From 6a16a8fa29ca7f71a8d9c1006c1a4581d84cd5d8 Mon Sep 17 00:00:00 2001
From: Eric Zhao <zhaoe@google.com>
Date: Tue, 15 Aug 2023 10:23:03 +1000
Subject: [PATCH] fix: random zones only when zones are not provided

---
 autogen/main/cluster.tf.tmpl                           |  4 ++--
 autogen/main/main.tf.tmpl                              | 10 +++++++---
 cluster.tf                                             |  6 +++---
 main.tf                                                | 10 +++++++---
 modules/beta-autopilot-private-cluster/cluster.tf      |  2 +-
 modules/beta-autopilot-private-cluster/main.tf         | 10 +++++++---
 modules/beta-autopilot-public-cluster/cluster.tf       |  2 +-
 modules/beta-autopilot-public-cluster/main.tf          | 10 +++++++---
 modules/beta-private-cluster-update-variant/cluster.tf |  6 +++---
 modules/beta-private-cluster-update-variant/main.tf    | 10 +++++++---
 modules/beta-private-cluster/cluster.tf                |  6 +++---
 modules/beta-private-cluster/main.tf                   | 10 +++++++---
 modules/beta-public-cluster-update-variant/cluster.tf  |  6 +++---
 modules/beta-public-cluster-update-variant/main.tf     | 10 +++++++---
 modules/beta-public-cluster/cluster.tf                 |  6 +++---
 modules/beta-public-cluster/main.tf                    | 10 +++++++---
 modules/private-cluster-update-variant/cluster.tf      |  6 +++---
 modules/private-cluster-update-variant/main.tf         | 10 +++++++---
 modules/private-cluster/cluster.tf                     |  6 +++---
 modules/private-cluster/main.tf                        | 10 +++++++---
 20 files changed, 95 insertions(+), 55 deletions(-)

diff --git a/autogen/main/cluster.tf.tmpl b/autogen/main/cluster.tf.tmpl
index 71e9720fa1..ce869c59ad 100644
--- a/autogen/main/cluster.tf.tmpl
+++ b/autogen/main/cluster.tf.tmpl
@@ -83,7 +83,7 @@ resource "google_container_cluster" "primary" {
     disabled = var.disable_default_snat
   }
 
-  min_master_version = var.release_channel == null || var.release_channel == "UNSPECIFIED" ? local.master_version : var.kubernetes_version == "latest" ? null : var.kubernetes_version
+  min_master_version = var.release_channel == "UNSPECIFIED" ? local.master_version : var.kubernetes_version == "latest" ? null : var.kubernetes_version
 
 {% if beta_cluster and autopilot_cluster != true %}
   dynamic "cluster_telemetry" {
@@ -649,7 +649,7 @@ resource "google_container_node_pool" "windows_pools" {
   project  = var.project_id
   location = local.location
   // use node_locations if provided, defaults to cluster level node_locations if not specified
-  node_locations = lookup(each.value, "node_locations", "") != "" ? split(",", each.value["node_locations"]) : null
+  node_locations = local.node_locations
 
   cluster = google_container_cluster.primary.name
 
diff --git a/autogen/main/main.tf.tmpl b/autogen/main/main.tf.tmpl
index 6bb3477605..0a83acd52f 100644
--- a/autogen/main/main.tf.tmpl
+++ b/autogen/main/main.tf.tmpl
@@ -20,6 +20,8 @@
   Get available zones in region
  *****************************************/
 data "google_compute_zones" "available" {
+  count        = length(var.zones) == 0 ? 1 : 0
+
   {% if beta_cluster %}
   provider = google-beta
   {% else %}
@@ -31,7 +33,9 @@ data "google_compute_zones" "available" {
 }
 
 resource "random_shuffle" "available_zones" {
-  input        = data.google_compute_zones.available.names
+  count        = length(var.zones) == 0 ? 1 : 0
+
+  input        = data.google_compute_zones.available[0].names
   result_count = 3
 }
 
@@ -43,7 +47,7 @@ locals {
   location = var.regional ? var.region : var.zones[0]
   region   = var.regional ? var.region : join("-", slice(split("-", var.zones[0]), 0, 2))
   // for regional cluster - use var.zones if provided, use available otherwise, for zonal cluster use var.zones with first element extracted
-  node_locations = var.regional ? coalescelist(compact(var.zones), sort(random_shuffle.available_zones.result)) : slice(var.zones, 1, length(var.zones))
+  node_locations = var.regional ? coalescelist(compact(var.zones), try(sort(random_shuffle.available_zones[0].result), [])) : slice(var.zones, 1, length(var.zones))
   // Kubernetes version
   master_version_regional = var.kubernetes_version != "latest" ? var.kubernetes_version : data.google_container_engine_versions.region.latest_master_version
   master_version_zonal    = var.kubernetes_version != "latest" ? var.kubernetes_version : data.google_container_engine_versions.zone.latest_master_version
@@ -245,6 +249,6 @@ data "google_container_engine_versions" "zone" {
   //
   //     data.google_container_engine_versions.zone: Cannot determine zone: set in this resource, or set provider-level zone.
   //
-  location = local.zone_count == 0 ? data.google_compute_zones.available.names[0] : var.zones[0]
+  location = local.zone_count == 0 ? data.google_compute_zones.available[0].names : var.zones[0]
   project  = var.project_id
 }
diff --git a/cluster.tf b/cluster.tf
index 4766e785ed..224a21e833 100644
--- a/cluster.tf
+++ b/cluster.tf
@@ -69,7 +69,7 @@ resource "google_container_cluster" "primary" {
     disabled = var.disable_default_snat
   }
 
