use for_each function instead of count in the fourth example

04-instance-with-loadbalancer/00-variables.tf

@@ -37,9 +37,11 @@ variable "network_http" {
   }
 }
 
-variable "desired_capacity_http" {
-  type    = number
-  default = 2
+variable "http_instance_names" {
+  type    = set(string)
+  default = ["http-instance-1",
+             "http-instance-2",
+             "http-instance-3"]
 }
 
 #### VM DB parameters ####
@@ -56,8 +58,9 @@ variable "network_db" {
   }
 }
 
-variable "desired_capacity_db" {
-  type    = number
-  default = 3
+variable "db_instance_names" {
+  type    = set(string)
+  default = ["db-instance-1",
+             "db-instance-2",
+             "db-instance-3"]
 }
-

04-instance-with-loadbalancer/060-instance_http.tf

@@ -3,21 +3,21 @@
 # Create instance
 #
 resource "openstack_compute_instance_v2" "http" {
-  count       = var.desired_capacity_http
-  name        = "http-${count.index}"
+  for_each    = var.http_instance_names
+  name        = each.key
   image_name  = var.image
   flavor_name = var.flavor_http
   key_pair    = openstack_compute_keypair_v2.user_key.name
   user_data   = file("scripts/first-boot.sh")
   network {
-    port = element(openstack_networking_port_v2.http.*.id, count.index)
+    port = openstack_networking_port_v2.http[each.key].id
   }
 }
 
 # Create network port
 resource "openstack_networking_port_v2" "http" {
-  count          = var.desired_capacity_http
-  name           = "port-http-${count.index}"
+  for_each       = var.http_instance_names
+  name           = "port-http-${each.key}"
   network_id     = openstack_networking_network_v2.generic.id
   admin_state_up = true
   security_group_ids = [

04-instance-with-loadbalancer/061-instance_db.tf

@@ -3,21 +3,21 @@
 # Create instance
 #
 resource "openstack_compute_instance_v2" "db" {
-  count       = var.desired_capacity_db
-  name        = "db-${count.index}"
+  for_each    = var.db_instance_names
+  name        = each.key
   image_name  = var.image
   flavor_name = var.flavor_db
   key_pair    = openstack_compute_keypair_v2.user_key.name
   user_data   = file("scripts/first-boot.sh")
   network {
-    port = element(openstack_networking_port_v2.db.*.id, count.index)
+    port = openstack_networking_port_v2.db[each.key].id
   }
 }
 
 # Create network port
 resource "openstack_networking_port_v2" "db" {
-  count          = var.desired_capacity_db
-  name           = "port-db-${count.index}"
+  for_each       = var.db_instance_names
+  name           = "port-db-${each.key}"
   network_id     = openstack_networking_network_v2.generic.id
   admin_state_up = true
   security_group_ids = [

04-instance-with-loadbalancer/070-loadbalancer.tf

@@ -27,11 +27,8 @@ resource "openstack_lb_pool_v2" "http" {
 
 # Add multip instances to pool
 resource "openstack_lb_member_v2" "http" {
-  count = var.desired_capacity_http
-  address = element(
-    openstack_compute_instance_v2.http.*.access_ip_v4,
-    count.index,
-  )
+  for_each      = var.http_instance_names
+  address       = openstack_compute_instance_v2.http[each.key].access_ip_v4
   protocol_port = 80
   pool_id       = openstack_lb_pool_v2.http.id
   subnet_id     = openstack_networking_subnet_v2.http.id
@@ -78,8 +75,8 @@ resource "openstack_lb_pool_v2" "db" {
 
 # Add multip instances to pool
 resource "openstack_lb_member_v2" "db" {
-  count         = var.desired_capacity_db
-  address       = element(openstack_compute_instance_v2.db.*.access_ip_v4, count.index)
+  for_each      = var.db_instance_names
+  address       = openstack_compute_instance_v2.db[each.key].access_ip_v4
   protocol_port = 3306
   pool_id       = openstack_lb_pool_v2.db.id
   subnet_id     = openstack_networking_subnet_v2.db.id