facts-mc-agent.rb

#!/usr/bin/env ruby

# MC Agent for facts.txt
#
# This is my test at pushing/popping/querying data from facts.txt
#
# Initial file contains:
#
# huron_class=staff,shel
# environment=production

hash = {}
searchvar = "shel"
pushvar = "crankd"

def open_file()
  h = {}
  
  # Open /etc/facts.txt if it exists, fail if it does not.
  if File.exists?("/etc/facts.txt")
    File.open("/etc/facts.txt") do |fp|
      fp.each do |line|
        key, value = line.chomp.split("=")
        h[key] = value
      end
    end
    return h
  else
    puts "File does not exist"
    exit(1)
  end
end # End of open_file def

if ARGV[0] == "-r"
  hash = open_file()

  if hash.size == 0
    puts "/etc/facts.txt contains no key/value pairs"
    exit(0)
  end
  
  puts "Before Removing Variable:\n"
  hash.each {|key, value| puts "#{key} is #{value}"}

  # Attempt at removing a searched class from the list of classes
  # This is only proof-of-concept, no file writes yet
  if hash["huron_class"] =~ /,#{searchvar},/ or hash["huron_class"] =~ /,#{searchvar}/
    hash["huron_class"][",#{searchvar}"]= ""
  elsif hash["huron_class"] =~ /#{searchvar},/
    hash["huron_class"]["#{searchvar},"]= ""
  elsif hash["huron_class"] == "#{searchvar}"
    hash["huron_class"] = ""
  else
    puts "\nSearch Variable does not exist."
  end

  puts "\nAfter Removing Variable:\n"
  hash.each {|key, value| puts "#{key} is #{value}"}
end

if ARGV[0] == "-a"
  hash = open_file()

  if hash.size == 0
    puts "/etc/facts.txt contains no key/value pairs"
    exit(0)
  end
  
  # Attempt at Adding a passed variable onto the list of classes
  # This is only proof-of-concept, no file writes yet
  puts "\nBefore Adding Variable to List:\n"
  hash.each {|key, value| puts "#{key} is #{value}"}

  hash["huron_class"] += ",#{pushvar}"

  puts "\nAfter Adding Variable:\n"
  hash.each {|key, value| puts "#{key} is #{value}"}
end