# File lib/deltacloud/drivers/ec2/ec2_driver.rb, line 689
        def delete_firewall_rule(credentials, opts={})
          ec2 = new_client(credentials)
          firewall = opts[:firewall]
          protocol, from_port, to_port, addresses, groups = firewall_rule_params(opts[:rule_id])
          safely do
            ec2.manage_security_group_ingress(firewall, from_port, to_port, protocol, "revoke", addresses, groups)
          end
        end