incus_instance argument wait_for_network shouldn't assume IPv4

[vegardx]

Currently the wait_for_network argument when set to true will wait for the instance to have an IPv4 address. This means that you can only use this argument reliably in networks where IPv4 is available, which makes it a little harder to do things like updating DNS records with the output of an instance creation on IPv6-only networks, or where IPv6 is the network you're actually relying on.

Example code:

resource "incus_instance" "this" {
  count = 10

  type                     = "container"
  name                     = "instance-${count.index}"
  image                    = "images:debian/12/cloud"
  wait_for_network         = true

  config = {
    "boot.autostart" = true
  }
}

output "instance_ips" {
  value = { for idx, instance in incus_instance.this : instance.name => instance.ipv6_address }
}

Expected results:

instance_ip = {
  "instance-0" = "..."
...
}

Actual results:

incus_instance.this[8]: Creating...
incus_instance.this[4]: Creating...
incus_instance.this[5]: Creating...
incus_instance.this[6]: Creating...
incus_instance.this[2]: Creating...
incus_instance.this[7]: Creating...
incus_instance.this[9]: Creating...
incus_instance.this[3]: Creating...
incus_instance.this[1]: Creating...
incus_instance.this[4]: Still creating... [10s elapsed]
...
incus_instance.this[6]: Still creating... [3m10s elapsed]
╷
│ Error: Failed to wait for instance "instance-4" to get an IP address
│
│   with incus_instance.this[4],
│   on main.tf line 74, in resource "incus_instance" "this":
│   74: resource "incus_instance" "this" {
│
│ timeout while waiting for state to become 'OK' (last state: 'Waiting for network',
│ timeout: 3m0s)
╵
╷
│ Error: Failed to wait for instance "instance-9" to get an IP address
│
│   with incus_instance.this[9],
│   on main.tf line 74, in resource "incus_instance" "this":
│   74: resource "incus_instance" "this" {
│
│ timeout while waiting for state to become 'OK' (last state: 'Waiting for network',
│ timeout: 3m0s)
╵
╷
│ Error: Failed to wait for instance "instance-1" to get an IP address
│
│   with incus_instance.this[1],
│   on main.tf line 74, in resource "incus_instance" "this":
│   74: resource "incus_instance" "this" {
│
│ timeout while waiting for state to become 'OK' (last state: 'Waiting for network',
│ timeout: 3m0s)
╵
╷
│ Error: Failed to wait for instance "instance-6" to get an IP address
│
│   with incus_instance.this[6],
│   on main.tf line 74, in resource "incus_instance" "this":
│   74: resource "incus_instance" "this" {
│
│ timeout while waiting for state to become 'OK' (last state: 'Waiting for network',
│ timeout: 3m0s)
╵
╷
│ Error: Failed to wait for instance "instance-2" to get an IP address
│
│   with incus_instance.this[2],
│   on main.tf line 74, in resource "incus_instance" "this":
│   74: resource "incus_instance" "this" {
│
│ timeout while waiting for state to become 'OK' (last state: 'Waiting for network',
│ timeout: 3m0s)
╵
╷
│ Error: Failed to wait for instance "instance-3" to get an IP address
│
│   with incus_instance.this[3],
│   on main.tf line 74, in resource "incus_instance" "this":
│   74: resource "incus_instance" "this" {
│
│ timeout while waiting for state to become 'OK' (last state: 'Waiting for network',
│ timeout: 3m0s)
╵
╷
│ Error: Failed to wait for instance "instance-5" to get an IP address
│
│   with incus_instance.this[5],
│   on main.tf line 74, in resource "incus_instance" "this":
│   74: resource "incus_instance" "this" {
│
│ timeout while waiting for state to become 'OK' (last state: 'Waiting for network',
│ timeout: 3m0s)
╵
╷
│ Error: Failed to wait for instance "instance-8" to get an IP address
│
│   with incus_instance.this[8],
│   on main.tf line 74, in resource "incus_instance" "this":
│   74: resource "incus_instance" "this" {
│
│ timeout while waiting for state to become 'OK' (last state: 'Waiting for network',
│ timeout: 3m0s)
╵
╷
│ Error: Failed to wait for instance "instance-7" to get an IP address
│
│   with incus_instance.this[7],
│   on main.tf line 74, in resource "incus_instance" "this":
│   74: resource "incus_instance" "this" {
│
│ timeout while waiting for state to become 'OK' (last state: 'Waiting for network',
│ timeout: 3m0s)