File upload to AWS S3 with ruby and sinatra

aws-s3.rb

require 'sinatra'
require 'aws/s3'

AWS::S3::Base.establish_connection!(
    :access_key_id => 'key_id',
    :secret_access_key => 'secret_access_key' 
)

get '/upload' do
    print 'Ez van a bucketekben:'
    print AWS::S3::Service.buckets
    erb :upload
end

# Handle POST-request (Receive and save the uploaded file)
post '/upload' do      
    bucket = AWS::S3::Bucket.find('mybucket')
    file = params['myfile'][:tempfile]
    AWS::S3::S3Object.store(file, open(file), bucket)
    puts AWS::S3::Bucket.objects('mybucket').size
end