	}
	135
a4952679	136	sub restart {
a4952679	137	my ($self) = @_;
3543c999	138	$self->stop( noexit => 1 );
a4952679	139	$self->start();
	140	}
	141
a4952679	142	sub setup_signals {
3543c999	143	my ($self) = @_;
	144	$SIG{INT} = sub { $self->handle_sigint; };
	145	$SIG{HUP} = sub { $self->handle_sighup };
a4952679	146	}
a4952679	147
2361a590	148	sub handle_sigint { $_[0]->stop; }
2361a590	149	sub handle_sighup { $_[0]->restart; }
a4952679	150
cecbee2d	151	sub _kill {
cecbee2d	152	confess "_kill isn't public" unless caller eq __PACKAGE__;
a4952679	153	my ( $self, $pid ) = @_;
2361a590	154	return unless $pid;
3543c999	155	unless ( CORE::kill 0 => $pid ) {
	156
	157	# warn "$pid already appears dead.";
	158	return;
	159	}
	160
	161	if ( $pid eq $$ ) {
	162
	163	# warn "$pid is us! Can't commit suicied.";
a4952679	164	return;
	165	}
	166
3543c999	167	CORE::kill( 2, $pid ); # Try SIGINT
2361a590	168	sleep(2) if CORE::kill( 0, $pid );
a4952679	169
3543c999	170	unless ( CORE::kill 0 => $pid or $!{EPERM} ) { # IF it is still running
3543c999	171	CORE::kill( 15, $pid ); # try SIGTERM
2361a590	172	sleep(2) if CORE::kill( 0, $pid );
a4952679	173	}
a4952679	174
3543c999	175	unless ( CORE::kill 0 => $pid or $!{EPERM} ) { # IF it is still running
3543c999	176	CORE::kill( 9, $pid ); # finally try SIGKILL
2361a590	177	sleep(2) if CORE::kill( 0, $pid );
a4952679	178	}
a4952679	179
3543c999	180	unless ( CORE::kill 0 => $pid or $!{EPERM} ) { # IF it is still running
3543c999	181	carp "$pid doesn't seem to want to die."; # AHH EVIL DEAD!
a4952679	182	}
	183
	184	return;
	185	}
	186
	187	1;
	188	__END__
	189
a4952679	190	=head1 NAME
	191
	192	MooseX::Daemonize - provides a Role that daemonizes your Moose based application.
	193
	194
	195	=head1 VERSION
	196
	197	This document describes MooseX::Daemonize version 0.0.1
	198
	199
	200	=head1 SYNOPSIS
	201
	202	package FileMaker;
	203	use Moose;
	204	with qw(MooseX::Daemonize);
	205
	206	sub create_file {
	207	my ( $self, $file ) = @_;
	208	open( FILE, ">$file" ) \|\| die;
	209	close(FILE);
	210	}
	211
	212	no Moose;
	213
	214	# then in the main package ...
	215
	216	my $daemon = FileMaker->new();
	217	$daemon->start();
	218	$daemon->create_file($file);
	219	$daemon->stop();
	220
	221	=head1 DESCRIPTION
	222
	223	Often you want to write a persistant daemon that has a pid file, and responds appropriately to Signals.
	224	This module helps provide the basic infrastructure to do that.
	225
	226	=head1 ATTRIBUTES
	227
	228	=over
	229
	230	=item progname Str
	231
	232	The name of our daemon, defaults to $0
	233
	234	=item pidbase Str
	235
	236	The base for our bid, defaults to /var/run/$progname
	237
	238	=item pidfile Str
	239
	240	The file we store our PID in, defaults to /var/run/$progname/
	241
	242	=item foreground Bool
	243
	244	If true, the process won't background. Useful for debugging. This option can be set via Getopt's -f.
	245
	246	=back
	247
	248	=head1 METHODS
	249
	250	=over
	251
	252	=item check()
	253
254	Check to see if an instance is already running.
255
256	=item start()
257
258	Setup a pidfile, fork, then setup the signal handlers.
259
260	=item stop()
261
262	Stop the process matching the pidfile, and unlinks the pidfile.
263
264	=item restart()
265
266	Litterally
267
268	$self->stop();
269	$self->start();
270
271	=item daemonize()
