check-cmd.rb

#! /usr/bin/env ruby
#
# check-cmd
#
# DESCRIPTION:
#   Generic check raising an error if exit code of command is not N.
#
# OUTPUT:
#   plain text
#
# PLATFORMS:
#   Linux
#
# DEPENDENCIES:
#   gem: sensu-plugin
#   gem: english
#
# USAGE:
#
# NOTES:
#
# LICENSE:
#   Jean-Francois Theroux <failshell@gmail.com>
#   Released under the same terms as Sensu (the MIT license); see LICENSE
#   for details.
#

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

#
# Check Command Status
#
class CheckCmdStatus < Sensu::Plugin::Check::CLI
  option :command,
         description: 'command to run (might need quotes)',
         short: '-c',
         long: '--command COMMAND',
         required: true

  option :status,
         description: 'exit status code the check should get',
         short: '-s',
         long: '--status STATUS',
         default: '0'

  option :check_output,
         description: 'Optionally check the process stdout against a regex',
         short: '-o',
         long: '--check_output REGEX'

  option :echo_stdout,
         description: 'Output the stdout of the command',
         short: '-e',
         long: '--echo_stdout',
         boolean: true,
         default: false

  # Acquire the exit code and/or output of a command and alert if it is not
  # what is expected.
  #
  def acquire_cmd_status
    stdout = `#{config[:command]}`
    # #YELLOW
    if $CHILD_STATUS.exitstatus.to_s == config[:status]
      check_cmd_output(stdout)
    else
      status = "#{config[:command]} exited with #{$CHILD_STATUS.exitstatus}"
      status += "\nOutput: #{stdout}" if config[:echo_stdout]
      critical status
    end
  end

  def check_cmd_output(stdout)
    if config[:check_output]
      if Regexp.new(config[:check_output]).match(stdout)
        status = "#{config[:command]} matched #{config[:check_output]} and exited with #{$CHILD_STATUS.exitstatus}"
        status += "\nOutput: #{stdout}" if config[:echo_stdout]
        ok status
      else
        status = "#{config[:command]} output didn't match #{config[:check_output]} (exit #{$CHILD_STATUS.exitstatus})"
        status += "\nOutput: #{stdout}" if config[:echo_stdout]
        critical status
      end
    else
      status = "#{config[:command]} exited with #{$CHILD_STATUS.exitstatus}"
      status += "\nOutput: #{stdout}" if config[:echo_stdout]
      ok status
    end
  end

  # main function
  #
  def run
    acquire_cmd_status
  end
end