refactor(inputs): use cluster_domain instead of name

The use of `cluster_domain` is clearer than just` name`, which could be interpreted as something
else.

BREAKING CHANGE: Deprecation of `name` variable

fix #53

agent_nodes.tf

@@ -55,7 +55,7 @@ locals {
       )))
 
       immutable_fields_hash = sha1(join("", concat(
-        [var.name],
+        [var.cluster_domain],
         var.global_flags,
         try(agent.flags, []),
       )))

examples/hcloud-k3s/k3s.tf

@@ -1,9 +1,9 @@
 module "k3s" {
   source = "./../.."
 
-  depends_on_ = hcloud_server.agents
-  k3s_version = "latest"
-  name        = "cluster.local"
+  depends_on_    = hcloud_server.agents
+  k3s_version    = "latest"
+  cluster_domain = "cluster.local"
   cidr = {
     pods     = "10.42.0.0/16"
     services = "10.43.0.0/16"

outputs.tf

@@ -20,16 +20,16 @@ output "kube_config" {
         certificate-authority-data = base64encode(local.cluster_ca_certificate)
         server                     = "https://${local.root_server_connection.host}:6443"
       }
-      name = var.name
+      name = var.cluster_domain
     }]
     contexts = [{
       context = {
-        cluster = var.name
+        cluster = var.cluster_domain
         user : "master-user"
       }
-      name = var.name
+      name = var.cluster_domain
     }]
-    current-context = var.name
+    current-context = var.cluster_domain
     kind            = "Config"
     preferences     = {}
     users = [{

server_nodes.tf

@@ -81,7 +81,7 @@ locals {
         [
           "--node-ip ${server.ip}",
           "--node-name '${try(server.name, key)}'",
-          "--cluster-domain '${var.name}'",
+          "--cluster-domain '${var.cluster_domain}'",
           "--cluster-cidr ${var.cidr.pods}",
           "--service-cidr ${var.cidr.services}",
           "--token ${random_password.k3s_cluster_secret.result}",
@@ -100,7 +100,7 @@ locals {
       )))
 
       immutable_fields_hash = sha1(join("", concat(
-        [var.name, var.cidr.pods, var.cidr.services],
+        [var.cluster_domain, var.cidr.pods, var.cidr.services],
         var.global_flags,
         try(server.flags, []),
       )))

variables.tf

@@ -10,6 +10,17 @@ variable "k3s_version" {
 }
 
 variable "name" {
+  description = "K3s cluster domain name (see https://rancher.com/docs/k3s/latest/en/installation/install-options/). This input is deprecated and will be remove in the next major release. Use `cluster_domain` instead."
+  type        = string
+  default     = "!!!DEPRECATED!!!"
+
+  validation {
+    condition     = var.name == "!!!DEPRECATED!!!"
+    error_message = "Variable `name` is deprecated, use `cluster_domain` instead. It will be removed at the next major release."
+  }
+}
+
+variable "cluster_domain" {
   description = "K3s cluster domain name (see https://rancher.com/docs/k3s/latest/en/installation/install-options/)."
   type        = string
   default     = "cluster.local"