-  min_master_version = var.release_channel == null || var.release_channel == "UNSPECIFIED" ? local.master_version : var.kubernetes_version == "latest" ? null : var.kubernetes_version
+  min_master_version = var.release_channel == "UNSPECIFIED" ? local.master_version : var.kubernetes_version == "latest" ? null : var.kubernetes_version
 
   # only one of logging/monitoring_service or logging/monitoring_config can be specified
   logging_service = local.logmon_config_is_set ? null : var.logging_service
@@ -371,7 +371,7 @@ resource "google_container_node_pool" "pools" {
   project  = var.project_id
   location = local.location
   // use node_locations if provided, defaults to cluster level node_locations if not specified
-  node_locations = lookup(each.value, "node_locations", "") != "" ? split(",", each.value["node_locations"]) : null
+  node_locations = local.node_locations
 
   cluster = google_container_cluster.primary.name
 
@@ -557,7 +557,7 @@ resource "google_container_node_pool" "windows_pools" {
   project  = var.project_id
   location = local.location
   // use node_locations if provided, defaults to cluster level node_locations if not specified
-  node_locations = lookup(each.value, "node_locations", "") != "" ? split(",", each.value["node_locations"]) : null
+  node_locations = local.node_locations
 
   cluster = google_container_cluster.primary.name
 
diff --git a/main.tf b/main.tf
index 8c4cba5217..200e97fb9c 100644
--- a/main.tf
+++ b/main.tf
@@ -20,6 +20,8 @@
   Get available zones in region
  *****************************************/
 data "google_compute_zones" "available" {
+  count = length(var.zones) == 0 ? 1 : 0
+
   provider = google
 
   project = var.project_id
@@ -27,7 +29,9 @@ data "google_compute_zones" "available" {
 }
 
 resource "random_shuffle" "available_zones" {
-  input        = data.google_compute_zones.available.names
+  count = length(var.zones) == 0 ? 1 : 0
+
+  input        = data.google_compute_zones.available[0].names
   result_count = 3
 }
 
@@ -39,7 +43,7 @@ locals {
   location = var.regional ? var.region : var.zones[0]
   region   = var.regional ? var.region : join("-", slice(split("-", var.zones[0]), 0, 2))
   // for regional cluster - use var.zones if provided, use available otherwise, for zonal cluster use var.zones with first element extracted
-  node_locations = var.regional ? coalescelist(compact(var.zones), sort(random_shuffle.available_zones.result)) : slice(var.zones, 1, length(var.zones))
+  node_locations = var.regional ? coalescelist(compact(var.zones), try(sort(random_shuffle.available_zones[0].result), [])) : slice(var.zones, 1, length(var.zones))
   // Kubernetes version
   master_version_regional = var.kubernetes_version != "latest" ? var.kubernetes_version : data.google_container_engine_versions.region.latest_master_version
   master_version_zonal    = var.kubernetes_version != "latest" ? var.kubernetes_version : data.google_container_engine_versions.zone.latest_master_version
@@ -175,6 +179,6 @@ data "google_container_engine_versions" "zone" {
   //
   //     data.google_container_engine_versions.zone: Cannot determine zone: set in this resource, or set provider-level zone.
   //
-  location = local.zone_count == 0 ? data.google_compute_zones.available.names[0] : var.zones[0]
+  location = local.zone_count == 0 ? data.google_compute_zones.available[0].names : var.zones[0]
   project  = var.project_id
 }
diff --git a/modules/beta-autopilot-private-cluster/cluster.tf b/modules/beta-autopilot-private-cluster/cluster.tf
index 5d836127bc..23b583d649 100644
--- a/modules/beta-autopilot-private-cluster/cluster.tf
+++ b/modules/beta-autopilot-private-cluster/cluster.tf
@@ -67,7 +67,7 @@ resource "google_container_cluster" "primary" {
     disabled = var.disable_default_snat
   }
 
