Upcloud: Add possibility to setup cluster using nodes with no public IPs (#11696)

* terraform upcloud: Added possibility to set up nodes with only private IPs

* terraform upcloud: add support for gateway in private zone

* terraform upcloud: split LB proxy protocol config per backend

* terraform upcloud: fix flexible plans

* terraform upcloud: Removed overview of cluster setup

---------

Co-authored-by: davidumea <david.andersson@elastisys.com>

contrib/terraform/upcloud/variables.tf

@@ -32,16 +32,31 @@ variable "private_network_cidr" {
   default     = "172.16.0.0/24"
 }
 
+variable "dns_servers" {
+  description = "DNS servers that will be used by the nodes. Until [this is solved](https://github.com/UpCloudLtd/terraform-provider-upcloud/issues/562) this is done using user_data to reconfigure resolved"
+
+  type    = set(string)
+  default = []
+}
+
+variable "use_public_ips" {
+  description = "If all nodes should get a public IP"
+  type        = bool
+  default     = true
+}
+
 variable "machines" {
   description = "Cluster machines"
 
   type = map(object({
     node_type = string
     plan      = string
-    cpu       = string
-    mem       = string
+    cpu       = optional(number)
+    mem       = optional(number)
     disk_size = number
     server_group : string
+    force_public_ip : optional(bool, false)
+    dns_servers : optional(set(string))
     additional_disks = map(object({
       size = number
       tier = string
@@ -89,6 +104,15 @@ variable "k8s_allowed_remote_ips" {
   default = []
 }
 
+variable "bastion_allowed_remote_ips" {
+  description = "List of IP start/end addresses allowed to SSH to bastion"
+  type = list(object({
+    start_address = string
+    end_address   = string
+  }))
+  default = []
+}
+
 variable "master_allowed_ports" {
   description = "List of ports to allow on masters"
   type = list(object({
@@ -131,11 +155,6 @@ variable "loadbalancer_plan" {
   default     = "development"
 }
 
-variable "loadbalancer_proxy_protocol" {
-  type    = bool
-  default = false
-}
-
 variable "loadbalancer_legacy_network" {
   description = "If the loadbalancer should use the deprecated network field instead of networks blocks. You probably want to have this set to false"
 
@@ -147,6 +166,7 @@ variable "loadbalancers" {
   description = "Load balancers"
 
   type = map(object({
+    proxy_protocol          = bool
     port                    = number
     target_port             = number
     allow_internal_frontend = optional(bool, false)