Terraform support for UpCloud (#7360)

* terraform support for UpCloud

* terraform support for UpCloud

* terraform support for UpCloud

* terraform support for UpCloud

* terraform support for UpCloud

* terraform support for UpCloud

* terraform support for UpCloud

* Updates to README.md and main.tf files

* formatting and updating readme

* added a .terraform_validate CI job

* fixed format issue

* added sample inventory

* added symbolic link to group_vars

* added missing tf variables and minor fixes

* added text formatting

* minor formatting fixes

contrib/terraform/upcloud/modules/kubernetes-cluster/variables.tf

@@ -0,0 +1,25 @@
+variable "zone" {
+  type = string
+}
+
+variable "hostname"{
+ default ="example.com"
+}
+
+variable "template_name"{}
+
+variable "username"{}
+
+variable "machines" {
+  description = "Cluster machines"
+  type = map(object({
+    node_type = string
+    cpu      = string
+    mem      = string
+    disk_size =  number
+  }))
+}
+
+variable "ssh_public_keys" {
+  type = list(string)
+}