# -*- perl -*- package Smokeping::Master; use HTTP::Request; use Data::Dumper; use Storable qw(nstore_fd dclone fd_retrieve); use strict; use warnings; use Fcntl qw(:flock); use Digest::MD5 qw(md5_base64); =head1 NAME Smokeping::Master - Master Functionality for Smokeping =head1 OVERVIEW This module handles all special functionality required by smokeping running in master mode. =head2 IMPLEMENTATION =head3 slave_cfg=extract_config(cfg,slave) Extract the relevant configuration information for the selected slave. The configuration will only contain the information that is relevant for the slave. Any parameters overwritten in the B<Slaves> section of the configuration file will be patched for the slave. =cut sub get_targets; sub get_targets { my $trg = shift; my $slave = shift; my %return; my $ok; foreach my $key (keys %{$trg}){ # dynamic hosts can only be queried from the # master next if $key eq 'host' and $trg->{$key} eq 'DYNAMIC'; next if $key eq 'host' and not ( defined $trg->{slaves} and $trg->{slaves} =~ /\b${slave}\b/); if (ref $trg->{$key} eq 'HASH'){ $return{$key} = get_targets ($trg->{$key},$slave); $ok = 1 if defined $return{$key}; } else { $ok = 1 if $key eq 'host'; $return{$key} = $trg->{$key}; } } return ($ok ? \%return : undef); } sub extract_config { my $cfg = shift; my $slave = shift; # get relevant Targets my %slave_config; $slave_config{Database} = dclone $cfg->{Database}; $slave_config{General} = dclone $cfg->{General}; $slave_config{Probes} = dclone $cfg->{Probes}; $slave_config{Targets} = get_targets($cfg->{Targets},$slave); $slave_config{__last} = $cfg->{__last}; if ($cfg->{Slaves} and $cfg->{Slaves}{$slave} and $cfg->{Slaves}{$slave}{override}){ for my $override (keys %{$cfg->{Slaves}{$slave}{override}}){ my $node = \%slave_config; my @keys = split /\./, $override; my $last_key = pop @keys; for my $key (@keys){ $node->{$key} = {} unless $node->{$key} and ref $node->{$key} eq 'HASH'; $node = $node->{$key}; } $node->{$last_key} = $cfg->{Slaves}{$slave}{override}{$override}; } } if ($slave_config{Targets}){ return Dumper \%slave_config; } else { return undef; } } =head3 save_updates (updates) When the cgi gets updates from a client, these updates are saved away, for each 'target' so that the updates can be integrated into the relevant rrd database by the rrd daemon as the next round of updates is processed. This two stage process is chosen so that all results flow through the same code path in the daemon. =cut sub save_updates { my $cfg = shift; my $slave = shift; my $updates = shift; # name\ttime\tupdatestring # name\ttime\tupdatestring for my $update (split /\n/, $updates){ my ($name, $time, $updatestring) = split /\t/, $update; my $file = $cfg->{General}{datadir}."/${name}.slave_cache"; if ( ! -f $cfg->{General}{datadir}."/${name}.rrd" ){ warn "Skipping update for ${name}.slave_cache since $cfg->{General}{datadir}/${name}.rrd does not exist in the local data structure. Make sure you run the smokeping daemon. ($cfg->{General}{datadir})\n"; } elsif ( open (my $hand, '+>>', $file) ) { if ( flock $hand, LOCK_EX ){ my $existing; if ( tell $hand > 0 ){ seek $hand, 0,0; eval { $existing = fd_retrieve $hand }; if ($@) { #error warn "Loading $file: $@"; $existing = []; } }; push @{$existing}, [ $slave, $time, $updatestring]; seek $hand, 0,0; truncate $hand, 0; nstore_fd ($existing, $hand); flock $hand, LOCK_UN; } else { warn "Could not lock $file. Can't store data.\n"; } close $hand; } else { warn "Could not update $file: $!"; } } }; =head3 get_slaveupdates Read in all updates provided by slaves and return an array reference. =cut sub get_slaveupdates { my $name = shift; my $file = $name.".slave_cache"; my $data; if ( open (my $hand, '<', $file) ) { if ( flock $hand, LOCK_EX ){ eval { $data = fd_retrieve $hand }; if ($@) { #error warn "Loading $file: $@"; return; } unlink $file; flock $hand, LOCK_UN; } else { warn "Could not lock $file. Can't load data.\n"; } close $hand; return $data; } return; } =head3 get_secret Read the secrtes file and figure the secret for the slave which is talking to us. =cut sub get_secret { my $cfg = shift; my $slave = shift; if (open my $hand, "<", $cfg->{Slaves}{secrets}){ while (<$hand>){ next unless /^${slave}:(\S+)/; close $hand; return $1; } } warn "WARNING: Opening $cfg->{Slaves}{secrets}: $!\n"; return; } =head3 answer_slave Answer the requests from the slave by accepting the data, verifying the secrets and providing updated config information if necessary. =cut sub answer_slave { my $cfg = shift; my $q = shift; my $slave = $q->param('slave'); my $secret = get_secret($cfg,$slave); if (not $secret){ print "Content-Type: text/plain\n\n"; print "WARNING: No secret found for slave ${slave}\n"; return; } my $key = $q->param('key'); my $data = $q->param('data'); my $config_time = $q->param('config_time'); if (not ref $cfg->{Slaves}{$slave} eq 'HASH'){ print "Content-Type: text/plain\n\n"; print "WARNING: I don't know the slave ${slave} ignoring it"; return; } # lets make sure the we share a secret if (md5_base64($secret.$data) eq $key){ save_updates $cfg, $slave, $data; } else { print "Content-Type: text/plain\n\n"; print "WARNING: Data from $slave was signed with $key which does not match our expectation\n"; return; } # does the client need new config ? if ($config_time < $cfg->{__last}){ my $config = extract_config $cfg, $slave; if ($config){ print "Content-Type: application/smokeping-config\n"; print "Key: ".md5_base64($secret.$config)."\n\n"; print $config; } else { print "Content-Type: text/plain\n\n"; print "WARNING: No targets found for slave '$slave'\n"; return; } } else { print "Content-Type: text/plain\n\nOK\n"; }; return; } 1; __END__ =head1 COPYRIGHT Copyright 2007 by Tobias Oetiker =head1 LICENSE 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 2 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, write to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. =head1 AUTHOR Tobias Oetiker E<lt>tobi@oetiker.chE<gt> =cut