[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 $pid exists. Perhaps it 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
    open( NULL, '/dev/null' );
    <NULL> if (0);

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