[CI] Add gcs_bucket_location variable to gke_cluster module

This patch introduces a new gcs_bucket_location variable. Without this we
cannot deploy the GCS buckets in the us-central1 region as the cluster is
a zonal cluster in us-central1-a. Buckets have to be regional and cannot
be specific to a zone, so we would get API errors when running
terraform apply.

Author: boomanaiden154

premerge/gke_cluster/main.tf

@@ -144,15 +144,15 @@ resource "google_container_node_pool" "llvm_premerge_windows_2022" {
 
 resource "google_storage_bucket" "object_cache_linux" {
   name     = format("%s-object-cache-linux", var.cluster_name)
-  location = var.region
+  location = var.gcs_bucket_location
 
   uniform_bucket_level_access = true
   public_access_prevention    = "enforced"
 }
 
 resource "google_storage_bucket" "object_cache_windows" {
   name     = format("%s-object-cache-windows", var.cluster_name)
-  location = var.region
+  location = var.gcs_bucket_location
 
   uniform_bucket_level_access = true
   public_access_prevention    = "enforced"

premerge/gke_cluster/variables.tf

@@ -8,6 +8,11 @@ variable "region" {
   type        = string
 }
 
+variable "gcs_bucket_location" {
+  description = "The location to use for the GCS buckets"
+  type        = string
+}
+
 variable "linux_machine_type" {
   description = "The type of machine to use for Linux instances"
   type        = string

premerge/main.tf

@@ -50,6 +50,7 @@ module "premerge_cluster_us_central" {
   libcxx_machine_type  = "n2d-standard-32"
   linux_machine_type   = "n2-standard-64"
   windows_machine_type = "n2-standard-32"
+  gcs_bucket_location  = "us-central1"
 }
 
 # We explicitly specify a single zone for the service node pool locations as
@@ -64,6 +65,7 @@ module "premerge_cluster_us_west" {
   linux_machine_type          = "n2d-standard-64"
   windows_machine_type        = "n2d-standard-32"
   service_node_pool_locations = ["us-west1-a"]
+  gcs_bucket_location         = "us-west1"
 }
 
 provider "helm" {