[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',
    default => sub { lc $_[0]->meta->name },
);

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

has pidfile => (
    isa      => 'Str',
    is       => 'ro',
    lazy     => 1,
    required => 1,
    default  => sub { $_[0]->pidbase .'/'. $_[0]->progname . '.pid' },
);

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

sub check {
    my ($self) = @_;
    my $pidfile = $self->pidfile;
    if ( -e $pidfile ) {
        my $prog = $self->progname;
        chomp( my $pid = read_file($pidfile) );
        unless ( kill 0 => $pid or $!{EPERM} ) {
            carp "$prog already running ($pid).";
        }
        else {
            carp "$prog not running but $pidfile exists. Perhaps it is stale?";
        }
        return 1;
    }
    return 0;
}

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

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

    my $pidfile = $self->pidfile;
    lock( $pidfile, undef, 'nonblocking' )
      or croak "Could not lock PID file $pidfile: $!";
    write_file( $pidfile, "$$\n" );

    $self->setup_signals;
    return;
}

sub stop {
    my ($self) = @_;
    my $pidfile = $self->pidfile;
    unless ( -e $pidfile ) {
        croak $self->progname . 'is not currently running.';
    }
    lock( $pidfile, undef, 'nonblocking' )
      or croak "Could not lock PID file $pidfile: $!";
    chomp( my $pid = read_file($pidfile) );
    $self->kill($pid);
    unlink($pidfile);
    return;
}

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

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

sub setup_signals {
    my $self = @_;
    $SIG{INT} = sub { $_[0]->handle_sigint; };
    $SIG{HUP} = sub { $_[0]->handle_sighup };
}

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

sub kill {
    my ( $self, $pid ) = @_;
    unless ( kill 0 => $pid or $!{EPERM} ) {
        carp "$pid appears dead.";
        return;
    }

    kill( 2, $pid );    # Try SIGINT
    sleep(1) if kill( 0, $pid );

    unless ( kill 0 => $pid or $!{EPERM} ) {    # IF it is still running
        kill( 15, $pid );                       # try SIGTERM
        sleep(1) if kill( 0, $pid );
    }

    unless ( kill 0 => $pid or $!{EPERM} ) {    # IF it is still running
        kill( 9, $pid );                        # finally try SIGKILL
        sleep(1) if kill( 0, $pid );
    }

