Modification to taghosts to list available tags

taghosts

#!/usr/bin/env ruby

require 'optparse'

ACTIVE_SERVERS = '/l/local/active-servers'

def alltags
  alltags = []
  File.open(ACTIVE_SERVERS).each do |line|
    tokens = line.split(/\s+/)
    alltags += tokens.drop(1)
  end
  puts alltags.sort.uniq.join("\n")
  exit
end

# extend Array with methods to compare to other arrays
class Array
  # returns true if this array contains all the elements in other_array
  def contains_all(other_array)
    self & other_array == other_array
  end

  # returns true if this array contains any of the elements in other_array
  def contains_any(other_array)
    !(self & other_array).empty?
  end
end

def handle_alltags_option(opts)
  opts.on('-a', '--all-tags', 'show all tags') do
    alltags
  end
  
  opts.on('-l', '--list-tags', 'list available tags') do
    list_tags
    exit
  end
  
end


def list_tags
  taglist =  File.open(ACTIVE_SERVERS).map{|x| x.split(/\s+/)[1..-1]}.flatten.uniq.sort
  quartertags = taglist.size / 4
  columns = []
  columns << taglist.slice!(0..quartertags) until taglist.empty?
  puts "\nAll available tags:"
  columns.map(&:size).max.times do |i|
    puts '%-15s %-15s %-15s %-15s' % columns.map{|x| x[i]}
  end
end


def handle_prohibited_tags_option(opts, prohibited_tags)
  opts.on('-v', '--invert-match TAG', 'select hosts with tag') do |tag|
    prohibited_tags.push(tag)
  end
end

def parse_options
  prohibited_tags = []
  OptionParser.new do |opts|
    opts.banner = 'Usage: taghosts [tag1 tag2 ...] [-v notag1 notag2 ...]'
    handle_prohibited_tags_option(opts, prohibited_tags)
    handle_alltags_option(opts)
  end.parse!

  # remaining arguments are required tags
  [ARGV, prohibited_tags]
end

def servers_with_tags(required_tags, prohibited_tags)
  required_tags.sort!
  prohibited_tags.sort!
  servers = []

  File.foreach(ACTIVE_SERVERS) do |line|
    tags = line.split(/\s+/)
    host = tags.shift
    tags.sort!
    if tags.contains_all(required_tags) && !tags.contains_any(prohibited_tags)
      servers.push(host)
    end
  end

  servers
end

puts servers_with_tags(*parse_options) if __FILE__ == $PROGRAM_NAME