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/main.tf

@@ -0,0 +1,55 @@
+
+terraform {
+  required_version = ">= 0.13.0"
+}
+provider "upcloud" {
+  # Your UpCloud credentials are read from  environment variables:
+  username = var.UPCLOUD_USERNAME
+  password = var.UPCLOUD_PASSWORD
+}
+
+module "kubernetes" {
+  source = "./modules/kubernetes-cluster"
+
+  zone     = var.zone
+  hostname = var.hostname
+
+  template_name = var.template_name
+  username      = var.username
+
+  machines = var.machines
+
+  ssh_public_keys = var.ssh_public_keys
+}
+
+#
+# Generate ansible inventory
+#
+
+data "template_file" "inventory" {
+  template = file("${path.module}/templates/inventory.tpl")
+
+  vars = {
+    connection_strings_master = join("\n", formatlist("%s ansible_user=ubuntu ansible_host=%s etcd_member_name=etcd%d",
+      keys(module.kubernetes.master_ip),
+      values(module.kubernetes.master_ip),
+    range(1, length(module.kubernetes.master_ip) + 1)))
+    connection_strings_worker = join("\n", formatlist("%s ansible_user=ubuntu ansible_host=%s",
+      keys(module.kubernetes.worker_ip),
+    values(module.kubernetes.worker_ip)))
+    list_master = join("\n", formatlist("%s",
+    keys(module.kubernetes.master_ip)))
+    list_worker = join("\n", formatlist("%s",
+    keys(module.kubernetes.worker_ip)))
+  }
+}
+
+resource "null_resource" "inventories" {
+  provisioner "local-exec" {
+    command = "echo '${data.template_file.inventory.rendered}' > ${var.inventory_file}"
+  }
+
+  triggers = {
+    template = data.template_file.inventory.rendered
+  }
+}