    unless ( 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 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;
	2	use strict; # because Kwalitee is pedantic
	3	use Moose::Role;
	4
	5	our $VERSION = 0.01;
	6	use Carp;
	7	use Proc::Daemon;
	8	use File::Flock;
	9	use File::Slurp;
	10
	11	with qw(MooseX::Getopt);
	12
	13	has progname => (
	14	isa => 'Str',
	15	is => 'ro',
	16	default => sub { lc $_[0]->meta->name },
	17	);
	18
	19	has pidbase => (
	20	isa => 'Str',
	21	is => 'ro',
	22	lazy => 1,
	23	required => 1,
	24	default => sub { return '/var/run' },
	25	);
	26
	27	has pidfile => (
	28	isa => 'Str',
	29	is => 'ro',
	30	lazy => 1,
	31	required => 1,
	32	default => sub { $_[0]->pidbase .'/'. $_[0]->progname . '.pid' },
	33	);
	34
	35	has foreground => (
	36	metaclass => 'Getopt',
	37	cmd_aliases => ['f'],
	38	isa => 'Bool',
	39	is => 'ro',
	40	default => sub { 0 },
	41	);
	42
	43	sub check {
	44	my ($self) = @_;
	45	my $pidfile = $self->pidfile;
	46	if ( -e $pidfile ) {
	47	my $prog = $self->progname;
	48	chomp( my $pid = read_file($pidfile) );
	49	unless ( kill 0 => $pid or $!{EPERM} ) {
	50	carp "$prog already running ($pid).";
	51	}
	52	else {
	53	carp "$prog not running but $pidfile exists. Perhaps it is stale?";
	54	}
	55	return 1;
	56	}
	57	return 0;
	58	}
	59
	60	sub start {
	61	my ($self) = @_;
	62	return if $self->check;
	63
	64	$self->daemonize unless $self->foreground;
65
66	my $pidfile = $self->pidfile;
67	lock( $pidfile, undef, 'nonblocking' )
68	or croak "Could not lock PID file $pidfile: $!";
69	write_file( $pidfile, "$$\n" );
70
71	$self->setup_signals;
72	return;
73	}
74
75	sub stop {
76	my ($self) = @_;
77	my $pidfile = $self->pidfile;
78	unless ( -e $pidfile ) {
79	croak $self->progname . 'is not currently running.';
80	}
81	lock( $pidfile, undef, 'nonblocking' )
82	or croak "Could not lock PID file $pidfile: $!";
83	chomp( my $pid = read_file($pidfile) );
84	$self->kill($pid);
85	unlink($pidfile);
86	return;
87	}
88
89	sub restart {
90	my ($self) = @_;
91	$self->stop();
92	$self->start();
93	}
94
95	sub daemonize {
96	my ($self) = @_;
97	Proc::Daemon::Init;
98	}
99
100	sub setup_signals {
101	my $self = @_;
102	$SIG{INT} = sub { $_[0]->handle_sigint; };
103	$SIG{HUP} = sub { $_[0]->handle_sighup };
104	}
105
106	sub handle_sigint { $_[0]->stop; }
107	sub handle_sighup { return; }
108
109	sub kill {
110	my ( $self, $pid ) = @_;
111	unless ( kill 0 => $pid or $!{EPERM} ) {
112	carp "$pid appears dead.";
113	return;
114	}
115
116	kill( 2, $pid ); # Try SIGINT
117	sleep(1) if kill( 0, $pid );
118
119	unless ( kill 0 => $pid or $!{EPERM} ) { # IF it is still running
120	kill( 15, $pid ); # try SIGTERM
121	sleep(1) if kill( 0, $pid );
122	}
123
124	unless ( kill 0 => $pid or $!{EPERM} ) { # IF it is still running
125	kill( 9, $pid ); # finally try SIGKILL
126	sleep(1) if kill( 0, $pid );
127	}
128
129	unless ( kill 0 => $pid or $!{EPERM} ) { # IF it is still running
130	carp "$pid doesn't seem to want to die."; # AHH EVIL DEAD!
131	}
132
133	return;
134	}
135
136	1;
137	__END__
138
a4952679	139	=head1 NAME
	140
	141	MooseX::Daemonize - provides a Role that daemonizes your Moose based application.
	142
	143
	144	=head1 VERSION
	145
	146	This document describes MooseX::Daemonize version 0.0.1
	147
	148
	149	=head1 SYNOPSIS
	150
	151	package FileMaker;
	152	use Moose;
	153	with qw(MooseX::Daemonize);
	154
	155	sub create_file {
	156	my ( $self, $file ) = @_;
	157	open( FILE, ">$file" ) \|\| die;
	158	close(FILE);
	159	}
	160
	161	no Moose;
	162
	163	# then in the main package ...
	164
	165	my $daemon = FileMaker->new();
	166	$daemon->start();
	167	$daemon->create_file($file);
	168	$daemon->stop();
	169
	170	=head1 DESCRIPTION
	171
	172	Often you want to write a persistant daemon that has a pid file, and responds appropriately to Signals.
	173	This module helps provide the basic infrastructure to do that.
	174
	175	=head1 ATTRIBUTES
	176
	177	=over
	178
	179	=item progname Str
	180
	181	The name of our daemon, defaults to $0
	182
	183	=item pidbase Str
	184
	185	The base for our bid, defaults to /var/run/$progname
	186
	187	=item pidfile Str
	188
	189	The file we store our PID in, defaults to /var/run/$progname/
	190
	191	=item foreground Bool
	192
	193	If true, the process won't background. Useful for debugging. This option can be set via Getopt's -f.
