[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 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
    
    $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 {
    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. Nothing is done by default.

=item get_pid

=item save_pid

=item remove_pid

=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	);
	24
	25	has pidbase => (
2361a590	26	isa => 'Str',
	27	is => 'ro',
	28
	29	# required => 1,
	30	lazy => 1,
	31	default => sub { return '/var/run' },
a4952679	32	);
	33
	34	has pidfile => (
	35	isa => 'Str',
	36	is => 'ro',
	37	lazy => 1,
	38	required => 1,
3543c999	39	default => sub {
	40	die 'Cannot write to ' . $_[0]->pidbase unless -w $_[0]->pidbase;
	41	$_[0]->pidbase . '/' . $_[0]->progname . '.pid';
	42	},
a4952679	43	);
	44
	45	has foreground => (
	46	metaclass => 'Getopt',
	47	cmd_aliases => ['f'],
	48	isa => 'Bool',
	49	is => 'ro',
	50	default => sub { 0 },
	51	);
	52
	53	sub check {
	54	my ($self) = @_;
3543c999	55	if ( my $pid = $self->get_pid ) {
a4952679	56	my $prog = $self->progname;
3543c999	57	if ( CORE::kill 0 => $pid ) {
a392fa53	58	croak "$prog already running ($pid).";
a4952679	59	}
ee08a7fe	60	carp "$prog not running but found pid ($pid)."
ee08a7fe	61	. "Perhaps the pid file (@{ [$self->pidfile] }) is stale?";
a4952679	62	return 1;
	63	}
	64	return 0;
	65	}
	66
a392fa53	67	sub daemonize {
	68	my ($self) = @_;
	69	Proc::Daemon::Init;
	70	}
	71
a4952679	72	sub start {
	73	my ($self) = @_;
	74	return if $self->check;
	75
	76	$self->daemonize unless $self->foreground;
	77
3543c999	78	# Avoid 'stdin reopened for output' warning with newer perls
0585edbb	79	## no critic
3543c999	80	open( NULL, '/dev/null' );
3543c999	81	<NULL> if (0);
0585edbb	82	## use critic
0585edbb	83
3543c999	84	$self->save_pid;
	85	$self->setup_signals;
	86	return $$;
	87	}
	88
	89	sub save_pid {
	90	my ($self) = @_;
a4952679	91	my $pidfile = $self->pidfile;
	92	lock( $pidfile, undef, 'nonblocking' )
	93	or croak "Could not lock PID file $pidfile: $!";
	94	write_file( $pidfile, "$$\n" );
a392fa53	95	unlock($pidfile);
a4952679	96	return;
	97	}
	98
3543c999	99	sub remove_pid {
a4952679	100	my ($self) = @_;
a4952679	101	my $pidfile = $self->pidfile;
a4952679	102	lock( $pidfile, undef, 'nonblocking' )
a4952679	103	or croak "Could not lock PID file $pidfile: $!";
a4952679	104	unlink($pidfile);
a392fa53	105	unlock($pidfile);
a4952679	106	return;
	107	}
	108
3543c999	109	sub get_pid {
	110	my ($self) = @_;
	111	my $pidfile = $self->pidfile;
	112	return unless -e $pidfile;
	113	chomp( my $pid = read_file($pidfile) );
	114	return $pid;
	115	}
	116
	117	sub stop {
	118	my ( $self, %args ) = @_;
	119	my $pid = $self->get_pid;
	120	$self->kill($pid) unless $self->foreground();
	121	$self->remove_pid;
	122	return 1 if $args{no_exit};
	123	exit;
	124	}
	125
a4952679	126	sub restart {
a4952679	127	my ($self) = @_;
3543c999	128	$self->stop( noexit => 1 );
a4952679	129	$self->start();
	130	}
	131
a4952679	132	sub setup_signals {
3543c999	133	my ($self) = @_;
	134	$SIG{INT} = sub { $self->handle_sigint; };
	135	$SIG{HUP} = sub { $self->handle_sighup };
a4952679	136	}
a4952679	137
2361a590	138	sub handle_sigint { $_[0]->stop; }
2361a590	139	sub handle_sighup { $_[0]->restart; }
a4952679	140
	141	sub kill {
	142	my ( $self, $pid ) = @_;
2361a590	143	return unless $pid;