272
273	Calls C<Proc::Daemon::Init> to daemonize this process.
274
275	=item kill($pid)
276
277	Kills the process for $pid. This will try SIGINT, and SIGTERM before falling back to SIGKILL and finally giving up.
278
279	=item setup_signals()
280
281	Setup the signal handlers, by default it only sets up handlers for SIGINT and SIGHUP
282
283	=item handle_sigint()
284
cecbee2d	285	Handle a INT signal, by default calls C<$self->stop()>
a4952679	286
	287	=item handle_sighup()
	288
cecbee2d	289	Handle a HUP signal. By default calls C<$self->restart()>
a4952679	290
3543c999	291	=item get_pid
3543c999	292
cecbee2d	293	Lookup the pid from our pidfile.
cecbee2d	294
3543c999	295	=item save_pid
3543c999	296
cecbee2d	297	Save the current pid in our pidfile
cecbee2d	298
3543c999	299	=item remove_pid
3543c999	300
cecbee2d	301	Delete our pidfile
cecbee2d	302
a4952679	303	=item meta()
a4952679	304
cecbee2d	305	The C<meta()> method from L<Class::MOP::Class>
a4952679	306
	307	=back
	308
	309	=head1 DEPENDENCIES
	310
	311	=for author to fill in:
	312	A list of all the other modules that this module relies upon,
	313	including any restrictions on versions, and an indication whether
	314	the module is part of the standard Perl distribution, part of the
	315	module's distribution, or must be installed separately. ]
	316
	317	Obviously L<Moose>, also L<Carp>, L<Proc::Daemon>, L<File::Flock>, L<File::Slurp>
	318
	319	=head1 INCOMPATIBILITIES
	320
	321	=for author to fill in:
	322	A list of any modules that this module cannot be used in conjunction
	323	with. This may be due to name conflicts in the interface, or
	324	competition for system or program resources, or due to internal
	325	limitations of Perl (for example, many modules that use source code
	326	filters are mutually incompatible).
	327
	328	None reported.
	329
	330
	331	=head1 BUGS AND LIMITATIONS
	332
	333	=for author to fill in:
	334	A list of known problems with the module, together with some
	335	indication Whether they are likely to be fixed in an upcoming
	336	release. Also a list of restrictions on the features the module
	337	does provide: data types that cannot be handled, performance issues
	338	and the circumstances in which they may arise, practical
	339	limitations on the size of data sets, special cases that are not
	340	(yet) handled, etc.
	341
	342	No bugs have been reported.
	343
	344	Please report any bugs or feature requests to
	345	C<bug-acme-dahut-call@rt.cpan.org>, or through the web interface at
	346	L<http://rt.cpan.org>.
	347
	348	=head1 SEE ALSO
	349
	350	L<Proc::Daemon>, L<Daemon::Generic>, L<MooseX::Getopt>
	351
	352	=head1 AUTHOR
	353
	354	Chris Prather C<< <perigrin@cpan.org> >>
	355
	356
	357	=head1 LICENCE AND COPYRIGHT
	358
	359	Copyright (c) 2007, Chris Prather C<< <perigrin@cpan.org> >>. All rights reserved.
	360
	361	This module is free software; you can redistribute it and/or
	362	modify it under the same terms as Perl itself. See L<perlartistic>.
	363
	364
	365	=head1 DISCLAIMER OF WARRANTY
	366
	367	BECAUSE THIS SOFTWARE IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY
	368	FOR THE SOFTWARE, TO THE EXTENT PERMITTED BY APPLICABLE LAW. EXCEPT WHEN
	369	OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES
370	PROVIDE THE SOFTWARE "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER
371	EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
372	WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE
373	ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE SOFTWARE IS WITH
374	YOU. SHOULD THE SOFTWARE PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL
375	NECESSARY SERVICING, REPAIR, OR CORRECTION.
376
377	IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
378	WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR
379	REDISTRIBUTE THE SOFTWARE AS PERMITTED BY THE ABOVE LICENCE, BE
380	LIABLE TO YOU FOR DAMAGES, INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL,
381	OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE
382	THE SOFTWARE (INCLUDING BUT NOT LIMITED TO LOSS OF DATA OR DATA BEING
383	RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD PARTIES OR A
384	FAILURE OF THE SOFTWARE TO OPERATE WITH ANY OTHER SOFTWARE), EVEN IF
385	SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF
386	SUCH DAMAGES.