-  min_master_version = var.release_channel == null || var.release_channel == "UNSPECIFIED" ? local.master_version : var.kubernetes_version == "latest" ? null : var.kubernetes_version
+  min_master_version = var.release_channel == "UNSPECIFIED" ? local.master_version : var.kubernetes_version == "latest" ? null : var.kubernetes_version
 
   cluster_autoscaling {
     dynamic "auto_provisioning_defaults" {
diff --git a/modules/beta-autopilot-private-cluster/main.tf b/modules/beta-autopilot-private-cluster/main.tf
index 241b1aa3d9..a9f9d7a5e1 100644
--- a/modules/beta-autopilot-private-cluster/main.tf
+++ b/modules/beta-autopilot-private-cluster/main.tf
@@ -20,6 +20,8 @@
   Get available zones in region
  *****************************************/
 data "google_compute_zones" "available" {
+  count = length(var.zones) == 0 ? 1 : 0
+
   provider = google-beta
 
   project = var.project_id
@@ -27,7 +29,9 @@ data "google_compute_zones" "available" {
 }
 
 resource "random_shuffle" "available_zones" {
-  input        = data.google_compute_zones.available.names
+  count = length(var.zones) == 0 ? 1 : 0
+
+  input        = data.google_compute_zones.available[0].names
   result_count = 3
 }
 
@@ -39,7 +43,7 @@ locals {
   location = var.regional ? var.region : var.zones[0]
   region   = var.regional ? var.region : join("-", slice(split("-", var.zones[0]), 0, 2))
   // for regional cluster - use var.zones if provided, use available otherwise, for zonal cluster use var.zones with first element extracted
-  node_locations = var.regional ? coalescelist(compact(var.zones), sort(random_shuffle.available_zones.result)) : slice(var.zones, 1, length(var.zones))
+  node_locations = var.regional ? coalescelist(compact(var.zones), try(sort(random_shuffle.available_zones[0].result), [])) : slice(var.zones, 1, length(var.zones))
   // Kubernetes version
   master_version_regional = var.kubernetes_version != "latest" ? var.kubernetes_version : data.google_container_engine_versions.region.latest_master_version
   master_version_zonal    = var.kubernetes_version != "latest" ? var.kubernetes_version : data.google_container_engine_versions.zone.latest_master_version
@@ -143,6 +147,6 @@ data "google_container_engine_versions" "zone" {
   //
   //     data.google_container_engine_versions.zone: Cannot determine zone: set in this resource, or set provider-level zone.
   //
-  location = local.zone_count == 0 ? data.google_compute_zones.available.names[0] : var.zones[0]
+  location = local.zone_count == 0 ? data.google_compute_zones.available[0].names : var.zones[0]
   project  = var.project_id
 }
diff --git a/modules/beta-autopilot-public-cluster/cluster.tf b/modules/beta-autopilot-public-cluster/cluster.tf
index 75e6e67f31..3e3c907726 100644
--- a/modules/beta-autopilot-public-cluster/cluster.tf
+++ b/modules/beta-autopilot-public-cluster/cluster.tf
@@ -67,7 +67,7 @@ resource "google_container_cluster" "primary" {
     disabled = var.disable_default_snat
   }
 
-  min_master_version = var.release_channel == null || var.release_channel == "UNSPECIFIED" ? local.master_version : var.kubernetes_version == "latest" ? null : var.kubernetes_version
+  min_master_version = var.release_channel == "UNSPECIFIED" ? local.master_version : var.kubernetes_version == "latest" ? null : var.kubernetes_version
 
   cluster_autoscaling {
     dynamic "auto_provisioning_defaults" {
diff --git a/modules/beta-autopilot-public-cluster/main.tf b/modules/beta-autopilot-public-cluster/main.tf
index f9c8f12b1e..2e0256d8f1 100644
--- a/modules/beta-autopilot-public-cluster/main.tf
+++ b/modules/beta-autopilot-public-cluster/main.tf
@@ -20,6 +20,8 @@
   Get available zones in region
  *****************************************/
 data "google_compute_zones" "available" {
+  count = length(var.zones) == 0 ? 1 : 0
+
   provider = google-beta
 
   project = var.project_id
@@ -27,7 +29,9 @@ data "google_compute_zones" "available" {
 }
 
 resource "random_shuffle" "available_zones" {
-  input        = data.google_compute_zones.available.names
+  count = length(var.zones) == 0 ? 1 : 0
+
+  input        = data.google_compute_zones.available[0].names
   result_count = 3
 }
 
