#!/usr/bin/perl -w
# -*- perl -*-

use strict;

=head1 NAME

freeradius_sqlippools_ - Plugin to monitor IP pool utilisation

=head1 CONFIGURATION

This is a wildcard plugin to support fetching the status of multiple sqlippool
instances.

It can also be linked directly (as with a non-wildcard plugin) to present a
combined graph showing the percentage utilisation of all pools.

It is likely that a common configuration will apply to all plugins but this
doesn't have to be so:

    [freeradius_sqlippools_*]
        env.fr_driver mysql
        env.fr_host 192.0.2.1
        env.fr_port 3306
        env.fr_db radius
        env.fr_user radius
        env.fr_pass radpass

fr_driver is the name of the Perl DBI driver used in the DSN connection string.
The corresponding DBD module for the driver must be installed.

You should omit fr_pass and specify fr_passfile to avoid placing the password
in a plugin configuration file that is world accessible, e.g.:

    [freeradius_sqlippools_mypool]
        user radmonitor
        group radmonitor
        env.fr_driver Pg
        env.fr_host 192.0.2.2
        env.fr_port 5432
        env.fr_db radius
        env.fr_user radmonitor
        env.fr_passfile /home/radmonitor/db_pass.txt

=head1 AUTHORS

Original Author: Network RADIUS

=head1 LICENSE

GPLv2

=head1 MAGIC MARKERS

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

=cut


use File::Basename;
use Storable qw(lock_store lock_retrieve);
use DBI;

use constant STATEFILE => "$ENV{MUNIN_PLUGSTATE}/freeradius_sqlippools.state";

use constant SQL => <<'EOF';
SELECT
	DISTINCT pool_name AS pool_name,
	COUNT(id) OVER (PARTITION BY pool_name) AS total,
	SUM(CASE WHEN expiry_time > NOW() THEN 1 ELSE 0 END) OVER (PARTITION BY pool_name) AS used
FROM radippool
EOF

my $script = basename($0);
(my $instance) = $script =~ /freeradius_sqlippools_(.+)/;
my $command = $ARGV[0] || 'show';

autoconf() if $command eq 'autoconf';
suggest() if $command eq 'suggest';
config_instance($instance) if $command eq 'config' && defined $instance;
config_combined() if $command eq 'config' && !defined $instance;
show_instance($instance) if $command eq 'show' && defined $instance;
show_combined() if $command eq 'show' && !defined $instance;

exit;


sub autoconf {
	my $results;
	eval {
		$results = get_pools(1);
	};
	if ($results) {
		print "yes\n";
	} else {
		print "no (Failed to read pool status from database)\n";
	}
}

sub suggest {
	my $pools = get_pools(1);
	return unless defined $pools;
	print "$_\n" foreach keys %{$pools};
}

sub config_instance {
	my $instance = shift;

	print <<EOF;
graph_title FreeRADIUS SQL IP pool ($instance)
graph_category Other
graph_args -l 0
total.label Total IPs
total.draw AREA
used.label Allocated IPs
used.draw AREA
EOF
}

sub config_combined {

	print <<EOF;
graph_title FreeRADIUS SQL IP pools
graph_category Other
graph_args -l 0 -u 100
graph_vlabel Utilisation (%)
EOF

	my $pools = get_pools();
	foreach (keys %{$pools}) {
		print "$_.label Pool: $_\n";
		print "$_.warning 90\n";
		print "$_.critical 95\n";
	}
}

sub show_instance {
	my $instance = shift;
	my $pool = get_pools()->{$instance};
	print "total.value $pool->{total}\n";
	print "used.value $pool->{used}\n";
}

sub show_combined {
	my $pools = get_pools();
	foreach (keys %{$pools}) {
		my $util = $pools->{$_}->{used} * 100 / $pools->{$_}->{total};
		print "$_.value $util\n";
	}
}

sub get_pools {

	my $no_cache = shift;  # Ensure that caching doesn't interfere with reconfiguration

	# Read results from the cache unless stale or told not to
	if (!$no_cache && -e STATEFILE && -M STATEFILE < 60/86400) {
		return lock_retrieve(STATEFILE);
	}

	my $driver   = $ENV{'fr_driver'} || 'mysql';
	my $host     = $ENV{'fr_host'}   || '127.0.0.1';
	my $port     = $ENV{'fr_port'}   || '3306';
	my $db       = $ENV{'fr_db'}     || 'radius';
	my $user     = $ENV{'fr_user'}   || 'radius';
	my $pass     = $ENV{'fr_pass'}   || 'radpass';
	my $passfile = $ENV{'fr_passfile'};

	# Read password from a file
	if (!defined $pass && defined $passfile) {
		open (my $FH, '<', $passfile) || die "Failed to open fr_passfile: $passfile";
		$pass = <$FH>;
		chomp $pass;
		close $FH;
	}

	my $dsn;
	if ($driver eq 'Oracle') {
		$dsn = "DBI:$driver:$db";
	} else {
		$dsn = "DBI:$driver:database=$db;host=$host";
	}
	$dsn .= ";port=$port" if $port;

	# Read the results by running our query against the database
	my $dbh = DBI->connect($dsn, $user, $pass, { RaiseError => 1, PrintError => 0, AutoCommit => 1 });
	my $sth = $dbh->prepare(SQL);
	$sth->execute();
	my $results=$sth->fetchall_hashref('pool_name');
	$sth->finish();
	$dbh->disconnect();

	# Cache the results
	if (!$no_cache && $results) {
		lock_store($results,STATEFILE);
	}

	return $results;

}

# vim:syntax=perl