Nagios Check Plugin for Rsnapshot Backups

In a previous post, I described how I do Secure rsnapshot backups over the WAN via SSH. While my layout of rsnapshot configuration files, data, and log files is a bit esoteric, I monitor all this with a Nagios check plugin that runs on my backup host. It Assumes that the output of rsnapshot is written to a text log file, one file per host, at a path that matches /path_to_log_directory/log_HOSTNAME_YYYYMMDD-HHMMSS.log where HOSTNAME is the name of the host, and YYYYMMDD-HHMMSS is a datestamp (actually, the script just finds the newest file matching log_HOSTNAME_*.log in that directory). In order to obtain correct timing of the runs, which rsnapshot doesn’t offer, it assumes that you trigger rsnapshot through a wrapper script, which runs it once per host (inside a loop?) with per-host log files and some logging information added, like:

for h in 
do
    LOGFILE="/mnt/backup/rsnapshot/logs/log_${h}_`date +%Y%m%d-%H%M%S`.txt"
    echo "# Starting backup at `date` (`date +%s`)" >> "$LOGFILE"
    /usr/bin/rsnapshot -c /etc/rsnapshot-$h.conf daily &>> "$LOGFILE"
    echo "# Finished backup at `date` (`date +%s`)" >> "$LOGFILE"
done

The check_rsnapshot.pl plugin uses utils.pm from Nagios, as well as Getopt::Long, File::stat, File::Basename, File::Spec and Number::Bytes::Human. This was one of my first Perl plugins, but seems to be rather acceptable. It makes the following checks based on the rsnapshot log:

1. Backup run in the last X seconds (warning and crit thresholds)
2. Maximum time from start to finish (warning and crit thresholds)
3. Minimum size of backup (warning and crit thresholds)
4. Minimum number of files in backup (warning and crit thresholds)

In addition to check_file_age checks on a number of files that are included in backups and I know are modified before each backup run, this seems to handle monitoring quite well for me. I certainly preferred running Bacula and using my MySQL-based check_bacula_job.php, but as I’m now backing up 4 machines to my desktop, I no longer have a need for Bacula (or tapes).

The script itself can be found at github.