helios_service_status

#!/usr/bin/env perl

use 5.008;
use strict;
use warnings;
use Getopt::Long;
use Sys::Hostname ();

use Helios::Service;

our $VERSION = '2.82';

our $Service_Name = '';
our $Hostname     = '';
our $Help_Mode    = 0;
our $OPT_Epoch_Time = 0;

GetOptions(
	"service=s"  => \$Service_Name,
	"H|hostname=s" => \$Hostname,
	"epoch-time" => \$OPT_Epoch_Time, 
	"help"       => \$Help_Mode,
);

# help mode
if ($Help_Mode) {
	require Pod::Usage;
	Pod::Usage::pod2usage(-verbose => 2, -exitstatus => 0);
}

# this is a little old school, but we'll 
# instantiate the base Helios::Service to 
# get a collective database connection
my $s = Helios::Service->new();
$s->prep();
my $dbh = $s->dbConnect();

my @placeholders;
my $sql = q{
	SELECT 
		worker_class, 
		worker_version, 
		host, 
		process_id, 
		start_time, 
		register_time
	FROM
		helios_worker_registry_tb
	WHERE
		register_time > ?
		
};
push(@placeholders, time() - 300 );

if ($Service_Name) { 
	$sql .= ' AND worker_class = ? ';
	push(@placeholders, $Service_Name);
}

if ($Hostname && $Hostname ne '*') {
	$sql .= ' AND host = ? ';
	push(@placeholders, $Hostname);
} elsif ($Hostname eq '*'){
	# do nothing
} else {
	# --hostname wasn't specified, default to the localhost
	$sql .= ' AND host = ? ';
	push(@placeholders, Sys::Hostname::hostname());	
}

my $rs;
eval {
	$rs = $dbh->selectall_arrayref($sql, undef, @placeholders);
	1;
} or do {
	my $E = $@;
	warn "$0: ERROR: $E\n";
	exit(1);
};

foreach (@$rs) {
	print 'Service: ',$_->[0],"\n";
	if (!defined($_->[1]) || $_->[1] eq '') {
		print "Version: (none)\n";
	} else {
		print 'Version: ',$_->[1],"\n";
	}
	print 'Host: ',$_->[2],"\n";
	print 'PID: ',$_->[3],"\n";
	print "Online Since: ", $OPT_Epoch_Time ? $_->[4] : scalar localtime($_->[4]),"\n";
	print 'Last Registered: ', $OPT_Epoch_Time ? $_->[5] : scalar localtime($_->[5]),"\n";
	print "\n";
}

$dbh->disconnect();


exit(0);


=head1 NAME

helios_service_status - check the status of services running in a Helios collective

=head1 SYNOPSIS

 helios_service_status [--service=<service name>] [--hostname=<hostname>] [--epoch-time]
 
 # list status of all service instances running on current host
 helios_service_status 
 
 # list status of all service instances running on host wrkhost1
 helios_service_status --hostname=wrkhost1
 
 # list status of all service instances running on all hosts in the collective
 helios_service_status --hostname=*
 
 # list status of all instances of MyService
 # -H is shortcut for --hostname
 helios_service_status --service=MyService -H=*

 # list information on the MyService instance running on wrkhost1
 # report the start and last check in times in epoch seconds
 helios_service_status -s MyService -H wrkhost1 --epoch-time

=head1 DESCRIPTION

The helios_service_status command reports status information on services 
running in a Helios collective.  You can use this command for general 
administration purposes or to build monitoring scripts for services.

The helios_service_status command currently reports 6 key pieces of 
information:

=over 4

=item Service

name of the service.

=item Version

the version of the service, if one is set.

=item Host

the hostname of the host on which the service is running.

=item PID

The process id of the service daemon.

=item Online Since

the start time of the service daemon.

=item Last Registered

the last time the service daemon "checked in" to the collective.  How often 
this happens is controlled by the "registration_interval" configuration 
parameter.  The default is 60 sec, which should be fine for most purposes.

=back

This command basically reports the same type of information as the 
Helios::Panoptes Collective Admin view, but having it available at the 
command line adds convenience and enhances the Helios system's scriptability.

=head1 AUTHOR

Andrew Johnson, E<lt>lajandy at cpan dot orgE<gt>

=head1 COPYRIGHT AND LICENSE

Copyright (C) 2013-4 by Logical Helion, LLC.

This library is free software; you can redistribute it and/or modify
it under the same terms as Perl itself, either Perl version 5.8.0 or,
at your option, any later version of Perl 5 you may have available.

=head1 WARRANTY

This software comes with no warranty of any kind.

=cut