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contrib-munin/plugins/other/ntp_peers
2011-12-18 15:10:11 +01:00

221 lines
5.4 KiB
Perl
Executable File

#!/usr/bin/perl -w
# Plugin to monitor offsets to multiple NTP peers.
# NB currently only works for IPv4 peers
#
# (c)2008 Chris Hastie: chris (at) oak (hyphen) wood (dot) co (dot) uk
#
# Parameters understood:
#
# config (required)
# autoconf (optional - used by munin-node-configure)
#
# Config variables:
#
# ntpq - path to ntpq program
# statedir - directory in which to place state file
# hostname_<key> - override hostname for peer <key>. <key> is
# an IPv4 address with dots replaced by underscores.
# Useful for reference clocks, eg
# env.hostname_127_127_43_0 .GPS.
#
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
#
# Change log
# v1.0.0 2008-07-21 Chris Hastie
# initial release
#
#
#
# Magic markers - optional - used by installation scripts and
# munin-node-configure:
#
#%# family=contrib
#%# capabilities=autoconf
#
use strict;
use Socket;
my $NTPQ = $ENV{ntpq} || "ntpq";
my $COMMAND = "$NTPQ -np";
my $statedir = $ENV{statedir} || '/usr/local/var/munin/plugin-state';
my $statefile = "$statedir/ntp_peers.state";
# autoconf
if ($ARGV[0] and $ARGV[0] eq "autoconf") {
`$NTPQ -c help >/dev/null 2>/dev/null`;
if ($? eq "0") {
if (`$NTPQ -np | wc -l` > 0) {
print "yes\n";
exit 0;
} else {
print "no (unable to list peers)\n";
exit 1;
}
} else {
print "no (ntpq not found)\n";
exit 1;
}
}
my %peers;
# retrieve cached list of IPs and hostnames
if (-f "$statefile") {
open (IN, "$statefile") or exit 4;
while (<IN>) {
if (/^([0-9\.]+):(.*)$/) {
$peers{$1}{'name'} = $2;
}
}
close IN;
}
# do custom IP lookups
for my $key (map {/^hostname_(.+)/} keys %ENV) {
my $ip = &desanitize_field($key);
$peers{$ip}{'name'} = $ENV{"hostname_$key"}
}
# get data from ntpq
open(SERVICE, "$COMMAND |")
or die("Could not execute '$COMMAND': $!");
while (<SERVICE>) {
if (/^[-+*#](\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3})(\s+\S+){7}\s+(\S+)/) {
my $name = &lookupname($1);
$peers{$1}{'value'} = $3;
}
}
close(SERVICE);
# config
if ($ARGV[0] and $ARGV[0] eq 'config') {
print "graph_title NTP peer offsets\n";
print "graph_args --base 1000\n";
print "graph_vlabel ms\n";
print "graph_category ntp\n";
print "graph_info Offset (in ms) to the server's NTP peers\n";
print "graph_order ";
foreach my $key (sort by_name keys %peers) {
print &sanitize_field($peers{$key}{'name'}) . " ";
}
print "\n";
foreach my $peer (keys %peers) {
print &sanitize_field($peers{$peer}{'name'}) . ".label " . $peers{$peer}{'name'} . "\n";
}
exit 0;
}
# send output
foreach my $peer (keys %peers) {
print &sanitize_field($peers{$peer}{'name'}) . ".value " . &getpeeroffset($peer) . "\n";
}
# save list of peer IPs and hostnames
if(-l $statefile) {
die("$statefile is a symbolic link, refusing to touch it.");
}
open (OUT, ">$statefile") or exit 4;
foreach my $i (keys %peers) {
print OUT "$i:" . $peers{$i}{'name'} . "\n";
}
close OUT;
# sorts by hostname
sub by_name {
return $peers{$a}{'name'} cmp $peers{$b}{'name'};
}
# create a valid munin field name from the hostname
sub sanitize_field () {
my $field = shift;
# replace illegal characters with an underscore
$field =~ s/[^A-Za-z0-9_]/_/g;
# prepend an underscore if name starts with a number
$field =~ s/^([^A-Za-z_])/_$1/;
# truncate to 19 characters
if (length($field) > 19) {
$field = substr($field, 0, 19);
}
return $field
}
# get an IP address from the underscore escaped
# value of env.hostname_<key>
sub desanitize_field () {
my $field = shift;
$field =~ s/_/\./g;
return $field
}
# lookup hostnames
sub lookupname () {
my $ip = shift;
# have we already got it?
if ($peers{$ip}{'name'}) {
return $peers{$ip}{'name'};
}
# else look it up
my $iaddr = inet_aton($ip);
my $name = gethostbyaddr($iaddr, AF_INET) || $ip;
# add to cache
$peers{$ip}{'name'} = $name;
return $name;
}
# returns the offset, or U if it is undefined
sub getpeeroffset() {
my $ip = shift;
my $rtn = 'U';
if (exists($peers{$ip}{'value'})) {
$rtn = $peers{$ip}{'value'};
}
return $rtn
}
=pod
=head1 Description
ntp_peers - A munin plugin to monitor offsets to multiple NTP peers and
graph them on a single graph
=head1 Parameters understood:
config (required)
autoconf (optional - used by munin-node-configure)
=head1 Configuration variables:
All configuration parameters are optional
ntpq - path to ntpq program
statedir - directory in which to place state file
hostname_<key> - override hostname for peer <key>. <key> is
an IPv4 address with dots replaced by underscores.
Useful for reference clocks, eg
env.hostname_127_127_43_0 .GPS.
=head1 Known issues
ntp_peers will not monitor IPv6 peers
=cut