Added gcp terraform support (#6974)

* Added gcp terraform support

* Added http/https firewall rule

* Ignoring lifecycle changes for attached disks on the google_compute_instance

contrib/terraform/gcp/variables.tf

@@ -0,0 +1,72 @@
+variable keyfile_location {
+  description = "Location of the json keyfile to use with the google provider"
+  type        = string
+}
+
+variable region {
+  description = "Region of all resources"
+  type        = string
+}
+
+variable gcp_project_id {
+  description = "ID of the project"
+  type        = string
+}
+
+variable prefix {
+  description = "Prefix for resource names"
+  default     = "default"
+}
+
+variable machines {
+  description = "Cluster machines"
+  type = map(object({
+    node_type = string
+    size      = string
+    zone      = string
+    additional_disks = map(object({
+      size = number
+    }))
+    boot_disk = object({
+      image_name = string
+      size       = number
+    })
+  }))
+}
+
+variable "master_sa_email" {
+  type    = string
+  default = ""
+}
+
+variable "master_sa_scopes" {
+  type    = list(string)
+  default = ["https://www.googleapis.com/auth/cloud-platform"]
+}
+
+variable "worker_sa_email" {
+  type    = string
+  default = ""
+}
+
+variable "worker_sa_scopes" {
+  type    = list(string)
+  default = ["https://www.googleapis.com/auth/cloud-platform"]
+}
+
+variable ssh_pub_key {
+  description = "Path to public SSH key file which is injected into the VMs."
+  type        = string
+}
+
+variable ssh_whitelist {
+  type = list(string)
+}
+
+variable api_server_whitelist {
+  type = list(string)
+}
+
+variable nodeport_whitelist {
+  type = list(string)
+}