Posting to facebook groups all at once using ruby

i create a script everyday and i post this script to twitter, facebook profile and groups so i'm trying to automate this process with some scripts, and this is my first script to post to certain facebook groups

#!/usr/bin/env ruby
require 'koala' # gem install koala --no-ri --no-rdoc

# create a facebook app and get access token from here
# https://developers.facebook.com/tools/explorer
# select "groups", "photos" when authenticating
oauth_access_token = 'xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx'
group_filtering_words = ['ruby']
image_path = 'image.png' #change to your image path
message = 'My Cool image.' # your message

graph = Koala::Facebook::API.new(oauth_access_token)

# getting groups of interest
groups = graph.get_connections("me", "groups").select do |group|
    group_filtering_words.any? do |word|
        group["name"].downcase.include? word
    end
end

index = 0
groups.each do |group|
    index += 1
    puts "[#{index}/#{groups.size}] Posting to group #{group["name"]}."
    graph.put_picture(
        image_path, 
        {:message => message}, 
        group['id']
    )
end