#! /usr/bin/perl -w

=head1 NAME

nutups2_ - Plugin to monitor UPSes managed by NUT

=head1 CONFIGURATION

Generally none needed.

If you have installed NUT at a non-standard location, then you can specify its
location like:

  [nutups2_*]
    env.upsc /some/location/bin/upsc

=head1 WARNING AND CRITICAL SETTINGS

If upsc reports 'high' and 'low' values for some attribute, those will used
as the critical range. Otherwise the following environment variables can be
used to set the defaults for all fields:

    env.warning
    env.critical

You can also control individual fields like:

    env.input_L1.warning
    env.output.critical

=head1 MAGIC MARKERS

 #%# family=auto
 #%# capabilities=autoconf suggest

=head1 FEATURES

The plugin supports reporting battery charge, UPS load, input/output
frequencies/currents/voltages, apparent and real power output, humidity and
temperature readings. Note however that different UPS models report different
levels of detail; the plugin reports whatever information the NUT UPS driver
(and in turn the UPS itself) provides.

Although the 'suggest' command will only offer UPSes for which the local host
is the master, you can also monitor remote UPSes if you include the host name
in the symlink, like:

	nutups2_<upsname>@<hostname or address>_frequency

etc.

=head1 AUTHOR

Gábor Gombás <gombasg@sztaki.hu>

=head1 LICENSE

GPLv2 or later

=cut

use strict;
use Munin::Plugin;
use Carp;

my $UPSC = $ENV{'upsc'} || 'upsc';

# For the 'filter' field, the first sub-match should contain the name to
# display, and the second sub-match should indicate if it is a nominal
# value instead of a sensor reading.
my %config = (
	charge => {
		filter => qr/^(.*)\.(?:charge|load)$/,
		title => 'UPS load and battery charge',
		args => '--base 1000 -l 0 -u 100',
		vlabel => '%',
		config => \&common_config,
		fetch => \&common_fetch,
	},
	current => {
		filter => qr/^(.*)\.current(\.nominal)?$/,
		title => 'UPS current',
		args => '--base 1000 -l 0',
		vlabel => 'Amper',
		config => \&common_config,
		fetch => \&common_fetch,
	},
	frequency => {
		filter => qr/^(.*)\.frequency(\.nominal)?$/,
		title => 'UPS frequency',
		args => '--base 1000 -l 0',
		vlabel => 'Hz',
		config => \&common_config,
		fetch => \&common_fetch,
	},
	humidity => {
		filter => qr/^(.*)\.humidity$/,
		title => 'UPS humidity',
		args => '--base 1000 -l 0',
		vlabel => '%',
		config => \&common_config,
		fetch => \&common_fetch,
	},
	power => {
		filter => qr/^(.*)\.power(\.nominal)?$/,
		title => 'UPS apparent power',
		args => '--base 1000 -l 0',
		vlabel => 'VA',
		config => \&common_config,
		fetch => \&common_fetch,
	},
	realpower => {
		filter => qr/^(.*)\.realpower(\.nominal)?$/,
		title => 'UPS real power',
		args => '--base 1000 -l 0',
		vlabel => 'Watt',
		config => \&common_config,
		fetch => \&common_fetch,
	},
	temperature => {
		filter => qr/^(.*)\.temperature$/,
		title => 'UPS temperature',
		args => '--base 1000 -l 0',
		vlabel => 'Celsius',
		config => \&common_config,
		fetch => \&common_fetch,
	},
	voltage => {
		filter => qr/^(.*)\.voltage(\.nominal)?$/,
		title => 'UPS voltage',
		args => '--base 1000 -l 0',
		vlabel => 'Volt',
		config => \&common_config,
		fetch => \&common_fetch,
	},
);

sub read_ups_values {
	my $ups = shift;

	my @lines = `$UPSC $ups 2>/dev/null`;
	my $values = {};
	for my $line (@lines) {
		chomp $line;

		my ($key, $value) = $line =~ m/^([^:]+):\s+(\S.*)$/;
		$values->{$key} = $value;
	}
	return $values;
}

sub graph_config {
	my ($func, $ups, $values) = @_;

	print "graph_title " . $config{$func}->{'title'} . " ($ups)\n";
	print "graph_vlabel " . $config{$func}->{'vlabel'} . "\n";
	print "graph_args " . $config{$func}->{'args'} . "\n";
	print "graph_category sensors\n";

	my @info;
	push @info, 'Manufacturer: "' . $values->{'ups.mfr'} . '"'
		if exists $values->{'ups.mfr'} and $values->{'ups.mfr'} ne 'unknown';
	push @info, 'Model: "' . $values->{'ups.model'} . '"'
		if exists $values->{'ups.model'};
	push @info, 'Serial: "' . $values->{'ups.serial'} . '"'
		if exists $values->{'ups.serial'};
	map { s/\s+/ /g } @info;
	print "graph_info " . join(', ', @info) . "\n"
		if @info;
}

