Nagios check rsnapshot

check_rsnapshot.rb

#!/usr/bin/env ruby
#
# Nagios check for rsnapshot activity and errors
# Author: James Badger <jamesbadger@gmail.com>
#
# == Documentation
#
# This script will check rsnapshot's log file to determine if it is actively
# running and that it is running without errors.
#
# Will return a critical error if:
# * The rsnapshot log file doesn't exist
# * The rsnapshot log file hasn't been updated in over CRIT_TIME seconds
# * The rsnapshot log file has reported an error since the last run began
#
# Will return a warning error if:
# * The rsnapshot log file hasn't been updated in over WARN_TIME seconds, but
#   less than CRIT_TIME seconds
# * The rsnapshot log file could not be opened for reading
#
# Else, it will return an OK message.
#
# === Assumptions
#
# Assumes rsnapshot log_file has been setup. Assumes you are running rsnapshot
# every 4 hours (for hourly snapshots). Assumes rsnapshot log location. Assumes
# rsnapshot log file format will use "rsnapshot [interval]: started" to mark
# when a rsnapshot run was initiated, and will use "ERROR" when it encounters
# a fatal error.
#
# Copyright 2011, GeoSensor Web Lab
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#

require 'time'
require 'date'

EXIT_OK = 0
EXIT_WARNING = 1
EXIT_CRITICAL = 2
EXIT_UNKNOWN = 3

LOG_FILE = "/var/log/rsnapshot/rsnapshot"

CRIT_TIME = 6 * 3600
WARN_TIME = 4 * 3600

# Check rsnapshot log existence

unless File.exist?(LOG_FILE)
    puts "RSNAPSHOT CRITICAL: Log file not found"
  exit(EXIT_CRITICAL)
end

# Check rsnapshot log activity

mtime = File.mtime(LOG_FILE)

if mtime < Time.now - CRIT_TIME
    puts "RSNAPSHOT CRITICAL: Log file not touched in > 6 hours"
  exit(EXIT_CRITICAL)
elsif mtime < Time.now - WARN_TIME
    puts "RSNAPSHOT WARNING: Log file not touched in > 4 hours"
  exit(EXIT_WARNING)
end

# Check rsnapshot log errors

if File.readable?(LOG_FILE)
    log = IO.read(LOG_FILE).split("\n").reverse
    last_run_line = log.find_index { |l| l =~ /rsnapshot ([^)]+): started/ }
    last_error_line = log.find_index { |l| l =~ /ERROR/ }
    if last_error_line && (last_error_line < last_run_line)
        puts "RSNAPSHOT CRITICAL: Last run had errors"
        exit(EXIT_CRITICAL)
    end
else
	puts "RSNAPSHOT WARNING: Log file is unreadable"
	exit(EXIT_WARNING)
end

puts "RSNAPSHOT OK"