Address some review comments:

- Create new var, libcxx_machine_type (currently identical to
  linux_machine_type) and use it where appropriate.
- Remove new kubernetes	secrets	"libcxx_github_pat",
  "libcxx_release_github_pat", and "libcxx_next_github_pat"; replace uses of
  them with "linux_github_pat".

Author: cmtice

premerge/gke_cluster/main.tf

@@ -77,7 +77,7 @@ resource "google_container_node_pool" "llvm_premerge_libcxx" {
   }
 
   node_config {
-    machine_type = var.linux_machine_type
+    machine_type = var.libcxx_machine_type
     taint {
       key    = "premerge-platform"
       value  = "linux"

premerge/gke_cluster/variables.tf

@@ -18,6 +18,11 @@ variable "windows_machine_type" {
   type        = string
 }
 
+variable "libcxx_machine_type" {
+  description = "The type of machine to use for libcxx instances (linux)"
+  type        = string
+}
+
 variable "service_node_pool_locations" {
   description = "The location to run the service node pool in"
   type        = list(any)

premerge/main.tf

@@ -47,6 +47,7 @@ module "premerge_cluster_us_central" {
   source               = "./gke_cluster"
   cluster_name         = "llvm-premerge-cluster-us-central"
   region               = "us-central1-a"
+  libcxx_machine_type  = "n2-standard-64"
   linux_machine_type   = "n2-standard-64"
   windows_machine_type = "n2-standard-32"
 }
@@ -59,6 +60,7 @@ module "premerge_cluster_us_west" {
   source                      = "./gke_cluster"
   cluster_name                = "llvm-premerge-cluster-us-west"
   region                      = "us-west1"
+  libcxx_machine_type         = "n2d-standard-64"
   linux_machine_type          = "n2d-standard-64"
   windows_machine_type        = "n2d-standard-32"
   service_node_pool_locations = ["us-west1-a"]

premerge/premerge_resources/main.tf

@@ -64,57 +64,6 @@ resource "kubernetes_secret" "linux_github_pat" {
   depends_on = [kubernetes_namespace.llvm_premerge_linux_runners]
 }
 
-resource "kubernetes_secret" "libcxx_github_pat" {
-  metadata {
-    name      = "github-token"
-    namespace = "llvm-premerge-libcxx-runners"
-  }
-
-  data = {
-    "github_app_id"              = var.github_app_id
-    "github_app_installation_id" = var.github_app_installation_id
-    "github_app_private_key"     = var.github_app_private_key
-  }
-
-  type = "Opaque"
-
-  depends_on = [kubernetes_namespace.llvm_premerge_libcxx_runners]
-}
-
-resource "kubernetes_secret" "libcxx_release_github_pat" {
-  metadata {
-    name      = "github-token"
-    namespace = "llvm-premerge-libcxx-release-runners"
-  }
-
-  data = {
-    "github_app_id"              = var.github_app_id
-    "github_app_installation_id" = var.github_app_installation_id
-    "github_app_private_key"     = var.github_app_private_key
-  }
-
-  type = "Opaque"
-
-  depends_on = [kubernetes_namespace.llvm_premerge_libcxx_release_runners]
-}
-
-resource "kubernetes_secret" "libcxx_next_github_pat" {
-  metadata {
-    name      = "github-token"
-    namespace = "llvm-premerge-libcxx-next-runners"
-  }
-
-  data = {
-    "github_app_id"              = var.github_app_id
-    "github_app_installation_id" = var.github_app_installation_id
-    "github_app_private_key"     = var.github_app_private_key
-  }
-
-  type = "Opaque"
-
-  depends_on = [kubernetes_namespace.llvm_premerge_libcxx_next_runners]
-}
-
 resource "kubernetes_secret" "windows_github_pat" {
   metadata {
     name      = "github-token"
@@ -194,7 +143,7 @@ resource "helm_release" "github_actions_runner_set_libcxx" {
   depends_on = [
     kubernetes_namespace.llvm_premerge_libcxx_runners,
     helm_release.github_actions_runner_controller,
-    kubernetes_secret.libcxx_github_pat,
+    kubernetes_secret.linux_github_pat,
   ]
 }
 
@@ -212,7 +161,7 @@ resource "helm_release" "github_actions_runner_set_libcxx_release" {
   depends_on = [
     kubernetes_namespace.llvm_premerge_libcxx_release_runners,
     helm_release.github_actions_runner_controller,
-    kubernetes_secret.libcxx_release_github_pat,
+    kubernetes_secret.linux_github_pat,
   ]
 }
 
@@ -230,7 +179,7 @@ resource "helm_release" "github_actions_runner_set_libcxx_next" {
   depends_on = [
     kubernetes_namespace.llvm_premerge_libcxx_next_runners,
     helm_release.github_actions_runner_controller,
-    kubernetes_secret.libcxx_next_github_pat,
+    kubernetes_secret.linux_github_pat,
   ]
 }