I'm learning about creating a k8s cluster on DO using terraform, I've been trying to take the ID of the single K8s node I've created, and reference it from the loadbalancer.

The main reasoning for this is so that I can declare the FQDN in the .tf file.

First, here is the cluster declaration:

variable "digitalocean_token" {}

provider "digitalocean" {
  token = "${var.digitalocean_token}"
}

resource "digitalocean_kubernetes_cluster" "foo" {
  name    = "foo"
  region  = "nyc1"
  version = "1.12.1-do.2"

  node_pool {
    name       = "woker-pool"
    size       = "s-1vcpu-2gb"
    node_count = 1
  }
}

And here is the load balancer declaration:

resource "digitalocean_loadbalancer" "foo" {
  name = "k8s-lb.nyc1"
  region = "nyc1"

  forwarding_rule {
    entry_port = 80
    entry_protocol = "http"

    target_port     = 80
    target_protocol = "http"
  }
  droplet_ids = ["${digitalocean_kubernetes_cluster.foo.node_pool.0.id}"]
}

output "loadbalancer_ip" {
  value = "${digitalocean_loadbalancer.foo.ip}"
}

resource "digitalocean_record" "terraform" {
  domain = "example.com" # "${digitalocean_domain.example.name}"
  type   = "A"
  name   = "terraform"
  value  =  "${digitalocean_loadbalancer.foo.ip}"
}

# Output the FQDN for the record
output "fqdn" {
  value = "${digitalocean_record.terraform.fqdn}"
}

I'm guessing that maybe the digitalocean_loadbalancer resources is only setup to work with individual droplets?

Here are the output errors: when I run terraform apply:

* output.loadbalancer_ip: Resource 'digitalocean_loadbalancer.foo' not found for variable 'digitalocean_loadbalancer.foo.ip'

* digitalocean_record.terraform: Resource 'digitalocean_loadbalancer.foo' not found for variable 'digitalocean_loadbalancer.foo.ip'

* digitalocean_loadbalancer.foo: droplet_ids.0: cannot parse '' as int: strconv.ParseInt: parsing "d4292e64-9c0a-4afb-83fc-83f239bcb4af": invalid syntax

Pt. 2

I added a digitalocean_droplet resource, to see what kind of id was passed to the load balancer.

resource "digitalocean_droplet" "web" {
  name      = "web-1"
  size      = "s-1vcpu-1gb"
  image     = "ubuntu-18-04-x64"
  region    = "nyc1"
}

digitalocean_kubernetes_cluster.foo.node_pool.0.id = '6ae6a787-d837-4e78-a915-cb52155f66fe'

digitalocean_droplet.web.id = 132533158