#!/bin/sh

: << =cut

=head1 NAME

fresh-backups - Plugin to monitor the freshness of backup files

=head1 APPLICABLE SYSTEMS

Any system with some automated backup creating or updating archive files.

This works well with backup-manager.

=head1 CONFIGURATION

The following example checks all tar.bz2 files in /path/to/your/backups/, and
counts all those that are less than 2 days old, and there should be 4 separate
daily archives.

	[fresh-backups]
	user root
	env.backup_dir /path/to/your/backups/
	env.lifetime 2
	env.archive_pattern *.tar.bz2
	env.backup_number 4
	
This will also set the warning and critical values for this plugin to 2*4 and
4, respectively, meaning that if the number of fresh files goes below those
limits, the relevant notifications will be triggerred.

An example configuration snippet for backup-manager [0] follows.

	export BM_REPOSITORY_ROOT="/path/to/your/backups"
	export BM_TARBALL_FILETYPE="tar.bz2"
	export BM_TARBALL_DIRECTORIES="/etc /home /srv /data"

[0] https://github.com/sukria/Backup-Manager

=head1 AUTHOR

Olivier Mehani <shtrom+munin@ssji.net>

=head1 LICENSE

GPLv2

=head1 MAGIC MARKERS

 #%# family=manual

=cut

# Configuration directives, edit before first use.
BACKUP_DIR=${backup_dir:-/data/backup}
ARCHIVE_PATTERN="${archive_pattern:-*.tar.bz2}"
# How old backups should be considered as non-yound anymore in [days].
LIFETIME=${lifetime:-2}
# Critical states will be issued when the number of fresh backups archives is below `backup_number`,
# and warnings below `backup_number*lifetime`
CRIT=${backup_number:-1}
WARN=$((CRIT*LIFETIME))

# The situation is critical if there are no young files, the backup is down.
case $1 in
   config)
        cat << EOF
graph_title Fresh (<=${LIFETIME}d) backups archives in ${BACKUP_DIR}
graph_vlabel number
graph_args -l 0
graph_category backup
freshcount.label number
freshcount.critical ${CRIT}:
freshcount.warning ${WARN}:
EOF
        exit 0;;
esac

printf "freshcount.value "
find "${BACKUP_DIR}" -name "${ARCHIVE_PATTERN}" -a -mtime "-${LIFETIME}" | wc  -l
printf "freshcount.extinfo "
du -sh "${BACKUP_DIR}"