@@ -39,7 +43,7 @@ locals {
   location = var.regional ? var.region : var.zones[0]
   region   = var.regional ? var.region : join("-", slice(split("-", var.zones[0]), 0, 2))
   // for regional cluster - use var.zones if provided, use available otherwise, for zonal cluster use var.zones with first element extracted
-  node_locations = var.regional ? coalescelist(compact(var.zones), sort(random_shuffle.available_zones.result)) : slice(var.zones, 1, length(var.zones))
+  node_locations = var.regional ? coalescelist(compact(var.zones), try(sort(random_shuffle.available_zones[0].result), [])) : slice(var.zones, 1, length(var.zones))
   // Kubernetes version
   master_version_regional = var.kubernetes_version != "latest" ? var.kubernetes_version : data.google_container_engine_versions.region.latest_master_version
   master_version_zonal    = var.kubernetes_version != "latest" ? var.kubernetes_version : data.google_container_engine_versions.zone.latest_master_version
@@ -142,6 +146,6 @@ data "google_container_engine_versions" "zone" {
   //
   //     data.google_container_engine_versions.zone: Cannot determine zone: set in this resource, or set provider-level zone.
   //
-  location = local.zone_count == 0 ? data.google_compute_zones.available.names[0] : var.zones[0]
+  location = local.zone_count == 0 ? data.google_compute_zones.available[0].names : var.zones[0]
   project  = var.project_id
 }
diff --git a/modules/beta-private-cluster-update-variant/cluster.tf b/modules/beta-private-cluster-update-variant/cluster.tf
index 14677e0af7..cbdd6e17ad 100644
--- a/modules/beta-private-cluster-update-variant/cluster.tf
+++ b/modules/beta-private-cluster-update-variant/cluster.tf
@@ -75,7 +75,7 @@ resource "google_container_cluster" "primary" {
     disabled = var.disable_default_snat
   }
 
-  min_master_version = var.release_channel == null || var.release_channel == "UNSPECIFIED" ? local.master_version : var.kubernetes_version == "latest" ? null : var.kubernetes_version
+  min_master_version = var.release_channel == "UNSPECIFIED" ? local.master_version : var.kubernetes_version == "latest" ? null : var.kubernetes_version
 
   dynamic "cluster_telemetry" {
     for_each = local.cluster_telemetry_type_is_set ? [1] : []
@@ -553,7 +553,7 @@ resource "google_container_node_pool" "pools" {
   project  = var.project_id
   location = local.location
   // use node_locations if provided, defaults to cluster level node_locations if not specified
-  node_locations = lookup(each.value, "node_locations", "") != "" ? split(",", each.value["node_locations"]) : null
+  node_locations = local.node_locations
 
   cluster = google_container_cluster.primary.name
 
@@ -779,7 +779,7 @@ resource "google_container_node_pool" "windows_pools" {
   project  = var.project_id
   location = local.location
   // use node_locations if provided, defaults to cluster level node_locations if not specified
-  node_locations = lookup(each.value, "node_locations", "") != "" ? split(",", each.value["node_locations"]) : null
+  node_locations = local.node_locations
 
   cluster = google_container_cluster.primary.name
 
diff --git a/modules/beta-private-cluster-update-variant/main.tf b/modules/beta-private-cluster-update-variant/main.tf
index 69a88465d2..118f843b85 100644
--- a/modules/beta-private-cluster-update-variant/main.tf
+++ b/modules/beta-private-cluster-update-variant/main.tf
@@ -20,6 +20,8 @@
   Get available zones in region
  *****************************************/
 data "google_compute_zones" "available" {
+  count = length(var.zones) == 0 ? 1 : 0
+
   provider = google-beta
 
   project = var.project_id
@@ -27,7 +29,9 @@ data "google_compute_zones" "available" {
 }
 
 resource "random_shuffle" "available_zones" {
-  input        = data.google_compute_zones.available.names
+  count = length(var.zones) == 0 ? 1 : 0
+
+  input        = data.google_compute_zones.available[0].names
   result_count = 3
 }
 
@@ -39,7 +43,7 @@ locals {
   location = var.regional ? var.region : var.zones[0]
   region   = var.regional ? var.region : join("-", slice(split("-", var.zones[0]), 0, 2))
   // for regional cluster - use var.zones if provided, use available otherwise, for zonal cluster use var.zones with first element extracted
-  node_locations = var.regional ? coalescelist(compact(var.zones), sort(random_shuffle.available_zones.result)) : slice(var.zones, 1, length(var.zones))
+  node_locations = var.regional ? coalescelist(compact(var.zones), try(sort(random_shuffle.available_zones[0].result), [])) : slice(var.zones, 1, length(var.zones))
   // Kubernetes version
   master_version_regional = var.kubernetes_version != "latest" ? var.kubernetes_version : data.google_container_engine_versions.region.latest_master_version
   master_version_zonal    = var.kubernetes_version != "latest" ? var.kubernetes_version : data.google_container_engine_versions.zone.latest_master_version
@@ -203,6 +207,6 @@ data "google_container_engine_versions" "zone" {
   //
   //     data.google_container_engine_versions.zone: Cannot determine zone: set in this resource, or set provider-level zone.
   //
-  location = local.zone_count == 0 ? data.google_compute_zones.available.names[0] : var.zones[0]
+  location = local.zone_count == 0 ? data.google_compute_zones.available[0].names : var.zones[0]
   project  = var.project_id
 }
diff --git a/modules/beta-private-cluster/cluster.tf b/modules/beta-private-cluster/cluster.tf
index 9daec34d24..56e84c4a68 100644
--- a/modules/beta-private-cluster/cluster.tf
+++ b/modules/beta-private-cluster/cluster.tf
@@ -75,7 +75,7 @@ resource "google_container_cluster" "primary" {
     disabled = var.disable_default_snat
   }
 
