#!/usr/bin/perl -w
# -*- mode: cperl; cperl-indent-level: 8; -*-

=head1 NAME

chrony_sourcestats - Plugin to monitor Chrony offsets for various hosts.

=head1 CONFIGURATION

Plugin configuration parameters

[chrony_*]
 env.chronycpath /usr/local/bin/chronyc

  path to the chronyc executable

 env.timesources ntp1.example.org ntp2.example.com ntp1.example.net

  timesources - servers and peers that are used by the monitored
  chrony instance run the plugin as with 'suggest' as argument to see
  what timesoures might are available. e.g:

    munin-run --servicedir /etc/munin/plugins/  chrony_offsets suggest

  will produce a set of servers that can be used in the timesources
  environment variable.

  Note: use the same names as in the server and peer directives in
  your chrony configuration.

    env.freqlimit 0.7
    env.freqskewlimit 0.3
    env.offsetlimit 0.005
    env.stddevlimit 0.001

  By default the graphs are drawn using automatic scaling with these
  limits set the vertical scale of the graph will be bounded
  (rigidly). Note the values above are (reasonable) example values,
  not the default.

=head1 VERSION

 VERSION 0.1.1 - 2 Nov 2020

=head1 AUTHOR

Copyright (C) 2020 Olaf Kolkman

=head1 LICENSE

MIT

=head1 MAGIC MARKERS
Used by munin-node-configure.

 #%# family=manual
 #%# capabilities=multigraph

=head1 KNOWN ISSUES

There may be some issues when IP addresses are used instead of
hostnames in the timesources environment. Also, the names should match
those in the chrony config file.

=cut


use Munin::Plugin;
use English qw( -no_match_vars );
use strict;
use warnings;

my $retNetIP;
my $retNetDNS;
my $retDataVal;



BEGIN{
	# Import the namespaces for symbols used globally below
	if (! eval "require Net::IP;") {
		$retNetIP = "Net::IP";
	}else{
		Net::IP->import();
	}

	if (! eval "require Net::DNS;") {
		$retNetDNS = "Net::DNS";
	}

	if (! eval "require Data::Validate::IP;") {
		$retDataVal = "Data::Validate::IP";
	}else{
		Data::Validate::IP->import();
	}
}



need_multigraph();


my $chronyc = $ENV{'chrony'} || "/usr/local/bin/chronyc";
my $freqskewlimit = $ENV{'freqskewlimit'};
my $freqlimit = $ENV{'freqlimit'};
my $offsetlimit = $ENV{'offsetlimit'};
my $stddevlimit = $ENV{'stddevlimit'};

my @timesources= split(/\s+/,$ENV{'timesources'});


if ($ARGV[0] and $ARGV[0] eq "autoconf") {
        `$chronyc help >/dev/null 2>/dev/null`;
        if ($CHILD_ERROR eq "0") {
		if ($retNetIP || $retNetDNS || $retDataVal){
			print "no (missing perl libraries: ";
			print $retNetIP . " " if $retNetIP;
			print $retNetDNS . " " if $retNetDNS;
			print $retDataVal . " " if $retDataVal;
			print ")\n";
		}
                if (`$chronyc -n sources | wc -l` > 0) {
                        print "yes\n";
                        exit 0;
                } else {
                        print "no (chronyc sources returned no sources)\n";
                        exit 0;
		}
	} else {
		print "no (chronyc not found)\n";
		exit 0;
	}
}

if ($ARGV[0] and $ARGV[0] eq "suggest") {
	print "env.timesources ";
        foreach my $line (`$chronyc -n sources`) {
                if ($line =~ m/^??\s+\S+\s+\d+/) {
                        my (undef, $peer_addr , undef, undef, undef, undef, undef, undef, undef) = split(/\s+/, $line);
                        unless (( $peer_addr eq "0.0.0.0") ){
				my $hostname;
				if (is_ip($peer_addr) and  $hostname = `$chronyc sourcename $peer_addr`){
					chop $hostname;
					print $hostname . " ";
				}else{
					# Bit of a last resort, not sure if this path is ever triggered.
					my $resolver = Net::DNS::Resolver->new;
					$resolver->tcp_timeout(5);
					$resolver->udp_timeout(5);
					my $query = $resolver->search($peer_addr, "PTR");
					if ($query) {
						foreach my $rr ($query->answer) {
							if ("PTR" eq $rr->type) {
								print $hostname=$rr->ptrdname."\n";
							}
						}
					}
				}
				print $peer_addr."\n" unless $hostname;
			}

                }
        }
	print "\n";
        exit 0;
}



$0 =~ /chrony_(.+)*$/;
my $name = $1;


die "You should set env.timesources (try running munin-run --servicedir /etc/munin/plugins/  chrony_offsets suggest)" unless @timesources;

if ($ARGV[0] and $ARGV[0] eq "config") {

	print "multigraph chrony_freq\n";
	# Using Chrony Sourcestats: <no> title to enforce an order in the presentation.
	print "graph_title CHRONY Sourcestats: 1. Residual Frequency\n";
	print "graph_args --base 1000 --vertical-label PPM ";
		if ($freqlimit) {
			print "--lower-limit -$freqlimit --upper-limit $freqlimit --rigid\n";
	}else{
		print "\n";
	}

	print "graph_category time\n";
	foreach my $source (@timesources){
		my $fldname=clean_fieldname($source)."_";
		print "$fldname"."freq.label $source \n";
		print "$fldname"."freq.cdef $fldname"."freq,1,*\n";

