gistfile1.rb

#!/usr/bin/ruby

require 'rubygems'
require 'thor'
require 'chef'
require 'chef/node'
require 'chef/rest'

Chef::Config.from_file("/etc/chef/server.rb")

API_USERNAME='user'
API_PASSWORD='pass'

class Knife < Thor

  desc "add_recipe", "Add a recipe to a node"
  method_options :recipe => :required, :after => :optional, :node => :required
  def add_recipe
    authenticate
    node = @rest.get_rest("nodes/#{options[:node]}")
    node.recipes << options[:recipe] if !node.recipes.include?(options[:recipe])
    @rest.put_rest("nodes/#{options[:node]}", node)
    list_recipes
  end

  desc "remove_recipe", "Remove a recipe from a node"
  method_options :recipe => :required, :node => :required
  def remove_recipe
    authenticate
    node = @rest.get_rest("nodes/#{options[:node]}")
    node.recipes.delete(options[:recipe]) if node.recipes.include?(options[:recipe])
    @rest.put_rest("nodes/#{options[:node]}", node)
    list_recipes
  end

  desc "list_recipes", "List a node's recipes"
  method_options :node => :required
  def list_recipes
    authenticate
    node = @rest.get_rest("nodes/#{options[:node]}")
    puts node.recipes.inspect
  end

  def authenticate
    @rest = Chef::REST.new(Chef::Config[:registration_url])
    @rest.authenticate(API_USERNAME, API_PASSWORD)
  end
end

Knife.start