sub print_range_warning {
	my ($id, $key, $values) = @_;

	if (exists $values->{$key . '.minimum'}) {
		print $id . ".min " . $values->{$key . '.minimum'} . "\n";
	}
	if (exists $values->{$key . '.maximum'}) {
		print $id . ".max " . $values->{$key . '.maximum'} . "\n";
	}

	my $range = '';
	if (exists $values->{$key . '.high'}) {
		$range = $values->{$key . '.high'};
	}
	if (exists $values->{$key . '.low'}) {
		$range = $values->{$key . '.low'} . ':' . $range;
	}
	# print_thresholds() needs 'undef' for no range
	undef $range unless $range;
	print_thresholds($id, undef, undef, undef, $range);
}

# Example keys for voltages:
#	battery.voltage
#	battery.voltage.minimum
#	battery.voltage.maximum
#	battery.voltage.nominal
#	input.voltage
#	input.voltage.minimum
#	input.voltage.maximum
#	input.bypass.L1-N.voltage
#	input.L1-N.voltage
#	output.voltage
#	output.voltage.nominal
#	output.L1-N.voltage
#
# Replace 'voltage' with 'current' in the above list to get an example
# for current keys.
#
# Frequency keys:
#	input.frequency
#	input.frequency.nominal
#	input.bypass.frequency
#	input.bypass.frequency.nominal
#	output.frequency
#	output.frequency.nominal
#	output.frequency.minimum
#	output.frequency.maximum
sub common_config {
	my ($func, $ups) = @_;

	my $values = read_ups_values($ups);
	graph_config($func, $ups, $values);
	for my $key (sort keys %$values) {
		my ($field, $nominal) = $key =~ $config{$func}->{'filter'};
		next unless $field;

		$field .= $nominal if $nominal;
		my $id = clean_fieldname($field);

		# These labels look better this way and are still short enough
		$field = $key if $func =~ m/(charge|temperature|humidity)/;

		# Beautification
		$field = ucfirst($field);
		$field =~ s/\./ /g;

		print $id . ".label " . $field . "\n";
		print $id . ".type GAUGE\n";

		# Draw nominal values a litle thinner
		print $id . ".draw LINE1\n" if $nominal;

		print_range_warning($id, $key, $values);
	}
}

sub common_fetch {
	my ($func, $ups) = @_;

	my $values = read_ups_values($ups);
	for my $key (sort keys %$values) {
		my ($field, $nominal) = $key =~ $config{$func}->{'filter'};
		next unless $field;

		$field .= $nominal if $nominal;
		my $id = clean_fieldname($field);

		print $id . ".value " . $values->{$key} . "\n";
	}
}

if ($ARGV[0] and $ARGV[0] eq 'autoconf') {
	# The former nutups_ plugin parsed upsmon.conf. But for a large UPS
	# that powers dozens or hundreds of machines, that would mean
	# monitoring the same UPS from every host it powers, which does not
	# make sense. Using upsc and defaulting to localhost means that
	# 'autoconf' will only enable the plugin on the UPS master node, where
	# upsd is running.
	my @upses = `$UPSC -l 2>/dev/null`;
	if ($?) {
		if ($? == -1) {
			print "no (program '$UPSC' was not found)\n";
		}
		else {
			print "no (program '$UPSC -l' returned error)\n";
		}
		exit 0;
	}

	map { chomp $_ } @upses;
	unless (@upses and $upses[0]) {
		print "no (program '$UPSC' listed no units)\n";
	}
	else {
		print "yes\n";
	}
	exit 0;
}

if ($ARGV[0] and $ARGV[0] eq 'suggest') {
	my @upses = `$UPSC -l 2>/dev/null`;
	for my $ups (@upses) {
		chomp $ups;
		for my $metric (keys %config) {
			my $values = read_ups_values($ups);
			my @keys = grep { +$_ =~ $config{$metric}->{'filter'} } keys(%$values);
			print $ups . '_' . $metric . "\n" if @keys;
		}
	}
	exit 0;
}

croak("Unknown command line arguments") if $ARGV[0] and $ARGV[0] ne 'config';

# The UPS name may contain underscores
my $fn_re = join('|', keys %config);
my ($ups, $func) = $0 =~ m/nutups2_(.*)_($fn_re)$/;

if ($ARGV[0] and $ARGV[0] eq 'config') {
	$config{$func}->{'config'}($func, $ups);
}
else {
	$config{$func}->{'fetch'}($func, $ups);
}

exit 0;