-  min_master_version = var.release_channel == null || var.release_channel == "UNSPECIFIED" ? local.master_version : var.kubernetes_version == "latest" ? null : var.kubernetes_version
+  min_master_version = var.release_channel == "UNSPECIFIED" ? local.master_version : var.kubernetes_version == "latest" ? null : var.kubernetes_version
 
   dynamic "cluster_telemetry" {
     for_each = local.cluster_telemetry_type_is_set ? [1] : []
@@ -459,7 +459,7 @@ resource "google_container_node_pool" "pools" {
   project  = var.project_id
   location = local.location
   // use node_locations if provided, defaults to cluster level node_locations if not specified
-  node_locations = lookup(each.value, "node_locations", "") != "" ? split(",", each.value["node_locations"]) : null
+  node_locations = local.node_locations
 
   cluster = google_container_cluster.primary.name
 
@@ -684,7 +684,7 @@ resource "google_container_node_pool" "windows_pools" {
   project  = var.project_id
   location = local.location
   // use node_locations if provided, defaults to cluster level node_locations if not specified
-  node_locations = lookup(each.value, "node_locations", "") != "" ? split(",", each.value["node_locations"]) : null
+  node_locations = local.node_locations
 
   cluster = google_container_cluster.primary.name
 
diff --git a/modules/beta-private-cluster/main.tf b/modules/beta-private-cluster/main.tf
index 69a88465d2..118f843b85 100644
--- a/modules/beta-private-cluster/main.tf
+++ b/modules/beta-private-cluster/main.tf
@@ -20,6 +20,8 @@
   Get available zones in region
  *****************************************/
 data "google_compute_zones" "available" {
+  count = length(var.zones) == 0 ? 1 : 0
+
   provider = google-beta
 
   project = var.project_id
@@ -27,7 +29,9 @@ data "google_compute_zones" "available" {
 }
 
 resource "random_shuffle" "available_zones" {
-  input        = data.google_compute_zones.available.names
+  count = length(var.zones) == 0 ? 1 : 0
+
+  input        = data.google_compute_zones.available[0].names
   result_count = 3
 }
 
@@ -39,7 +43,7 @@ locals {
   location = var.regional ? var.region : var.zones[0]
   region   = var.regional ? var.region : join("-", slice(split("-", var.zones[0]), 0, 2))
   // for regional cluster - use var.zones if provided, use available otherwise, for zonal cluster use var.zones with first element extracted
-  node_locations = var.regional ? coalescelist(compact(var.zones), sort(random_shuffle.available_zones.result)) : slice(var.zones, 1, length(var.zones))
+  node_locations = var.regional ? coalescelist(compact(var.zones), try(sort(random_shuffle.available_zones[0].result), [])) : slice(var.zones, 1, length(var.zones))
   // Kubernetes version
   master_version_regional = var.kubernetes_version != "latest" ? var.kubernetes_version : data.google_container_engine_versions.region.latest_master_version
   master_version_zonal    = var.kubernetes_version != "latest" ? var.kubernetes_version : data.google_container_engine_versions.zone.latest_master_version
@@ -203,6 +207,6 @@ data "google_container_engine_versions" "zone" {
   //
   //     data.google_container_engine_versions.zone: Cannot determine zone: set in this resource, or set provider-level zone.
   //
-  location = local.zone_count == 0 ? data.google_compute_zones.available.names[0] : var.zones[0]
+  location = local.zone_count == 0 ? data.google_compute_zones.available[0].names : var.zones[0]
   project  = var.project_id
 }
diff --git a/modules/beta-public-cluster-update-variant/cluster.tf b/modules/beta-public-cluster-update-variant/cluster.tf
index a4a9b4d379..6cd68e4192 100644
--- a/modules/beta-public-cluster-update-variant/cluster.tf
+++ b/modules/beta-public-cluster-update-variant/cluster.tf
@@ -75,7 +75,7 @@ resource "google_container_cluster" "primary" {
     disabled = var.disable_default_snat
   }
 
