#! /usr/bin/perl

use strict;
use warnings;

use Getopt::Long;
use Pod::Usage;
use Server::Starter qw(start_server restart_server);

my %opts = (
    port => [],
    path => [],
);

GetOptions(
    map {
        $_ => do {
            my $name = (split '=', $_, 2)[0];
            $name =~ s/-/_/g;
            $opts{$name} ||= undef;
            ref($opts{$name}) ? $opts{$name} : \$opts{$name};
        },
    } qw(port=s path=s interval=i log-file=s pid-file=s dir=s signal-on-hup=s signal-on-term=s
         backlog=i envdir=s enable-auto-restart=i auto-restart-interval=i kill-old-delay=i
         status-file=s restart help version),
) or exit 1;
pod2usage(
    -exitval => 0,
    -verbose => 1,
) if $opts{help};
if ($opts{version}) {
    print "$Server::Starter::VERSION\n";
    exit 0;
}

if ($opts{restart}) {
    restart_server(%opts);
    exit 0;
}

# validate options
die "server program not specified\n"
    unless @ARGV;

start_server(
    %opts,
    exec => \@ARGV,
);

__END__

=head1 NAME

start_server - a superdaemon for hot-deploying server programs

=head1 SYNOPSIS

  start_server [options] -- server-prog server-arg1 server-arg2 ...

  # start Plack using Starlet listening at TCP port 8000
  start_server --port=8000 -- plackup -s Starlet --max-workers=100 index.psgi

=head1 DESCRIPTION

This script is a frontend of L<Server::Starter>.  For more information please refer to the documentation of the module.

=head1 OPTIONS

=head2 --port=(port|host:port)

TCP port to listen to (if omitted, will not bind to any ports)

=head2 --path=path

path at where to listen using unix socket (optional)

=head2 --dir=path

working directory, start_server do chdir to before exec (optional)

=head2 --interval=seconds

minimum interval to respawn the server program (default: 1)

=head2 --signal-on-hup=SIGNAL

name of the signal to be sent to the server process when start_server receives a SIGHUP (default: SIGTERM). If you use this option, be sure to also use C<--signal-on-term> below.

=head2 --signal-on-term=SIGNAL

name of the signal to be sent to the server process when start_server receives a SIGTERM (default: SIGTERM)

=head2 --pid-file=filename

if set, writes the process id of the start_server process to the file

=head2 --status-file=filename

if set, writes the status of the server process(es) to the file

=head2 --envdir=ENVDIR

directory that contains environment variables to the server processes.
It is intended for use with C<envdir> in C<daemontools>.
This can be overwritten by environment variable C<ENVDIR>.

=head2 --enable-auto-restart

enables automatic restart by time.
This can be overwritten by environment variable C<ENABLE_AUTO_RESTART>.

=head2 --auto-restart-interval=seconds

automatic restart interval (default 360). It is used with C<--enable-auto-restart> option.
This can be overwritten by environment variable C<AUTO_RESTART_INTERVAL>.

=head2 --kill-old-delay=seconds

time to suspend to send a signal to the old worker. The default value is 5 when C<--enable-auto-restart> is set, 0 otherwise.
This can be overwritten by environment variable C<KILL_OLD_DELAY>.

=head2 --restart

this is a wrapper command that reads the pid of the start_server process from --pid-file, sends SIGHUP to the process and waits until the server(s) of the older generation(s) die by monitoring the contents of the --status-file

=head2 --backlog
specifies a listen backlog parameter, whose default is SOMAXCONN (usually 128 on Linux). While SOMAXCONN is enough for most loads, large backlog is required for heavy loads.

=head2 --help

prints this help

=head2 --version

prints the version number

=head1 AUTHOR

Kazuho Oku

=head1 SEE ALSO

L<Server::Starter>

=head1 LICENSE

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

=cut