sensu-plugins/sensu-plugins-lvm

#! /usr/bin/env ruby
# frozen_string_literal: false

#
#   check-lv-usage
#
# DESCRIPTION:
#   Uses the chef-ruby-lvm gem to get the Data% from LVS command
#
# OUTPUT:
#   plain text
#
# PLATFORMS:
#   Linux
#
# DEPENDENCIES:
#   gem: sensu-plugin
#   gem: chef-ruby-lvm
#
# USAGE:
#  ./check-lv-usage.rb
#
# NOTES:
#
# LICENSE:
#   Copyright 2016 Zach Bintliff <zbintliff@gmail.com>
#   Released under the same terms as Sensu (the MIT license); see LICENSE
#   for details.
#

require 'sensu-plugin/check/cli'
require 'lvm'

#
# Check Data and MetaData Usage on LV of LVM
#
class CheckLVUsage < Sensu::Plugin::Check::CLI
  option :lv,
         short: '-l LogicalVolume[,LogicalVolume]',
         description: 'Name of logical volume (thinpool)',
         proc: proc { |a| a.split(',') }

  option :full_name,
         short: '-f FullLogicalVolume[,FullLogicalVolume]',
         description: 'Name of logical volume (docker/thinpool)',
         proc: proc { |a| a.split(',') }

  option :dwarn,
         short: '-w PERCENT',
         long: '--data-warn PERCENT',
         description: 'Warn if PERCENT or more of logical data volume',
         proc: proc(&:to_i),
         default: 85

  option :dcrit,
         short: '-c PERCENT',
         long: '--data-critical PERCENT',
         description: 'Critical if PERCENT or more of logical data volume',
         proc: proc(&:to_i),
         default: 95

  option :mwarn,
         short: '-W PERCENT',
         long: '--metadata-warn PERCENT',
         description: 'Warn if PERCENT or more of logical metadata volume',
         proc: proc(&:to_i),
         default: 85

  option :mcrit,
         short: '-C PERCENT',
         long: '--metadata-critical PERCENT',
         description: 'Critical if PERCENT or more of logical metadata volume',
         proc: proc(&:to_i),
         default: 95
  # Setup variables
  #
  def initialize(argv = ARGV)
    super(argv)
    @crit_lv = []
    @warn_lv = []
  end

  def logical_volumes
    @logical_volumes ||= LVM::LVM.new.logical_volumes.list
  end

  def empty_volumes_msg
    <<~HEREDOC
      An error occured getting the LVM info: got empty list of volumes.
      Check to ensure sensu has been configured with appropriate permissions.
      On linux systems it will generally need to allow executing `/sbin/lvm`
    HEREDOC
  end

  def filter_volumes(list)
    unknown empty_volumes_msg if list.empty?
    begin
      return list.select { |l| config[:lv].include?(l.name) } if config[:lv]
      return list.select { |l| config[:full_name].include?(l.full_name) } if config[:full_name]
    rescue StandardError
      unknown 'An error occured getting the LVM info'
    end
    list
  end

  def check_usage(volume)
    d_percent = volume.data_percent.to_i
    m_percent = volume.metadata_percent.to_i

    if d_percent >= config[:dcrit]
      @crit_lv << "#{volume.full_name} data volume is #{d_percent}% used"
    elsif d_percent >= config[:dwarn]
      @warn_lv << "#{volume.full_name} data volume is #{d_percent}% used"
    end

    if m_percent >= config[:mcrit]
      @crit_lv << "#{volume.full_name} metadata volume is #{m_percent}% used"
    elsif m_percent >= config[:mwarn]
      @warn_lv << "#{volume.full_name} metadata volume is #{m_percent}% used"
    end
  end

  # Generate output
  #
  def check_output
    (@crit_lv + @warn_lv).join(', ')
  end

  # Main function
  #
  def run
    volumes = filter_volumes(logical_volumes)
    volumes.each { |volume| check_usage(volume) }
    critical check_output unless @crit_lv.empty?
    warning check_output unless @warn_lv.empty?
    ok "All logical volume data usage under #{config[:dwarn]}% and metadata usage under #{config[:mwarn]}%"
  end
end