-  min_master_version = var.release_channel == null || var.release_channel == "UNSPECIFIED" ? local.master_version : var.kubernetes_version == "latest" ? null : var.kubernetes_version
+  min_master_version = var.release_channel == "UNSPECIFIED" ? local.master_version : var.kubernetes_version == "latest" ? null : var.kubernetes_version
 
   dynamic "cluster_telemetry" {
     for_each = local.cluster_telemetry_type_is_set ? [1] : []
@@ -534,7 +534,7 @@ resource "google_container_node_pool" "pools" {
   project  = var.project_id
   location = local.location
   // use node_locations if provided, defaults to cluster level node_locations if not specified
-  node_locations = lookup(each.value, "node_locations", "") != "" ? split(",", each.value["node_locations"]) : null
+  node_locations = local.node_locations
 
   cluster = google_container_cluster.primary.name
 
@@ -760,7 +760,7 @@ resource "google_container_node_pool" "windows_pools" {
   project  = var.project_id
   location = local.location
   // use node_locations if provided, defaults to cluster level node_locations if not specified
-  node_locations = lookup(each.value, "node_locations", "") != "" ? split(",", each.value["node_locations"]) : null
+  node_locations = local.node_locations
 
   cluster = google_container_cluster.primary.name
 
diff --git a/modules/beta-public-cluster-update-variant/main.tf b/modules/beta-public-cluster-update-variant/main.tf
index 30220c7cc4..fedb05b7dd 100644
--- a/modules/beta-public-cluster-update-variant/main.tf
+++ b/modules/beta-public-cluster-update-variant/main.tf
@@ -20,6 +20,8 @@
   Get available zones in region
  *****************************************/
 data "google_compute_zones" "available" {
+  count = length(var.zones) == 0 ? 1 : 0
+
   provider = google-beta
 
   project = var.project_id
@@ -27,7 +29,9 @@ data "google_compute_zones" "available" {
 }
 
 resource "random_shuffle" "available_zones" {
-  input        = data.google_compute_zones.available.names
+  count = length(var.zones) == 0 ? 1 : 0
+
+  input        = data.google_compute_zones.available[0].names
   result_count = 3
 }
 
@@ -39,7 +43,7 @@ locals {
   location = var.regional ? var.region : var.zones[0]
   region   = var.regional ? var.region : join("-", slice(split("-", var.zones[0]), 0, 2))
   // for regional cluster - use var.zones if provided, use available otherwise, for zonal cluster use var.zones with first element extracted
-  node_locations = var.regional ? coalescelist(compact(var.zones), sort(random_shuffle.available_zones.result)) : slice(var.zones, 1, length(var.zones))
+  node_locations = var.regional ? coalescelist(compact(var.zones), try(sort(random_shuffle.available_zones[0].result), [])) : slice(var.zones, 1, length(var.zones))
   // Kubernetes version
   master_version_regional = var.kubernetes_version != "latest" ? var.kubernetes_version : data.google_container_engine_versions.region.latest_master_version
   master_version_zonal    = var.kubernetes_version != "latest" ? var.kubernetes_version : data.google_container_engine_versions.zone.latest_master_version
@@ -202,6 +206,6 @@ data "google_container_engine_versions" "zone" {
   //
   //     data.google_container_engine_versions.zone: Cannot determine zone: set in this resource, or set provider-level zone.
   //
-  location = local.zone_count == 0 ? data.google_compute_zones.available.names[0] : var.zones[0]
+  location = local.zone_count == 0 ? data.google_compute_zones.available[0].names : var.zones[0]
   project  = var.project_id
 }
diff --git a/modules/beta-public-cluster/cluster.tf b/modules/beta-public-cluster/cluster.tf
index 72376a4e08..545e607f9b 100644
--- a/modules/beta-public-cluster/cluster.tf
+++ b/modules/beta-public-cluster/cluster.tf
@@ -75,7 +75,7 @@ resource "google_container_cluster" "primary" {
     disabled = var.disable_default_snat
   }
 
-  min_master_version = var.release_channel == null || var.release_channel == "UNSPECIFIED" ? local.master_version : var.kubernetes_version == "latest" ? null : var.kubernetes_version
+  min_master_version = var.release_channel == "UNSPECIFIED" ? local.master_version : var.kubernetes_version == "latest" ? null : var.kubernetes_version
 
   dynamic "cluster_telemetry" {
     for_each = local.cluster_telemetry_type_is_set ? [1] : []
@@ -440,7 +440,7 @@ resource "google_container_node_pool" "pools" {
   project  = var.project_id
   location = local.location
   // use node_locations if provided, defaults to cluster level node_locations if not specified
-  node_locations = lookup(each.value, "node_locations", "") != "" ? split(",", each.value["node_locations"]) : null
+  node_locations = local.node_locations
 
   cluster = google_container_cluster.primary.name
 
@@ -665,7 +665,7 @@ resource "google_container_node_pool" "windows_pools" {
   project  = var.project_id
   location = local.location
   // use node_locations if provided, defaults to cluster level node_locations if not specified
-  node_locations = lookup(each.value, "node_locations", "") != "" ? split(",", each.value["node_locations"]) : null
+  node_locations = local.node_locations
 
   cluster = google_container_cluster.primary.name
 
diff --git a/modules/beta-public-cluster/main.tf b/modules/beta-public-cluster/main.tf
index 30220c7cc4..fedb05b7dd 100644
--- a/modules/beta-public-cluster/main.tf
+++ b/modules/beta-public-cluster/main.tf
@@ -20,6 +20,8 @@
   Get available zones in region
  *****************************************/
 data "google_compute_zones" "available" {
+  count = length(var.zones) == 0 ? 1 : 0
+
   provider = google-beta
 
   project = var.project_id
@@ -27,7 +29,9 @@ data "google_compute_zones" "available" {
 }
 
 resource "random_shuffle" "available_zones" {
-  input        = data.google_compute_zones.available.names
+  count = length(var.zones) == 0 ? 1 : 0
+
+  input        = data.google_compute_zones.available[0].names
   result_count = 3
 }
 
