check_gitlabupdate

#!/usr/bin/perl -w

use strict;

#check_gitlabupdate.pl
#Nagios plugin to check if there is a new GitLab version available
#Version: 20140207
#Author:  Christoph Hoth <christoph.hoth@mashero.com>

#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/>.

#configuration
my $gitlab_path="/home/git/gitlab";
my $spoolfile="/var/spool/check_gitlabupdate";
my $allowed_lastcron_days=5;

my $debug=0;

#declare variables
my $cur_version;
my $new_version;
my $lastcron;

#get current version
open(VERSIONFILE,"< $gitlab_path/VERSION") or die "Unable to open $gitlab_path/VERSION";
while(<VERSIONFILE>){
  if($_=~/^([\d\.]+)$/){
    $cur_version=$1;
    last;
  }
}
close(VERSIONFILE);

#cancel if current version couldn't be determined
if(!$cur_version){
  print "UNKNOWN Unable to determine current version\n";
  exit 3;
}

$debug && print "Current version: $cur_version\n";

#read latest version from spoolfile
if(!open(SPOOLFILE,"<$spoolfile")){
  print "UNKNOWN Unable to open $spoolfile to get latest version number";
  exit 3;
}
while(<SPOOLFILE>){
  if($_=~/^(\d+) ([\d\.]+)$/){
    $lastcron=$1;
    $new_version=$2;
    last;
  }
}
close(SPOOLFILE);

#cancel if no latest tag found
if(!$new_version){
  print "UNKNOWN Unable to retrieve latest version number from spoolfile\n";
  exit 3;
}

$debug && print "Latest version:  $new_version\n";

#compare versions
my @cur=split(/\./,$cur_version);
my @new=split(/\./,$new_version);

my $arraycount=0;
if(@cur gt @new){$arraycount=@cur;}
else{$arraycount=@new;}

my $found=0;
for(my $i=0;$i<$arraycount;$i++){
  if($cur[$i]<$new[$i]){
    $found=1;
    last;
  }
}
if($found){
  print "WARNING New version available $new_version (current: $cur_version)\n";
  exit 1;
}else{
  #check if last cronjob check was running within the allowed time difference
  if($lastcron<(time()-$allowed_lastcron_days*86400)){
    print "WARNING Last successful check was running more than $allowed_lastcron_days days ago at ".localtime($lastcron)." (current version $cur_version)\n";
    exit 1;
  }else{
    print "OK GitLab is up to date ($cur_version)\n";
    exit 0;
  }
}