improve configurability and resource references for internal ALB (#3654)

* refactor(net-lb-app-ext): improve configurability and resource references

- Allow overriding names for backend buckets and instance groups
- Add optional per-group description with default value
- Use self_link for instance group backend references
- Fix HTTP proxy name to use http_proxy_config

* reverted the instance group reference in backend service back to id instead of self link

* updated all the lb modules for unmanaged instance groups to have flexible names and proper refactorization of http_proxy_cofig in each module

* removed the description variable

* updated the readme.md for the net-lb-app-ext-regional module

* fixed the linting error for the change in versions.tf

---------

Co-authored-by: Julio Castillo <jccb@google.com>
Co-authored-by: Ludovico Magnocavallo <ludomagno@google.com>

modules/net-lb-app-ext/backends.tf

@@ -23,7 +23,7 @@ resource "google_compute_backend_bucket" "default" {
     ? var.project_id
     : each.value.project_id
   )
-  name                    = "${var.name}-${each.key}"
+  name                    = coalesce(each.value.name, "${var.name}-${each.key}")
   bucket_name             = each.value.bucket_name
   compression_mode        = each.value.compression_mode
   custom_response_headers = each.value.custom_response_headers

modules/net-lb-app-ext/groups.tf

@@ -22,8 +22,8 @@ resource "google_compute_instance_group" "default" {
     : each.value.project_id
   )
   zone        = each.value.zone
-  name        = "${var.name}-${each.key}"
-  description = var.description
+  name        = coalesce(each.value.name, "${var.name}-${each.key}")
+  description = each.value.description
   instances   = each.value.instances
 
   dynamic "named_port" {

modules/net-lb-app-ext/main.tf

@@ -120,10 +120,11 @@ resource "google_compute_target_http_proxy" "new" {
   count = (
     var.protocol == "HTTP" && !var.use_classic_version ? 1 : 0
   )
-  project     = var.project_id
-  name        = coalesce(var.https_proxy_config.name, var.name)
-  description = var.http_proxy_config.description
-  url_map     = google_compute_url_map.default.id
+  project                     = var.project_id
+  name                        = coalesce(var.http_proxy_config.name, var.name)
+  description                 = var.http_proxy_config.description
+  http_keep_alive_timeout_sec = var.http_proxy_config.http_keepalive_timeout
+  url_map                     = google_compute_url_map.default.id
 }
 
 resource "google_compute_target_https_proxy" "new" {

modules/net-lb-app-ext/variables.tf

@@ -18,6 +18,7 @@ variable "backend_buckets_config" {
   description = "Backend buckets configuration."
   type = map(object({
     bucket_name             = string
+    name                    = optional(string)
     compression_mode        = optional(string)
     custom_response_headers = optional(list(string))
     description             = optional(string)
@@ -78,6 +79,8 @@ variable "forwarding_rules_config" {
 variable "group_configs" {
   description = "Optional unmanaged groups to create. Can be referenced in backends via key or outputs."
   type = map(object({
+    name        = optional(string)
+    description = optional(string, "Terraform managed.")
     zone        = string
     instances   = optional(list(string))
     named_ports = optional(map(number), {})