@@ -39,7 +43,7 @@ locals {
   location = var.regional ? var.region : var.zones[0]
   region   = var.regional ? var.region : join("-", slice(split("-", var.zones[0]), 0, 2))
   // for regional cluster - use var.zones if provided, use available otherwise, for zonal cluster use var.zones with first element extracted
-  node_locations = var.regional ? coalescelist(compact(var.zones), sort(random_shuffle.available_zones.result)) : slice(var.zones, 1, length(var.zones))
+  node_locations = var.regional ? coalescelist(compact(var.zones), try(sort(random_shuffle.available_zones[0].result), [])) : slice(var.zones, 1, length(var.zones))
   // Kubernetes version
   master_version_regional = var.kubernetes_version != "latest" ? var.kubernetes_version : data.google_container_engine_versions.region.latest_master_version
   master_version_zonal    = var.kubernetes_version != "latest" ? var.kubernetes_version : data.google_container_engine_versions.zone.latest_master_version
@@ -202,6 +206,6 @@ data "google_container_engine_versions" "zone" {
   //
   //     data.google_container_engine_versions.zone: Cannot determine zone: set in this resource, or set provider-level zone.
   //
-  location = local.zone_count == 0 ? data.google_compute_zones.available.names[0] : var.zones[0]
+  location = local.zone_count == 0 ? data.google_compute_zones.available[0].names : var.zones[0]
   project  = var.project_id
 }
diff --git a/modules/private-cluster-update-variant/cluster.tf b/modules/private-cluster-update-variant/cluster.tf
index 9530a12217..2488222221 100644
--- a/modules/private-cluster-update-variant/cluster.tf
+++ b/modules/private-cluster-update-variant/cluster.tf
@@ -69,7 +69,7 @@ resource "google_container_cluster" "primary" {
     disabled = var.disable_default_snat
   }
 
-  min_master_version = var.release_channel == null || var.release_channel == "UNSPECIFIED" ? local.master_version : var.kubernetes_version == "latest" ? null : var.kubernetes_version
+  min_master_version = var.release_channel == "UNSPECIFIED" ? local.master_version : var.kubernetes_version == "latest" ? null : var.kubernetes_version
 
   # only one of logging/monitoring_service or logging/monitoring_config can be specified
   logging_service = local.logmon_config_is_set ? null : var.logging_service
@@ -484,7 +484,7 @@ resource "google_container_node_pool" "pools" {
   project  = var.project_id
   location = local.location
   // use node_locations if provided, defaults to cluster level node_locations if not specified
-  node_locations = lookup(each.value, "node_locations", "") != "" ? split(",", each.value["node_locations"]) : null
+  node_locations = local.node_locations
 
   cluster = google_container_cluster.primary.name
 
@@ -671,7 +671,7 @@ resource "google_container_node_pool" "windows_pools" {
   project  = var.project_id
   location = local.location
   // use node_locations if provided, defaults to cluster level node_locations if not specified
-  node_locations = lookup(each.value, "node_locations", "") != "" ? split(",", each.value["node_locations"]) : null
+  node_locations = local.node_locations
 
   cluster = google_container_cluster.primary.name
 
diff --git a/modules/private-cluster-update-variant/main.tf b/modules/private-cluster-update-variant/main.tf
index fe1520fca5..875608219a 100644
--- a/modules/private-cluster-update-variant/main.tf
+++ b/modules/private-cluster-update-variant/main.tf
@@ -20,6 +20,8 @@
   Get available zones in region
  *****************************************/
 data "google_compute_zones" "available" {
+  count = length(var.zones) == 0 ? 1 : 0
+
   provider = google
 
   project = var.project_id
@@ -27,7 +29,9 @@ data "google_compute_zones" "available" {
 }
 
 resource "random_shuffle" "available_zones" {
-  input        = data.google_compute_zones.available.names
+  count = length(var.zones) == 0 ? 1 : 0
+
+  input        = data.google_compute_zones.available[0].names
   result_count = 3
 }
 