	194
	195	=back
	196
	197	=head1 METHODS
	198
	199	=over
	200
	201	=item check()
	202
203	Check to see if an instance is already running.
204
205	=item start()
206
207	Setup a pidfile, fork, then setup the signal handlers.
208
209	=item stop()
210
211	Stop the process matching the pidfile, and unlinks the pidfile.
212
213	=item restart()
214
215	Litterally
216
217	$self->stop();
218	$self->start();
219
220	=item daemonize()
221
222	Calls C<Proc::Daemon::Init> to daemonize this process.
223
224	=item kill($pid)
225
226	Kills the process for $pid. This will try SIGINT, and SIGTERM before falling back to SIGKILL and finally giving up.
227
228	=item setup_signals()
229
230	Setup the signal handlers, by default it only sets up handlers for SIGINT and SIGHUP
231
232	=item handle_sigint()
233
234	Handle a INT signal, by default calls C<$self->stop()>;
235
236	=item handle_sighup()
237
238	Handle a HUP signal. Nothing is done by default.
239
240	=item meta()
241
242	the C<meta()> method from L<Class::MOP::Class>
243
244	=back
245
246	=head1 DEPENDENCIES
247
248	=for author to fill in:
249	A list of all the other modules that this module relies upon,
250	including any restrictions on versions, and an indication whether
251	the module is part of the standard Perl distribution, part of the
252	module's distribution, or must be installed separately. ]
253
254	Obviously L<Moose>, also L<Carp>, L<Proc::Daemon>, L<File::Flock>, L<File::Slurp>
255
256	=head1 INCOMPATIBILITIES
257
258	=for author to fill in:
259	A list of any modules that this module cannot be used in conjunction
260	with. This may be due to name conflicts in the interface, or
261	competition for system or program resources, or due to internal
262	limitations of Perl (for example, many modules that use source code
263	filters are mutually incompatible).
264
265	None reported.
266
267
268	=head1 BUGS AND LIMITATIONS
269
270	=for author to fill in:
271	A list of known problems with the module, together with some
272	indication Whether they are likely to be fixed in an upcoming
273	release. Also a list of restrictions on the features the module
274	does provide: data types that cannot be handled, performance issues
275	and the circumstances in which they may arise, practical
276	limitations on the size of data sets, special cases that are not
277	(yet) handled, etc.
278
279	No bugs have been reported.
280
281	Please report any bugs or feature requests to
282	C<bug-acme-dahut-call@rt.cpan.org>, or through the web interface at
283	L<http://rt.cpan.org>.
284
285	=head1 SEE ALSO
286
287	L<Proc::Daemon>, L<Daemon::Generic>, L<MooseX::Getopt>
288
289	=head1 AUTHOR
290
291	Chris Prather C<< <perigrin@cpan.org> >>
292
293
294	=head1 LICENCE AND COPYRIGHT
295
296	Copyright (c) 2007, Chris Prather C<< <perigrin@cpan.org> >>. All rights reserved.
297
298	This module is free software; you can redistribute it and/or
299	modify it under the same terms as Perl itself. See L<perlartistic>.
300
301
302	=head1 DISCLAIMER OF WARRANTY
303
304	BECAUSE THIS SOFTWARE IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY
305	FOR THE SOFTWARE, TO THE EXTENT PERMITTED BY APPLICABLE LAW. EXCEPT WHEN
306	OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES
307	PROVIDE THE SOFTWARE "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER
308	EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
309	WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE
310	ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE SOFTWARE IS WITH
311	YOU. SHOULD THE SOFTWARE PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL
312	NECESSARY SERVICING, REPAIR, OR CORRECTION.
313
314	IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
315	WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR
316	REDISTRIBUTE THE SOFTWARE AS PERMITTED BY THE ABOVE LICENCE, BE
317	LIABLE TO YOU FOR DAMAGES, INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL,
318	OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE
319	THE SOFTWARE (INCLUDING BUT NOT LIMITED TO LOSS OF DATA OR DATA BEING
320	RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD PARTIES OR A
321	FAILURE OF THE SOFTWARE TO OPERATE WITH ANY OTHER SOFTWARE), EVEN IF
322	SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF
323	SUCH DAMAGES.