🏭️ Refactor prepare-tf

- fix tags so that they don't contain '='
- install metrics-server only if necessary
- set a maximum size to GKE node pool
- change tags to be shorter

prepare-tf/locals.tf

@@ -1,5 +1,6 @@
 resource "random_string" "_" {
-  length  = 5
+  length  = 4
+  number  = false
   special = false
   upper   = false
 }
@@ -7,10 +8,12 @@ resource "random_string" "_" {
 resource "time_static" "_" {}
 
 locals {
-  tag = format("tf-%s-%s", formatdate("YYYY-MM-DD-hh-mm", time_static._.rfc3339), random_string._.result)
+  timestamp = formatdate("YYYY-MM-DD-hh-mm", time_static._.rfc3339)
+  tag = random_string._.result
   # Common tags to be assigned to all resources
   common_tags = [
-    "created-by=terraform",
-    "tag=${local.tag}"
+    "created-by-terraform",
+    format("created-at-%s", local.timestamp),
+    format("created-for-%s", local.tag)
   ]
 }

prepare-tf/main.tf

@@ -1,5 +1,5 @@
 module "clusters" {
-  source             = "./modules/scaleway"
+  source             = "./modules/linode"
   for_each           = local.clusters
   cluster_name       = each.value.cluster_name
   min_nodes_per_pool = var.min_nodes_per_pool
@@ -13,10 +13,10 @@ locals {
   clusters = {
     for i in range(101, 101 + var.how_many_clusters) :
     i => {
-      cluster_name    = format("%s-%03d", local.tag, i)
-      kubeconfig_path = format("./stage2/kubeconfig.%03d", i)
-      #dashdash_kubeconfig = format("--kubeconfig=./stage2/kubeconfig.%03d", i)
+      cluster_name     = format("%s-%03d", local.tag, i)
+      kubeconfig_path  = format("./stage2/kubeconfig.%03d", i)
       externalips_path = format("./stage2/externalips.%03d", i)
+      flags_path       = format("./stage2/flags.%03d", i)
     }
   }
 }
@@ -30,6 +30,15 @@ resource "local_file" "stage2" {
   )
 }
 
+resource "local_file" "flags" {
+  for_each        = local.clusters
+  filename        = each.value.flags_path
+  file_permission = "0600"
+  content         = <<-EOT
+    has_metrics_server: ${module.clusters[each.key].has_metrics_server}
+  EOT
+}
+
 resource "local_file" "kubeconfig" {
   for_each        = local.clusters
   filename        = each.value.kubeconfig_path

prepare-tf/modules/digitalocean/main.tf

@@ -5,7 +5,7 @@ resource "digitalocean_kubernetes_cluster" "_" {
   version = var.k8s_version
 
   node_pool {
-    name       = "dok-x86"
+    name       = "x86"
     tags       = local.common_tags
     size       = local.node_type
     auto_scale = true

prepare-tf/modules/googlecloud/main.tf

@@ -3,14 +3,18 @@ resource "google_container_cluster" "_" {
   project            = "prepare-tf"
   location           = "europe-north1-a"
   min_master_version = var.k8s_version
-  initial_node_count = var.min_nodes_per_pool
-  #max_size    = max(var.min_nodes_per_pool, var.max_nodes_per_pool)
-  #autoscaling = true
-  #autohealing = true
 
-  node_config {
-    tags         = var.common_tags
-    machine_type = local.node_type
+  node_pool {
+    name = "x86"
+    node_config {
+      tags         = var.common_tags
+      machine_type = local.node_type
+    }
+    initial_node_count = var.min_nodes_per_pool
+    autoscaling {
+      min_node_count = var.min_nodes_per_pool
+      max_node_count = max(var.min_nodes_per_pool, var.max_nodes_per_pool)
+    }
   }
 
   # This is not strictly necessary.
@@ -23,3 +27,4 @@ resource "google_container_cluster" "_" {
     }
   }
 }
+

prepare-tf/modules/googlecloud/outputs.tf

@@ -29,3 +29,7 @@ output "kubeconfig" {
 output "cluster_id" {
   value = google_container_cluster._.id
 }
+
+output "has_metrics_server" {
+  value = true
+}

prepare-tf/modules/linode/outputs.tf

@@ -5,3 +5,7 @@ output "kubeconfig" {
 output "cluster_id" {
   value = linode_lke_cluster._.id
 }
+
+output "has_metrics_server" {
+  value = false
+}

prepare-tf/modules/oraclecloud/outputs.tf

@@ -9,3 +9,7 @@ output "kubeconfig" {
 output "cluster_id" {
   value = oci_containerengine_cluster._.id
 }
+
+output "has_metrics_server" {
+  value = false
+}

prepare-tf/modules/scaleway/main.tf

@@ -8,7 +8,7 @@ resource "scaleway_k8s_cluster" "_" {
 
 resource "scaleway_k8s_pool" "_" {
   cluster_id  = scaleway_k8s_cluster._.id
-  name        = "scw-x86"
+  name        = "x86"
   tags        = var.common_tags
   node_type   = local.node_type
   size        = var.min_nodes_per_pool

prepare-tf/modules/scaleway/outputs.tf

@@ -5,3 +5,7 @@ output "kubeconfig" {
 output "cluster_id" {
   value = scaleway_k8s_cluster._.id
 }
+
+output "has_metrics_server" {
+  value = var.k8s_version >= 1.22
+}

prepare-tf/stage2.tmpl

@@ -140,9 +140,10 @@ provider "helm" {
 }
 
 resource "helm_release" "metrics_server_${index}" {
-  # Uncomment this for cluster that already install metrics-server
-  # (e.g. Scaleway Kapsule 1.22+, GKE...)
-  #count = 0
+  # Some providers pre-install metrics-server.
+  # Some don't. Let's install metrics-server,
+  # but only if it's not already installed.
+  count = yamldecode(file("./flags.${index}"))["has_metrics_server"] ? 0 : 1
   provider = helm.cluster_${index}
   repository = "https://charts.bitnami.com/bitnami"
   chart = "metrics-server"

prepare-tf/variables.tf

@@ -1,12 +1,14 @@
 variable "how_many_clusters" {
   type    = number
-  default = 2
+  default = 1
 }
 
 variable "node_size" {
   type    = string
   default = "M"
   # Can be S, M, L.
+  # We map these values to different specific instance types for each provider,
+  # but the idea is that they shoudl correspond to the following sizes:
   # S = 2 GB RAM
   # M = 4 GB RAM
   # L = 8 GB RAM
@@ -24,5 +26,5 @@ variable "max_nodes_per_pool" {
 
 variable "enable_arm_pool" {
   type    = bool
-  default = true
+  default = false
 }