[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 {
    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	);
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;
	130	$self->kill($pid) unless $self->foreground();
	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
	151	sub kill {
	152	my ( $self, $pid ) = @_;
2361a590	153	return unless $pid;
3543c999	154	unless ( CORE::kill 0 => $pid ) {
	155
	156	# warn "$pid already appears dead.";
	157	return;
	158	}
	159
	160	if ( $pid eq $$ ) {
	161
	162	# warn "$pid is us! Can't commit suicied.";
a4952679	163	return;
	164	}
	165
3543c999	166	CORE::kill( 2, $pid ); # Try SIGINT
2361a590	167	sleep(2) if CORE::kill( 0, $pid );
a4952679	168
3543c999	169	unless ( CORE::kill 0 => $pid or $!{EPERM} ) { # IF it is still running
3543c999	170	CORE::kill( 15, $pid ); # try SIGTERM
2361a590	171	sleep(2) if CORE::kill( 0, $pid );
a4952679	172	}
a4952679	173
3543c999	174	unless ( CORE::kill 0 => $pid or $!{EPERM} ) { # IF it is still running
3543c999	175	CORE::kill( 9, $pid ); # finally try SIGKILL
2361a590	176	sleep(2) if CORE::kill( 0, $pid );
a4952679	177	}
a4952679	178
3543c999	179	unless ( CORE::kill 0 => $pid or $!{EPERM} ) { # IF it is still running
3543c999	180	carp "$pid doesn't seem to want to die."; # AHH EVIL DEAD!
a4952679	181	}
	182
	183	return;
	184	}
	185
	186	1;
	187	__END__
	188
a4952679	189	=head1 NAME
	190
	191	MooseX::Daemonize - provides a Role that daemonizes your Moose based application.
	192
	193
	194	=head1 VERSION
	195
	196	This document describes MooseX::Daemonize version 0.0.1
	197
	198
	199	=head1 SYNOPSIS
	200
	201	package FileMaker;
	202	use Moose;
	203	with qw(MooseX::Daemonize);
	204
	205	sub create_file {
	206	my ( $self, $file ) = @_;
	207	open( FILE, ">$file" ) \|\| die;
	208	close(FILE);
	209	}
	210
	211	no Moose;
	212
	213	# then in the main package ...
	214
	215	my $daemon = FileMaker->new();
	216	$daemon->start();
	217	$daemon->create_file($file);
	218	$daemon->stop();
	219
	220	=head1 DESCRIPTION
	221
	222	Often you want to write a persistant daemon that has a pid file, and responds appropriately to Signals.
	223	This module helps provide the basic infrastructure to do that.
	224
	225	=head1 ATTRIBUTES
	226
	227	=over
	228
	229	=item progname Str
	230
	231	The name of our daemon, defaults to $0
	232
	233	=item pidbase Str
	234
	235	The base for our bid, defaults to /var/run/$progname
	236
	237	=item pidfile Str
	238
	239	The file we store our PID in, defaults to /var/run/$progname/
	240
	241	=item foreground Bool
	242
	243	If true, the process won't background. Useful for debugging. This option can be set via Getopt's -f.
	244
	245	=back
	246
	247	=head1 METHODS
	248
	249	=over
	250
	251	=item check()
	252
253	Check to see if an instance is already running.
254
255	=item start()
256
257	Setup a pidfile, fork, then setup the signal handlers.
258
259	=item stop()
260
261	Stop the process matching the pidfile, and unlinks the pidfile.
262
263	=item restart()
264
265	Litterally
266
267	$self->stop();
268	$self->start();
269
270	=item daemonize()
271
272	Calls C<Proc::Daemon::Init> to daemonize this process.
273
274	=item kill($pid)
275
276	Kills the process for $pid. This will try SIGINT, and SIGTERM before falling back to SIGKILL and finally giving up.
277
278	=item setup_signals()
279
280	Setup the signal handlers, by default it only sets up handlers for SIGINT and SIGHUP
281
282	=item handle_sigint()
283
284	Handle a INT signal, by default calls C<$self->stop()>;
285
286	=item handle_sighup()
287
288	Handle a HUP signal. Nothing is done by default.
289
3543c999	290	=item get_pid
	291
	292	=item save_pid
	293
	294	=item remove_pid
	295
a4952679	296	=item meta()
	297
	298	the C<meta()> method from L<Class::MOP::Class>
	299
	300	=back
	301
	302	=head1 DEPENDENCIES
	303
	304	=for author to fill in:
	305	A list of all the other modules that this module relies upon,
	306	including any restrictions on versions, and an indication whether
	307	the module is part of the standard Perl distribution, part of the
	308	module's distribution, or must be installed separately. ]
	309
	310	Obviously L<Moose>, also L<Carp>, L<Proc::Daemon>, L<File::Flock>, L<File::Slurp>
	311
	312	=head1 INCOMPATIBILITIES
	313
	314	=for author to fill in:
	315	A list of any modules that this module cannot be used in conjunction
	316	with. This may be due to name conflicts in the interface, or
	317	competition for system or program resources, or due to internal
	318	limitations of Perl (for example, many modules that use source code
	319	filters are mutually incompatible).
	320
	321	None reported.
	322
	323
	324	=head1 BUGS AND LIMITATIONS
	325
	326	=for author to fill in:
	327	A list of known problems with the module, together with some
	328	indication Whether they are likely to be fixed in an upcoming
	329	release. Also a list of restrictions on the features the module
	330	does provide: data types that cannot be handled, performance issues
	331	and the circumstances in which they may arise, practical
	332	limitations on the size of data sets, special cases that are not
	333	(yet) handled, etc.
	334
	335	No bugs have been reported.
	336
	337	Please report any bugs or feature requests to
	338	C<bug-acme-dahut-call@rt.cpan.org>, or through the web interface at
	339	L<http://rt.cpan.org>.
	340
	341	=head1 SEE ALSO
	342
	343	L<Proc::Daemon>, L<Daemon::Generic>, L<MooseX::Getopt>
	344
	345	=head1 AUTHOR
	346
	347	Chris Prather C<< <perigrin@cpan.org> >>
	348
	349
	350	=head1 LICENCE AND COPYRIGHT
	351
	352	Copyright (c) 2007, Chris Prather C<< <perigrin@cpan.org> >>. All rights reserved.
	353
	354	This module is free software; you can redistribute it and/or
	355	modify it under the same terms as Perl itself. See L<perlartistic>.
	356
	357
	358	=head1 DISCLAIMER OF WARRANTY
	359
360	BECAUSE THIS SOFTWARE IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY
361	FOR THE SOFTWARE, TO THE EXTENT PERMITTED BY APPLICABLE LAW. EXCEPT WHEN
362	OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES
363	PROVIDE THE SOFTWARE "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER
364	EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
365	WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE
366	ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE SOFTWARE IS WITH
367	YOU. SHOULD THE SOFTWARE PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL
368	NECESSARY SERVICING, REPAIR, OR CORRECTION.
369
370	IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
371	WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR
372	REDISTRIBUTE THE SOFTWARE AS PERMITTED BY THE ABOVE LICENCE, BE
373	LIABLE TO YOU FOR DAMAGES, INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL,
374	OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE
375	THE SOFTWARE (INCLUDING BUT NOT LIMITED TO LOSS OF DATA OR DATA BEING
376	RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD PARTIES OR A
377	FAILURE OF THE SOFTWARE TO OPERATE WITH ANY OTHER SOFTWARE), EVEN IF
378	SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF
379	SUCH DAMAGES.