Using Ohai to get aws creds using IAM instance role

instance_creds.rb

require 'ohai'
o = Ohai::System.new
o.all_plugins

access_key_id = o[:ec2][:iam]["security-credentials"].first[1]["AccessKeyId"]
secret_access_key = o[:ec2][:iam]["security-credentials"].first[1]["SecretAccessKey"]
token = o[:ec2][:iam]["security-credentials"].first[1]["Token"]

require 'right_aws'

class RightAws::S3Interface < RightAws::RightAwsBase
  alias_method :orig_generate_rest_request, :generate_rest_request
  def generate_rest_request(method, headers)
    headers = {"x-amz-security-token" => @params[:token]}.merge(headers) if @params[:token]
    orig_generate_rest_request(method, headers)
  end
end

s3 = RightAws::S3.new(access_key_id, secret_access_key, token: token)