coredns use version tag to 1.8.0

Let docker daemon figure out the architecture and use version 1.8.0

closes: #374
Signed-off-by: knrt10 <kautilya@kinvolk.io>

assets/terraform-modules/bootkube/assets.tf

@@ -68,7 +68,7 @@ resource "local_file" "kubernetes" {
     kube_controller_manager_image = var.container_images["kube_controller_manager"]
     kube_scheduler_image          = var.container_images["kube_scheduler"]
     kube_proxy_image              = var.container_images["kube_proxy"]
-    coredns_image                 = "${var.container_images["coredns"]}${var.container_arch}"
+    coredns_image                 = var.container_images["coredns"]
     control_plane_replicas        = max(2, length(var.etcd_servers))
     cloud_provider                = var.cloud_provider
     pod_cidr                      = var.pod_cidr

assets/terraform-modules/bootkube/variables.tf

@@ -91,7 +91,7 @@ variable "container_arch" {
 }
 
 variable "container_images" {
-  description = "Container images to use (the coredns entry will get -$${var.container_arch} appended)"
+  description = "Container images to use"
   type        = map(string)
 
   default = {
@@ -100,7 +100,7 @@ variable "container_images" {
     calico_controllers      = "calico/kube-controllers:v3.16.4"
     flexvol_driver_image    = "calico/pod2daemon-flexvol:v3.16.4"
     kubelet_image           = "quay.io/poseidon/kubelet:v1.19.4"
-    coredns                 = "coredns/coredns:coredns-"
+    coredns                 = "coredns/coredns:1.8.0"
     pod_checkpointer        = "kinvolk/pod-checkpointer:d1c58443fe7d7d33aa5bf7d80d65d299be6e5847"
     kube_apiserver          = "k8s.gcr.io/kube-apiserver:v1.19.4"
     kube_controller_manager = "k8s.gcr.io/kube-controller-manager:v1.19.4"