	}


	print "multigraph chrony_freqsk\n";
	print "graph_title CHRONY Sourcestats: 2. Frequency Skew\n";
	print "graph_args --base 1000 --vertical-label PPM --lower-limit 0 ";
	if ($freqskewlimit) {
		print "--upper-limit $freqskewlimit --rigid\n";
	}else{
		print "\n";
	}
	print "graph_category time\n";
	foreach my $source (@timesources){
		my $fldname=clean_fieldname($source)."_";
		print "$fldname"."freqsk.label $source \n";
		print "$fldname"."freqsk.cdef $fldname"."freqsk,1,*\n";

	}



	print "multigraph chrony_offset\n";
	print "graph_title CHRONY Sourcestats: 3. Offset\n";
	print "graph_args --base 1000 --vertical-label seconds ";
		if ($offsetlimit) {
		print "--lower-limit -$offsetlimit --upper-limit $offsetlimit --rigid\n";
	}else{
		print "--lower-limit 0\n";
	}

	print "graph_category time\n";
	foreach my $source (@timesources){
		my $fldname=clean_fieldname($source)."_";
		print "$fldname"."offset.label $source \n";
		print "$fldname"."offset.cdef $fldname". "offset,1,*\n";

	}

	print "multigraph chrony_stdev\n";
	print "graph_title CHRONY Sourcestats: 4 Estimated Standard Deviation\n";
	print "graph_args --base 1000 --vertical-label seconds --lower-limit 0 ";
	if ($stddevlimit) {
		print "--upper-limit $stddevlimit --rigid\n";
	}else{
		print "\n";
	}

	print "graph_category time\n";
	foreach my $source (@timesources){
		my $fldname=clean_fieldname($source)."_";
		print "$fldname"."stdev.label $source \n";
		print "$fldname"."stdev.cdef $fldname"."stdev,1,*\n";

	}



	exit 0;

}



my $datastore;

my @associations = `$chronyc -n sourcestats`;

foreach my $line (@associations) {
	if ($line =~ m/^??\s+\S+\s+\d+/) {
		my ( $srcadr , undef, undef, undef, $freq, $freqsk, $offset, $stddev) = split(/\s+/, $line);
		my $srcname=match_sourcename($srcadr);
		@{$datastore->{$srcname}}=($freq,$freqsk,$offset,$stddev) if $srcname;
	}
}



sub match_sourcename {
	my $srcadr=shift;
	my $matched = 0;
	my $sourcename="";
	if ( is_ip($srcadr) ) {
		$sourcename=`$chronyc sourcename $srcadr`;
		chop $sourcename;
		return  $sourcename if $sourcename;
	};
	# return the src address and deal with it later.
	return $srcadr;
}


print "multigraph chrony_freq\n";
foreach (@timesources){
	if (exists $datastore->{$_}){
		my $fldname=clean_fieldname($_)."_";
		my $freq=$datastore->{$_}->[0];
		print "$fldname"."freq.value $freq \n";
	}
}

print "\n\n";


print "multigraph chrony_freqsk\n";
foreach (@timesources){
	if (exists $datastore->{$_}){
		my $fldname=clean_fieldname($_)."_";
		my $freqsk=$datastore->{$_}->[1];
		print "$fldname"."freqsk.value $freqsk \n";
	}

}


print "\n\n";


print "multigraph chrony_offset\n";
foreach (@timesources){
	if (exists $datastore->{$_}){
		my $fldname=clean_fieldname($_)."_";
		my $offset=$datastore->{$_}->[2];
		if ($offset =~ /(.?\d+)(\S+)/){
			$offset=$1*1e-3 if $2 eq "ms";
			$offset=$1*1e-6 if $2 eq "us";
			$offset=$1*1e-9 if $2 eq "ns";
		}
		print "$fldname"."offset.value $offset\n";
	}

}


print "\n\n";


print "multigraph chrony_stdev\n";
foreach (@timesources){
	if (exists $datastore->{$_}){
		my $fldname=clean_fieldname($_)."_";
		my $stdev=$datastore->{$_}->[3];
		if ($stdev =~ /(.?\d+)(\S+)/){
			$stdev=$1*1e-3 if $2 eq "ms";
			$stdev=$1*1e-6 if $2 eq "us";
			$stdev=$1*1e-9 if $2 eq "ns";
		}
		print "$fldname"."stdev.value $stdev\n";
	}

}








exit 0;


# MIT License
# 
# Copyright (c) 2020 Olaf M. Kolkman
# 
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
# 
# The above copyright notice and this permission notice shall be included in all
# copies or substantial portions of the Software.
# 
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.