Mongodb collection copier using moped gem

MongoCopier.rb

require 'rubygems'
require 'moped'

class MongoCopier

  attr_accessor :source_addr, :dest_addr, :db_name
  attr_reader   :source_session, :dest_session

  def initialize(db_name, addrs = {})
    @source_addr = addrs[:source] || 'localhost:27017'
    @dest_addr   = addrs[:dest]   || 'localhost:27017'
    @db_name     = db_name
  end

  def session(db_name, addr = 'localhost:27017')
    s = Moped::Session.new([addr])
    s.use db_name
    s.with(safe: { w: 2, wtimeout: 10 })
    return s
  end

  def copy_collection(colletion, query = {})
    source = self.session(db_name, source_addr)
    dest   = self.session(db_name, dest_addr)

    source[colletion].find(query).each do |record|
      dest[colletion].insert(record)
    end
  end

end

#Examples

copier = MongoCopier.new(:test, {source: "192.168.1.100:27017", dest: 'localhost:27017'})

#copy full collection
copier.copy_collection(:products)

#copy selected record from the collection by passing query
copier.copy_collection(:products, {:name => 'iphone5'})
copier.copy_collection(:products, {:categories => { '$in' => ['mobile', 'book']}})