3543c999	144	unless ( CORE::kill 0 => $pid ) {
	145
	146	# warn "$pid already appears dead.";
	147	return;
	148	}
	149
	150	if ( $pid eq $$ ) {
	151
	152	# warn "$pid is us! Can't commit suicied.";
a4952679	153	return;
	154	}
	155
3543c999	156	CORE::kill( 2, $pid ); # Try SIGINT
2361a590	157	sleep(2) if CORE::kill( 0, $pid );
a4952679	158
3543c999	159	unless ( CORE::kill 0 => $pid or $!{EPERM} ) { # IF it is still running
3543c999	160	CORE::kill( 15, $pid ); # try SIGTERM
2361a590	161	sleep(2) if CORE::kill( 0, $pid );
a4952679	162	}
a4952679	163
3543c999	164	unless ( CORE::kill 0 => $pid or $!{EPERM} ) { # IF it is still running
3543c999	165	CORE::kill( 9, $pid ); # finally try SIGKILL
2361a590	166	sleep(2) if CORE::kill( 0, $pid );
a4952679	167	}
a4952679	168
3543c999	169	unless ( CORE::kill 0 => $pid or $!{EPERM} ) { # IF it is still running
3543c999	170	carp "$pid doesn't seem to want to die."; # AHH EVIL DEAD!
a4952679	171	}
	172
	173	return;
	174	}
	175
	176	1;
	177	__END__
	178
a4952679	179	=head1 NAME
	180
	181	MooseX::Daemonize - provides a Role that daemonizes your Moose based application.
	182
	183
	184	=head1 VERSION
	185
	186	This document describes MooseX::Daemonize version 0.0.1
	187
	188
	189	=head1 SYNOPSIS
	190
	191	package FileMaker;
	192	use Moose;
	193	with qw(MooseX::Daemonize);
	194
	195	sub create_file {
	196	my ( $self, $file ) = @_;
	197	open( FILE, ">$file" ) \|\| die;
	198	close(FILE);
	199	}
	200
	201	no Moose;
	202
	203	# then in the main package ...
	204
	205	my $daemon = FileMaker->new();
	206	$daemon->start();
	207	$daemon->create_file($file);
	208	$daemon->stop();
	209
	210	=head1 DESCRIPTION
	211
	212	Often you want to write a persistant daemon that has a pid file, and responds appropriately to Signals.
	213	This module helps provide the basic infrastructure to do that.
	214
	215	=head1 ATTRIBUTES
	216
	217	=over
	218
	219	=item progname Str
	220
	221	The name of our daemon, defaults to $0
	222
	223	=item pidbase Str
	224
	225	The base for our bid, defaults to /var/run/$progname
	226
	227	=item pidfile Str
	228
	229	The file we store our PID in, defaults to /var/run/$progname/
	230
	231	=item foreground Bool
	232
	233	If true, the process won't background. Useful for debugging. This option can be set via Getopt's -f.
	234
	235	=back
	236
	237	=head1 METHODS
	238
	239	=over
	240
	241	=item check()
	242
243	Check to see if an instance is already running.
244
245	=item start()
246
247	Setup a pidfile, fork, then setup the signal handlers.
248
249	=item stop()
250
251	Stop the process matching the pidfile, and unlinks the pidfile.
252
253	=item restart()
254
255	Litterally
256
257	$self->stop();
258	$self->start();
259
260	=item daemonize()
261
262	Calls C<Proc::Daemon::Init> to daemonize this process.
263
264	=item kill($pid)
265
266	Kills the process for $pid. This will try SIGINT, and SIGTERM before falling back to SIGKILL and finally giving up.
267
268	=item setup_signals()
269
270	Setup the signal handlers, by default it only sets up handlers for SIGINT and SIGHUP
271
272	=item handle_sigint()
273
274	Handle a INT signal, by default calls C<$self->stop()>;
275
276	=item handle_sighup()
277
278	Handle a HUP signal. Nothing is done by default.
279
3543c999	280	=item get_pid
	281
	282	=item save_pid
	283
	284	=item remove_pid
	285
a4952679	286	=item meta()
	287
