Use instance pools for node groups

control_plane.tf

@@ -32,6 +32,8 @@ module "master" {
   deploy_target_id = var.deploy_target_id
 
   bootstrap_bucket = var.bootstrap_bucket
+
+  use_instancepool = var.use_instancepools
 }
 
 resource "exoscale_domain_record" "etcd" {

infra.tf

@@ -33,4 +33,6 @@ module "infra" {
   deploy_target_id = var.deploy_target_id
 
   bootstrap_bucket = var.bootstrap_bucket
+
+  use_instancepool = var.use_instancepools
 }

modules/node-group/main.tf

@@ -17,7 +17,7 @@ locals {
   // having to work around merge() being a shallow merge in the compute
   // instance resource.
   user_data = [
-    for hostname in random_id.node_id[*].hex :
+    for hostname in(var.use_instancepool ? ["dummy"] : random_id.node_id[*].hex) :
     {
       "ignition" : {
         "version" : "3.1.0",
@@ -42,7 +42,7 @@ locals {
       "storage" : {
         // concatenate the private network config (if requested) with the
         // `/etc/hostname` override.
-        "files" : concat(
+        "files" : var.use_instancepool ? [] : concat(
           var.use_privnet ? local.privnet_config_files : [],
           // override /etc/hostname with short hostname, this works around the
           // fact that we can't set a separate `name` and `display_name` for
@@ -158,7 +158,7 @@ locals {
 }
 
 resource "random_id" "node_id" {
-  count       = var.node_count
+  count       = var.use_instancepool ? 0 : var.node_count
   prefix      = "${var.role}-"
   byte_length = 2
 }
@@ -170,7 +170,7 @@ resource "exoscale_anti_affinity_group" "anti_affinity_group" {
 }
 
 resource "exoscale_compute_instance" "nodes" {
-  count       = var.node_count
+  count       = var.use_instancepool ? 0 : var.node_count
   name        = "${random_id.node_id[count.index].hex}.${var.cluster_domain}"
   ssh_key     = var.ssh_key_pair
   zone        = var.region
@@ -207,3 +207,27 @@ resource "exoscale_compute_instance" "nodes" {
     ]
   }
 }
+
+resource "exoscale_instance_pool" "nodes" {
+  count       = var.use_instancepool ? local.anti_affinity_group_count : 0
+  name        = "${var.role}-${count.index}"
+  size        = var.node_count
+  zone        = var.region
+  key_pair    = var.ssh_key_pair
+  template_id = var.template_id
+
+  instance_prefix = var.role
+  instance_type   = var.instance_type
+
+  disk_size = local.disk_size
+  user_data = base64encode(jsonencode(local.user_data[0]))
+
+  deploy_target_id = var.deploy_target_id
+
+  security_group_ids = var.security_group_ids
+
+  anti_affinity_group_ids = concat(
+    [exoscale_anti_affinity_group.anti_affinity_group[count.index].id],
+    var.additional_affinity_group_ids
+  )
+}

modules/node-group/output.tf

@@ -1,3 +1,7 @@
+locals {
+  instance_pool_ips = var.use_instancepool ? exoscale_instance_pool.nodes[*].instances[*].public_ip_address : []
+  instance_ips      = var.use_privnet ? exoscale_compute_instance.nodes[*].network_interface[0].ip_address : exoscale_compute_instance.nodes[*].public_ip_address
+}
 output "ip_address" {
-  value = var.use_privnet ? exoscale_compute_instance.nodes[*].network_interface[0].ip_address : exoscale_compute_instance.nodes[*].public_ip_address
+  value = var.use_instancepool ? local.instance_pool_ips : local.instance_ips
 }

modules/node-group/variables.tf

@@ -126,3 +126,9 @@ variable "affinity_group_capacity" {
   default     = 0
   description = "Capacity of the affinity group, e.g. when using dedicated hypervisors, default: 0 (unlimited)"
 }
+
+variable "use_instancepool" {
+  type        = bool
+  description = "Use instancepool for this node group"
+  default     = false
+}

variables.tf

@@ -238,3 +238,9 @@ variable "additional_lb_security_group_ids" {
   default     = []
   description = "List of additional security group IDs to configure on the LBs"
 }
+
+variable "use_instancepools" {
+  type        = bool
+  description = "Use instance pools for node groups"
+  default     = true
+}

worker.tf

@@ -35,6 +35,8 @@ module "worker" {
   deploy_target_id = var.deploy_target_id
 
   bootstrap_bucket = var.bootstrap_bucket
+
+  use_instancepool = var.use_instancepools
 }
 
 // Additional worker groups.
@@ -74,7 +76,7 @@ module "additional_worker" {
     [exoscale_security_group.all_machines.id]
   )
 
-  affinity_group_capacity = var.affinity_group_capacity
+  affinity_group_capacity = 1
   additional_affinity_group_ids = concat(
     each.value.affinity_group_ids != null ? each.value.affinity_group_ids : [],
     var.additional_affinity_group_ids
@@ -83,4 +85,6 @@ module "additional_worker" {
   deploy_target_id = var.deploy_target_id
 
   bootstrap_bucket = var.bootstrap_bucket
+
+  use_instancepool = true
 }