A nagios plugin for PostgreSQL backup tool barman

Overview

This plugin is able to do several checks:

• SSH connection to Master server
• PostgreSQL connection to Master server
• Available Backups
• Time of last received WAL file
• Failed backups
• Missing WAL files in the latest backup

Installation

This plugin is written in Ruby, so a working Ruby installation is required

$ git clone https://github.com/hamann/check-barman
$ cd check-barman
$ gem install rbarman
$ chmod +x check-barman.rb
$ ./check-barman.rb
Usage check-barman.rb [options]
    -a, --action ACTION                      The name of the check to be executed
    -s, --server SERVER                      The 'server' in barman terms
    -w, --warning WARNING                    The warning level
    -c, --critical CRITICAL                  The critical level
    -h, --barman-home PATH                   path to barman's Home directory, default /var/lib/barman
    -b, --barman-binary PATH                 path to barman binary, default /usr/bin/barman
    -m, --missing-wals-check-limit NUMBER    Check only the last n wal files (reduces execution time)

Usage

To test this script, become 'barman' user

The parameters action (-a/--action) and server (-s /--server) are required, where action can be one of

• ssh
• pg
• backups_available
• last_wal_received
• failed_backups
• missing_wals

The parameters warning and critical are required if action is backups_available, last_wal_received or failed_backups and its values depend on the action context:

• backups_available => number
• last_wal_received => seconds
• failed_backups => number

Examples:

check if SSH connection to master server is ok

$ ./check-barman.rb -a ssh -s test1
SSH connection ok

check if PostgreSQL connection to the master server is ok

$ ./check-barman.rb -a pg -s test1
PG connection ok

check number of backups and set warning if number of backups is > 5 or set critical if number of backups is > 6

$ ./check-barman.rb -a backups_available -s test1 -w 5 -c 6
"4 backups available"

check when the last WAL file was received and set warning if time difference is > 300 seconds or set critical if time difference is > 600 seconds

$ ./check-barman.rb -a last_wal_received -s test1 -w 300 -c 600
"Last wal was received 121 seconds ago (000000010000109100000014)"

check if there are failed backups

$ ./check-barman.rb -a failed_backups -s test1 -w 1 -c 2

check if all WAL files exist in the latest backup. This check is more time consuming because it has to compute the range of WAL files which have to exist since start of base backup and the last received WAL file, and check for there according entry in xlog.db (=> barman processed them). Consider to increase check_timeout or check_interval in case your backups are large! Alternatively define a limit with '-m N', which checks only the last N wal files

$ ./check-barman.rb -a missing_wals -s test1
"There are no missing wal files in the latest backup"

Configuration

Give nagios user all privileges to read backup data or executing barman by adding an entry to sudoers file like:

Defaults:nagios !requiretty
nagios ALL=NOPASSWD:/usr/lib/nagios/plugins/check-barman/check-barman.rb

and use '-h /var/lib/barman' as option to nagios or nrpe command definition, e.g for nrpe

$ cat /etc/nagios/nrpe.d/barman_commands.cfg
command[check_barman_missing_wals_test]=sudo /usr/lib/nagios/plugins/check-barman/check-barman.rb -a missing_wals