@@ -39,7 +43,7 @@ locals {
   location = var.regional ? var.region : var.zones[0]
   region   = var.regional ? var.region : join("-", slice(split("-", var.zones[0]), 0, 2))
   // for regional cluster - use var.zones if provided, use available otherwise, for zonal cluster use var.zones with first element extracted
-  node_locations = var.regional ? coalescelist(compact(var.zones), sort(random_shuffle.available_zones.result)) : slice(var.zones, 1, length(var.zones))
+  node_locations = var.regional ? coalescelist(compact(var.zones), try(sort(random_shuffle.available_zones[0].result), [])) : slice(var.zones, 1, length(var.zones))
   // Kubernetes version
   master_version_regional = var.kubernetes_version != "latest" ? var.kubernetes_version : data.google_container_engine_versions.region.latest_master_version
   master_version_zonal    = var.kubernetes_version != "latest" ? var.kubernetes_version : data.google_container_engine_versions.zone.latest_master_version
@@ -176,6 +180,6 @@ data "google_container_engine_versions" "zone" {
   //
   //     data.google_container_engine_versions.zone: Cannot determine zone: set in this resource, or set provider-level zone.
   //
-  location = local.zone_count == 0 ? data.google_compute_zones.available.names[0] : var.zones[0]
+  location = local.zone_count == 0 ? data.google_compute_zones.available[0].names : var.zones[0]
   project  = var.project_id
 }
diff --git a/modules/private-cluster/cluster.tf b/modules/private-cluster/cluster.tf
index 693fcff790..82c977bcb3 100644
--- a/modules/private-cluster/cluster.tf
+++ b/modules/private-cluster/cluster.tf
@@ -69,7 +69,7 @@ resource "google_container_cluster" "primary" {
     disabled = var.disable_default_snat
   }
 
-  min_master_version = var.release_channel == null || var.release_channel == "UNSPECIFIED" ? local.master_version : var.kubernetes_version == "latest" ? null : var.kubernetes_version
+  min_master_version = var.release_channel == "UNSPECIFIED" ? local.master_version : var.kubernetes_version == "latest" ? null : var.kubernetes_version
 
   # only one of logging/monitoring_service or logging/monitoring_config can be specified
   logging_service = local.logmon_config_is_set ? null : var.logging_service
@@ -390,7 +390,7 @@ resource "google_container_node_pool" "pools" {
   project  = var.project_id
   location = local.location
   // use node_locations if provided, defaults to cluster level node_locations if not specified
-  node_locations = lookup(each.value, "node_locations", "") != "" ? split(",", each.value["node_locations"]) : null
+  node_locations = local.node_locations
 
   cluster = google_container_cluster.primary.name
 
@@ -576,7 +576,7 @@ resource "google_container_node_pool" "windows_pools" {
   project  = var.project_id
   location = local.location
   // use node_locations if provided, defaults to cluster level node_locations if not specified
-  node_locations = lookup(each.value, "node_locations", "") != "" ? split(",", each.value["node_locations"]) : null
+  node_locations = local.node_locations
 
   cluster = google_container_cluster.primary.name
 
diff --git a/modules/private-cluster/main.tf b/modules/private-cluster/main.tf
index fe1520fca5..875608219a 100644
--- a/modules/private-cluster/main.tf
+++ b/modules/private-cluster/main.tf
@@ -20,6 +20,8 @@
   Get available zones in region
  *****************************************/
 data "google_compute_zones" "available" {
+  count = length(var.zones) == 0 ? 1 : 0
+
   provider = google
 
   project = var.project_id
@@ -27,7 +29,9 @@ data "google_compute_zones" "available" {
 }
 
 resource "random_shuffle" "available_zones" {
-  input        = data.google_compute_zones.available.names
+  count = length(var.zones) == 0 ? 1 : 0
+
+  input        = data.google_compute_zones.available[0].names
   result_count = 3
 }
 
@@ -39,7 +43,7 @@ locals {
   location = var.regional ? var.region : var.zones[0]
   region   = var.regional ? var.region : join("-", slice(split("-", var.zones[0]), 0, 2))
   // for regional cluster - use var.zones if provided, use available otherwise, for zonal cluster use var.zones with first element extracted
-  node_locations = var.regional ? coalescelist(compact(var.zones), sort(random_shuffle.available_zones.result)) : slice(var.zones, 1, length(var.zones))
+  node_locations = var.regional ? coalescelist(compact(var.zones), try(sort(random_shuffle.available_zones[0].result), [])) : slice(var.zones, 1, length(var.zones))
   // Kubernetes version
   master_version_regional = var.kubernetes_version != "latest" ? var.kubernetes_version : data.google_container_engine_versions.region.latest_master_version
   master_version_zonal    = var.kubernetes_version != "latest" ? var.kubernetes_version : data.google_container_engine_versions.zone.latest_master_version
@@ -176,6 +180,6 @@ data "google_container_engine_versions" "zone" {
   //
   //     data.google_container_engine_versions.zone: Cannot determine zone: set in this resource, or set provider-level zone.
   //
-  location = local.zone_count == 0 ? data.google_compute_zones.available.names[0] : var.zones[0]
+  location = local.zone_count == 0 ? data.google_compute_zones.available[0].names : var.zones[0]
   project  = var.project_id
 }