variable "foo" { default = "bar"; description = "bar"; } provider "aws" { foo = "${openstack_floating_ip.random.value}" } resource "openstack_floating_ip" "random" {} resource "aws_security_group" "firewall" {} resource "aws_instance" "web" { ami = "${var.foo}" security_groups = [ "foo", "${aws_security_group.firewall.foo}" ] } resource "aws_load_balancer" "weblb" { members = "${aws_instance.web.id_list}" }