From e9a4b1c5c68012a99ac6d2b85c581b55bbace3a4 Mon Sep 17 00:00:00 2001
From: Stephan Feurer <stephan.feurer@vshn.net>
Date: Fri, 13 Sep 2024 14:29:51 +0200
Subject: [PATCH] Support creating multiple affinit groups

A new variable affinity_group_capacity defines the capacity of an affinity group.
---
 control_plane.tf                | 1 +
 infra.tf                        | 1 +
 modules/node-group/main.tf      | 9 ++++++---
 modules/node-group/variables.tf | 6 ++++++
 storage.tf                      | 1 +
 variables.tf                    | 6 ++++++
 worker.tf                       | 2 ++
 7 files changed, 23 insertions(+), 3 deletions(-)

diff --git a/control_plane.tf b/control_plane.tf
index ae4f210..a9837b0 100644
--- a/control_plane.tf
+++ b/control_plane.tf
@@ -26,6 +26,7 @@ module "master" {
     exoscale_security_group.control_plane.id,
   ]
 
+  affinity_group_capacity       = var.affinity_group_capacity
   additional_affinity_group_ids = var.additional_affinity_group_ids
 
   deploy_target_id = var.deploy_target_id
diff --git a/infra.tf b/infra.tf
index 656098d..17df122 100644
--- a/infra.tf
+++ b/infra.tf
@@ -27,6 +27,7 @@ module "infra" {
     exoscale_security_group.infra.id,
   ]
 
+  affinity_group_capacity       = var.affinity_group_capacity
   additional_affinity_group_ids = var.additional_affinity_group_ids
 
   deploy_target_id = var.deploy_target_id
diff --git a/modules/node-group/main.tf b/modules/node-group/main.tf
index ff5f7bc..bf897c4 100644
--- a/modules/node-group/main.tf
+++ b/modules/node-group/main.tf
@@ -1,6 +1,9 @@
 locals {
   disk_size = var.root_disk_size + var.data_disk_size + var.storage_disk_size
 
+  anti_affinity_group_capacity = var.affinity_group_capacity > 0 ? var.affinity_group_capacity : 999999
+  anti_affinity_group_count    = var.affinity_group_capacity > 0 ? ceil(var.node_count / var.affinity_group_capacity) : 1
+
   ignition_source = {
     "bootstrap" = "${trimsuffix(var.bootstrap_bucket, "/")}/bootstrap.ign"
     "master"    = "https://${var.api_int}:22623/config/master"
@@ -161,8 +164,8 @@ resource "random_id" "node_id" {
 }
 
 resource "exoscale_anti_affinity_group" "anti_affinity_group" {
-  count       = var.node_count > 0 ? 1 : 0
-  name        = "${var.cluster_id}_${var.role}"
+  count       = var.node_count != 0 ? local.anti_affinity_group_count : 0
+  name        = "${var.cluster_id}_${var.role}_${count.index}"
   description = "${var.cluster_id} ${var.role} nodes"
 }
 
@@ -181,7 +184,7 @@ resource "exoscale_compute_instance" "nodes" {
 
   security_group_ids = var.security_group_ids
   anti_affinity_group_ids = concat(
-    [exoscale_anti_affinity_group.anti_affinity_group[0].id],
+    [exoscale_anti_affinity_group.anti_affinity_group[floor(count.index / local.anti_affinity_group_capacity)].id],
     var.additional_affinity_group_ids
   )
 
diff --git a/modules/node-group/variables.tf b/modules/node-group/variables.tf
index 041a9ec..d87695b 100644
--- a/modules/node-group/variables.tf
+++ b/modules/node-group/variables.tf
@@ -120,3 +120,9 @@ variable "deploy_target_id" {
   default     = ""
   description = "ID of special deployment target, e.g. dedicated hypervisors"
 }
+
+variable "affinity_group_capacity" {
+  type        = number
+  default     = 0
+  description = "Capacity of the affinity group, e.g. when using dedicated hypervisors, default: 0 (unlimited)"
+}
diff --git a/storage.tf b/storage.tf
index e13c4ba..30aadf9 100644
--- a/storage.tf
+++ b/storage.tf
@@ -31,6 +31,7 @@ module "storage" {
     exoscale_security_group.storage.id,
   ]
 
+  affinity_group_capacity       = var.affinity_group_capacity
   additional_affinity_group_ids = var.additional_affinity_group_ids
 
   deploy_target_id = var.deploy_target_id
diff --git a/variables.tf b/variables.tf
index 241be83..a436ec8 100644
--- a/variables.tf
+++ b/variables.tf
@@ -193,6 +193,12 @@ variable "deploy_target_id" {
   description = "ID of special deployment target, e.g. dedicated hypervisors"
 }
 
+variable "affinity_group_capacity" {
+  type        = number
+  default     = 0
+  description = "Capacity of the affinity group, e.g. when using dedicated hypervisors, default: 0 (unlimited)"
+}
+
 variable "ignition_ca" {
   type = string
 }
diff --git a/worker.tf b/worker.tf
index 9dc1c98..11d1bcc 100644
--- a/worker.tf
+++ b/worker.tf
@@ -29,6 +29,7 @@ module "worker" {
     [exoscale_security_group.all_machines.id]
   )
 
+  affinity_group_capacity       = var.affinity_group_capacity
   additional_affinity_group_ids = var.additional_affinity_group_ids
 
   deploy_target_id = var.deploy_target_id
@@ -73,6 +74,7 @@ module "additional_worker" {
     [exoscale_security_group.all_machines.id]
   )
 
+  affinity_group_capacity = var.affinity_group_capacity
   additional_affinity_group_ids = concat(
     each.value.affinity_group_ids != null ? each.value.affinity_group_ids : [],
     var.additional_affinity_group_ids