terraform_issue.tf

provider "digitalocean" {
  token = "digitalocean token here"
}

resource "digitalocean_volume" "foo" {
  region = "ams3"
  name = "foo"
  size = 1
}

resource "digitalocean_droplet" "droplet1" {
  count = 1
  name = "droplet1"

  region = "ams3"
  size = "s-1vcpu-1gb"
  image = "docker"

  volume_ids = ["${digitalocean_volume.foo.id}"]
}