	288	the C<meta()> method from L<Class::MOP::Class>
	289
	290	=back
	291
	292	=head1 DEPENDENCIES
	293
	294	=for author to fill in:
	295	A list of all the other modules that this module relies upon,
	296	including any restrictions on versions, and an indication whether
	297	the module is part of the standard Perl distribution, part of the
	298	module's distribution, or must be installed separately. ]
	299
	300	Obviously L<Moose>, also L<Carp>, L<Proc::Daemon>, L<File::Flock>, L<File::Slurp>
	301
	302	=head1 INCOMPATIBILITIES
	303
	304	=for author to fill in:
	305	A list of any modules that this module cannot be used in conjunction
	306	with. This may be due to name conflicts in the interface, or
	307	competition for system or program resources, or due to internal
	308	limitations of Perl (for example, many modules that use source code
	309	filters are mutually incompatible).
	310
	311	None reported.
	312
	313
	314	=head1 BUGS AND LIMITATIONS
	315
	316	=for author to fill in:
	317	A list of known problems with the module, together with some
	318	indication Whether they are likely to be fixed in an upcoming
	319	release. Also a list of restrictions on the features the module
	320	does provide: data types that cannot be handled, performance issues
	321	and the circumstances in which they may arise, practical
	322	limitations on the size of data sets, special cases that are not
	323	(yet) handled, etc.
	324
	325	No bugs have been reported.
	326
	327	Please report any bugs or feature requests to
	328	C<bug-acme-dahut-call@rt.cpan.org>, or through the web interface at
	329	L<http://rt.cpan.org>.
	330
	331	=head1 SEE ALSO
	332
	333	L<Proc::Daemon>, L<Daemon::Generic>, L<MooseX::Getopt>
	334
	335	=head1 AUTHOR
	336
	337	Chris Prather C<< <perigrin@cpan.org> >>
	338
	339
	340	=head1 LICENCE AND COPYRIGHT
	341
	342	Copyright (c) 2007, Chris Prather C<< <perigrin@cpan.org> >>. All rights reserved.
	343
	344	This module is free software; you can redistribute it and/or
	345	modify it under the same terms as Perl itself. See L<perlartistic>.
	346
	347
	348	=head1 DISCLAIMER OF WARRANTY
	349
350	BECAUSE THIS SOFTWARE IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY
351	FOR THE SOFTWARE, TO THE EXTENT PERMITTED BY APPLICABLE LAW. EXCEPT WHEN
352	OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES
353	PROVIDE THE SOFTWARE "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER
354	EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
355	WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE
356	ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE SOFTWARE IS WITH
357	YOU. SHOULD THE SOFTWARE PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL
358	NECESSARY SERVICING, REPAIR, OR CORRECTION.
359
360	IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
361	WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR
362	REDISTRIBUTE THE SOFTWARE AS PERMITTED BY THE ABOVE LICENCE, BE
363	LIABLE TO YOU FOR DAMAGES, INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL,
364	OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE
365	THE SOFTWARE (INCLUDING BUT NOT LIMITED TO LOSS OF DATA OR DATA BEING
366	RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD PARTIES OR A
367	FAILURE OF THE SOFTWARE TO OPERATE WITH ANY OTHER SOFTWARE), EVEN IF
368	SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF
369	SUCH DAMAGES.