Switch Typhoon configuration away from Fedora CoreOS / delete 1.18 stage (#1147)

Author: alexsomesan

kubernetes/test-infra/typhoon-aws/README.md

@@ -19,10 +19,10 @@ Example:
 ## Versions
 
 You can set the desired version of Kubernetes via the `kubernetes_version` Terraform variable. If unset it defaults to 
-version 1.18.
+version 1.20.
 Example:
 ```
-export TF_VAR_kubernetes_version=1.18
+export TF_VAR_kubernetes_version=1.20
 ```
 
 This configuration is only compatible with Terraform 0.13 and up due to the use of the count-on-module feature which is not available in earlier versions.

kubernetes/test-infra/typhoon-aws/module_1_19.tf

@@ -6,11 +6,11 @@ locals {
     enabled_1_19 = length(regexall("v?1.19.?[0-9]{0,2}", var.kubernetes_version))
 }
 
-# This module builds a 1.19.x Typhoon cluster. It is mutually exlusive to the 1.18.x module.
+# This module builds a 1.19.x Typhoon cluster. It is mutually exlusive to other modules of different versions.
 #
 module "typhoon-acc-1_19" {
   count = local.enabled_1_19
-  source = "git::https://github.com/poseidon/typhoon//aws/fedora-coreos/kubernetes?ref=v1.19.0"
+  source = "git::https://github.com/poseidon/typhoon//aws/flatcar-linux/kubernetes?ref=v1.19.4"
 
   cluster_name = var.cluster_name
   dns_zone     = var.base_domain

kubernetes/test-infra/typhoon-aws/module_1_18.tf renamed to kubernetes/test-infra/typhoon-aws/module_1_20.tf

@@ -1,16 +1,16 @@
 locals {
-    # This local gets a value of 1 when the 'kubernetes_version' input variable requests a 1.18.x version, otherwise it is 0.
-    # It's used to enable the module and resources specific to 1.18.x as a workaround for not being able 
+    # This local gets a value of 1 when the 'kubernetes_version' input variable requests a 1.20.x version, otherwise it is 0.
+    # It's used to enable the module and resources specific to 1.20.x as a workaround for not being able 
     # to interpolate variables in the 'source' attribute of a module block.
     #
-    enabled_1_18 = length(regexall("v?1.18.?[0-9]{0,2}", var.kubernetes_version))
+    enabled_1_20 = length(regexall("v?1.20.?[0-9]{0,2}", var.kubernetes_version))
 }
 
-# This module builds a 1.19.x Typhoon cluster. It is mutually exlusive to the 1.18.x module.
+# This module builds a 1.20.x Typhoon cluster. It is mutually exlusive to other modules of different versions.
 #
-module "typhoon-acc-1_18" {
-  count = local.enabled_1_18
-  source = "git::https://github.com/poseidon/typhoon//aws/fedora-coreos/kubernetes?ref=v1.18.8"
+module "typhoon-acc-1_20" {
+  count = local.enabled_1_20
+  source = "git::https://github.com/poseidon/typhoon//aws/flatcar-linux/kubernetes?ref=v1.20.2"
 
   cluster_name = var.cluster_name
   dns_zone     = var.base_domain
@@ -25,8 +25,8 @@ module "typhoon-acc-1_18" {
   controller_type = var.worker_type
 }
 
-resource "local_file" "typhoon-acc_1_18" {
-  count = local.enabled_1_18
-  content  = module.typhoon-acc-1_18[0].kubeconfig-admin
+resource "local_file" "typhoon-acc-1_20" {
+  count = local.enabled_1_20
+  content  = module.typhoon-acc-1_20[0].kubeconfig-admin
   filename = local.kubeconfig_path
 }

kubernetes/test-infra/typhoon-aws/variables.tf

@@ -8,7 +8,7 @@ variable "cluster_name" {
 
 variable "kubernetes_version" {
     type = string
-    default = "1.18.8"
+    default = "1.20.2"
 }
 
 variable "controller_count" {