[CI] Misc fixes

This makes a couple misc fixes needed for setting up the new cluster:
* Added a node locations option for the service nodes so that they do not
  get replicated per zone in regional clusters.
* Make the k8s secrets for the runner scale sets depend on the namespace
  resources so that we do not end up in an error caused by a race condition
  where TF tries to create the secrets in a nonexistent namespace.

This is not actually enough to get the second cluster running. Trying to
startup ARC causes failures as we are currently not specifying a runner
group and the runner scale sets need to be placed under different runner
groups.

Author: boomanaiden154

premerge/gke_cluster/main.tf

@@ -15,10 +15,11 @@ resource "google_container_cluster" "llvm_premerge" {
 }
 
 resource "google_container_node_pool" "llvm_premerge_linux_service" {
-  name       = "llvm-premerge-linux-service"
-  location   = var.region
-  cluster    = google_container_cluster.llvm_premerge.name
-  node_count = 3
+  name           = "llvm-premerge-linux-service"
+  location       = var.region
+  cluster        = google_container_cluster.llvm_premerge.name
+  node_count     = 3
+  node_locations = var.service_node_pool_locations
 
   node_config {
     machine_type = "e2-highcpu-4"

premerge/gke_cluster/variables.tf

@@ -16,4 +16,10 @@ variable "linux_machine_type" {
 variable "windows_machine_type" {
   description = "The type of machine to use for Windows instances"
   type        = string
-}
+}
+
+variable "service_node_pool_locations" {
+  description = "The location to run the service node pool in"
+  type        = list(any)
+  default     = null
+}

premerge/main.tf

@@ -61,12 +61,17 @@ moved {
   to   = module.premerge_cluster_us_central
 }
 
+# We explicitly specify a single zone for the service node pool locations as
+# terraform by default will create node_count nodes per zone. We only want
+# node_count nodes rather than (node_count * zone count) nodes, so we
+# explicitly enumerate a specific region.
 module "premerge_cluster_us_west" {
-  source               = "./gke_cluster"
-  cluster_name         = "llvm-premerge-cluster-us-west"
-  region               = "us-west8"
-  linux_machine_type   = "n2d-standard-64"
-  windows_machine_type = "n2d-standard-32"
+  source                      = "./gke_cluster"
+  cluster_name                = "llvm-premerge-cluster-us-west"
+  region                      = "us-west1"
+  linux_machine_type          = "n2d-standard-64"
+  windows_machine_type        = "n2d-standard-32"
+  service_node_pool_locations = ["us-west1-a"]
 }
 
 provider "helm" {

premerge/premerge_resources/main.tf

@@ -36,6 +36,8 @@ resource "kubernetes_secret" "linux_github_pat" {
   }
 
   type = "Opaque"
+
+  depends_on = [kubernetes_namespace.llvm_premerge_linux_runners]
 }
 
 resource "kubernetes_namespace" "llvm_premerge_windows_runners" {
@@ -57,6 +59,8 @@ resource "kubernetes_secret" "windows_github_pat" {
   }
 
   type = "Opaque"
+
+  depends_on = [kubernetes_namespace.llvm_premerge_windows_runners]
 }
 
 resource "helm_release" "github_actions_runner_controller" {