Move declaration of primary IPs into kubernetes-module

main.tf

@@ -4,42 +4,22 @@ resource "hcloud_ssh_key" "this" {
   public_key = each.value
 }
 
-resource "hcloud_primary_ip" "k8s_ipv4" {
-  count = var.k8s_server_count < 1 ? 1 : var.k8s_server_count
-
-  name          = "k8s_primary_ipv4_${count.index}"
-  datacenter    = var.k8s_ip_datacenter
-  type          = "ipv4"
-  assignee_type = "server"
-  auto_delete   = !var.k8s_test_installation
-}
-
-resource "hcloud_primary_ip" "k8s_ipv6" {
-  count = var.k8s_server_count < 1 ? 1 : var.k8s_server_count
-
-  name          = "k8s_primary_ipv6_${count.index}"
-  datacenter    = var.k8s_ip_datacenter
-  type          = "ipv6"
-  assignee_type = "server"
-  auto_delete   = !var.k8s_test_installation
-}
-
 module "k8s" {
   source = "./modules/hetzner/kubernetes"
 
   name     = "cluster1"
   ssh_keys = [for o in hcloud_ssh_key.this : o.id]
   servers = [for n in range(var.k8s_server_count) : {
-    ipv4_id  = hcloud_primary_ip.k8s_ipv4[n].id
-    ipv6_id  = hcloud_primary_ip.k8s_ipv6[n].id
     type          = var.k8s_server_type
     location      = var.k8s_location
+    ip_datacenter = var.k8s_ip_datacenter
   }]
   agents = [{
     type     = var.k8s_agent_type
     location = var.k8s_location
     count    = var.k8s_agent_count
   }]
+  auto_delete_primary_ips = false
   kubernetes_exposed_ips  = var.kubernetes_allowed_ips
   ssh_exposed_ips         = var.ssh_allowed_ips
   ssh_port                = 1022
@@ -66,12 +46,12 @@ locals {
       zone_ttl = values.zone_ttl
       records = toset(concat(
         values.default_A ? [
-          { name = "@", type = "A", value = hcloud_primary_ip.k8s_ipv4[0].ip_address },
+          { name = "@", type = "A", value = module.k8s.server_ips_v4[0] },
-          { name = "*", type = "A", value = hcloud_primary_ip.k8s_ipv4[0].ip_address },
+          { name = "*", type = "A", value = module.k8s.server_ips_v4[0] },
         ] : [],
         values.default_AAAA ? [
-          { name = "@", type = "AAAA", value = "${hcloud_primary_ip.k8s_ipv6[0].ip_address}1" },
+          { name = "@", type = "AAAA", value = module.k8s.server_ips_v6[0] },
-          { name = "*", type = "AAAA", value = "${hcloud_primary_ip.k8s_ipv6[0].ip_address}1" },
+          { name = "*", type = "AAAA", value = module.k8s.server_ips_v6[0] },
         ] : [],
         tolist(values.custom_records)
       ))

modules/hetzner/kubernetes/main.tf

@@ -1,3 +1,23 @@
+resource "hcloud_primary_ip" "ipv4" {
+  count = length(var.servers)
+
+  name          = "k8s_primary_ipv4_${count.index}"
+  datacenter    = var.servers[count.index].ip_datacenter
+  type          = "ipv4"
+  assignee_type = "server"
+  auto_delete   = var.auto_delete_primary_ips
+}
+
+resource "hcloud_primary_ip" "ipv6" {
+  count = length(var.servers)
+
+  name          = "k8s_primary_ipv6_${count.index}"
+  datacenter    = var.servers[count.index].ip_datacenter
+  type          = "ipv6"
+  assignee_type = "server"
+  auto_delete   = var.auto_delete_primary_ips
+}
+
 locals {
   network           = "10.0.0.0/16"
   subnet_eu_central = "10.0.0.0/24"
@@ -5,6 +25,8 @@ locals {
     for idx, config in var.servers : "${var.name}-server-${idx + 1}" => merge(
       config,
       {
+        ipv4_id  = hcloud_primary_ip.ipv4[idx].id
+        ipv6_id  = hcloud_primary_ip.ipv6[idx].id
         ip       = cidrhost(local.subnet_eu_central, idx + 2)
         first_ip = idx == 0 ? "" : cidrhost(local.subnet_eu_central, 2)
       }

modules/hetzner/kubernetes/variables.tf

@@ -8,10 +8,9 @@ variable "ssh_keys" {
 
 variable "servers" {
   type = list(object({
-    ipv4_id  = number
-    ipv6_id  = number
     type          = string
     location      = string
+    ip_datacenter = string
   }))
 }
 
@@ -47,3 +46,14 @@ variable "ssh_port" {
   type    = number
   default = 1022
 }
+
+variable "auto_delete_primary_ips" {
+  default     = true
+  description = <<EOF
+  Set this to "false" to keep the primary IPs bound to your Hetzner-Account, even after a destroy.
+  This setting would allow for reuse of the same IPs between multiple create/destroy cycles.
+  Though, it doesn't guarantee reuse of the same IPs.
+
+  Note, that reserved IPs will create costs, even if they're not used.
+  EOF
+}

variables.tf

@@ -20,15 +20,6 @@ variable "ssh_keys" {
   type = map(string)
 }
 
-variable "k8s_test_installation" {
-  default     = false
-  description = <<EOF
-  When this is set to true we configure primary-ips to not be deleted automatically!
-  This allows us to reuse the same IP for multiple create/destroy cycles.
-  As soon as the test-phase is over this should be false.
-  EOF
-}
-
 # Right now this only supports 1 location, but that's okay for me!
 variable "k8s_location" {
   type        = string