Nagios

Non-HTTP-based monitoring script

. /usr/lib/nagios/plugins/utils.sh

# Where the archive is.
TO=/srv/ftp.root/ubuntu
HOSTNAME=$(hostname -f)
STAMP=${TO}/project/trace/${HOSTNAME}
WARN=6
CRITICAL=12

while [ $# -gt 0 ]
do 
        case "$1" in
                -c|--critical)  CRITICAL=$2; shift; shift;;
                -w|--warn)      WARN=$2; shift; shift;;
                --)     shift; break;;
                -*)     echo "You lost me at '$1'"; exit 1;;
                *)      STAMP=$1; shift; break;;
        esac
done

HOUR=$[ 60 * 60 ] # Hour of seconds
NOW=$(date +%s) # Unix time
STAMPAGE=$[ $NOW - $(stat -c %Y ${STAMP}) ]
STAMPHOURS=$[ $STAMPAGE / $HOUR ]

echo "$STAMP is over $STAMPHOURS hours old."

if [ $STAMPHOURS -lt $WARN ]; then
        exit $STATE_OK
elif [ $STAMPHOURS -lt $CRITICAL ]; then
        exit $STATE_WARNING
else
        exit $STATE_CRITICAL
fi

HTTP-based monitoring script

This check is suitable for Nagios installations. It will do a HEAD-request on the requested file on both your webserver and the main webserver and calculate the time-difference between the two last-modified headers.

Call this script as follows:

define command {
        command_name    check_ubuntu
        command_line    /etc/nagios-plugins/custom/check_ubuntu $HOSTNAME$ $ARG1$ $ARG2$
        }

And:

define service{
        use                             generic-service
        host_name                       <your mirrors hostname>
        service_description             Mirror status
        check_command                   check_ubuntu!<hostname of main mirror>!<file to check>!<mode, archive or cd>
}

Good files to check are:

ubuntu/ls-lR.gz for archive mirrors
.pool/MD5SUMS for releases mirrors

# Create a user agent object
use LWP::UserAgent;
use Net::DNS;
use Date::Parse;
use strict;
use lib "/usr/lib/nagios/plugins";
use utils qw($TIMEOUT %ERRORS &print_revision &support);

my ($host, $file, $mode) = @ARGV;

my $resolver = Net::DNS::Resolver->new;

my $dnsquery = $resolver->search($host);

if ($dnsquery) {
    foreach my $rr ($dnsquery->answer) {
        next unless $rr->type eq "A";
        if ($rr->address =~ /91\.189\.91|185\.125\.190/) {
                print "OK - Mirror ok (runs at Canonical)";
                exit $ERRORS{"OK"};
        }
    }
} else {
        print "CRITICAL - Cannot resolve hostname $host";
        exit $ERRORS{"CRITICAL"};
}

my $ua = LWP::UserAgent->new;
$ua->agent("UbuntuMirrorCheck/0.1 ");

my $canonicalhost = $host;
my $canonicalfile;
if ($canonicalhost =~ m/(archive|releases)\.ubuntu\.com/) {
        $canonicalhost =~ s/^..\.//;
        $canonicalfile = $file;
} else {
        if (defined($mode) && $mode =~ m/archive/) {
                $canonicalhost = 'archive.ubuntu.com';
                $canonicalfile = 'ubuntu/ls-lR.gz';
        } elsif (defined($mode) && $mode =~ m/cd/) {
                $canonicalhost = 'releases.ubuntu.com';
                $canonicalfile = '.pool/MD5SUMS';
        } else {
                print "CRITICAL - Cannot figure out the mode from hostname $host, and mode is not set";
                exit $ERRORS{"CRITICAL"};
        }
}


# Create a request
my $canonical = HTTP::Request->new(HEAD => 'http://'.$canonicalhost.'/'.$canonicalfile);
my $mirror    = HTTP::Request->new(HEAD => 'http://'.$host.'/'.$file);

# Pass request to the user agent and get a response back
my $canonical_res = $ua->request($canonical);
my $mirror_res    = $ua->request($mirror);

# Check the outcome of the response
if ($mirror_res->is_success) {
        my $canonical_time = str2time($canonical_res->header('last-modified'));
        my $mirror_time    = str2time($mirror_res->header('last-modified'));

        if (!defined($mirror_time)) {
                print "OK - Unable to determine mirror's last-modified timestamp";
                exit $ERRORS{"OK"};
        }

        if ($mirror_time > $canonical_time) {
                print "WARNING - Mirror seems to live in the future";
                exit $ERRORS{"WARNING"};
        } else {
                my $diff = $canonical_time - $mirror_time;
                my ($rest, $days, $hours, $minutes, $seconds) = (0, 0, 0, 0, 0);
                $days = int($diff/86400);
                $rest = $diff-($days*86400);
                $hours = int($rest/3600);
                $rest = $rest-($hours*3600);
                $minutes = int($rest/60);
                $rest = $rest-($minutes*60);
                $seconds = $rest;
                if ($diff > 64800) {
                        print "CRITICAL - Mirror is $days days, $hours hours, $minutes minutes and $seconds seconds behind";
                        exit $ERRORS{"CRITICAL"};
                } else {
                        print "OK - Mirror is up to date";
                        exit $ERRORS{"OK"};
                }
        }
} else {
    print "CRITICAL - Mirror is unavailable";
    exit $ERRORS{"CRITICAL"};
}