refactor: Improve validation for node pool priority, eviction policy, and spot max price

Author: tblakex01

modules/aks/main.tf

@@ -93,10 +93,13 @@ resource "azurerm_kubernetes_cluster" "aks" {
 }
 
 locals {
-  # Create a map with spot instance flags for each node pool
+  # Pre-compute normalized values for each node pool
   node_pool_configs = {
     for k, v in var.node_pools : k => {
-      is_spot = lower(v.priority) == "spot"
+      is_spot         = lower(v.priority) == "spot"
+      priority        = lower(v.priority) == "spot" ? "Spot" : "Regular"
+      eviction_policy = lower(v.priority) == "spot" ? title(lower(v.eviction_policy)) : null
+      spot_max_price  = lower(v.priority) == "spot" ? v.spot_max_price : null
     }
   }
 }
@@ -128,25 +131,10 @@ resource "azurerm_kubernetes_cluster_node_pool" "additional" {
     for taint in coalesce(each.value.node_taints, []) : "${taint.key}=${taint.value}:${taint.effect}"
   ]
 
-  # Normalize to the capitalized form expected by the provider
-  priority        = local.node_pool_configs[each.key].is_spot ? "Spot" : "Regular"
-  eviction_policy = local.node_pool_configs[each.key].is_spot ? title(lower(each.value.eviction_policy)) : null
-  spot_max_price  = local.node_pool_configs[each.key].is_spot ? each.value.spot_max_price : null
+  # Use pre-computed normalized values from locals
+  priority        = local.node_pool_configs[each.key].priority
+  eviction_policy = local.node_pool_configs[each.key].eviction_policy
+  spot_max_price  = local.node_pool_configs[each.key].spot_max_price
 
   tags = merge(var.tags, each.value.tags)
-
-  lifecycle {
-    precondition {
-      condition     = contains(["regular", "spot"], lower(each.value.priority))
-      error_message = "Node pool '${each.key}' has invalid priority '${each.value.priority}'. Priority must be either 'Regular' or 'Spot' (case-insensitive)."
-    }
-    precondition {
-      condition     = !local.node_pool_configs[each.key].is_spot || contains(["delete", "deallocate"], lower(each.value.eviction_policy))
-      error_message = "Node pool '${each.key}' has invalid eviction_policy '${each.value.eviction_policy}'. When priority is 'Spot', eviction_policy must be either 'Delete' or 'Deallocate' (case-insensitive)."
-    }
-    precondition {
-      condition     = each.value.spot_max_price >= -1
-      error_message = "Node pool '${each.key}' has invalid spot_max_price '${each.value.spot_max_price}'. The spot_max_price must be greater than or equal to -1."
-    }
-  }
 }

modules/aks/variables.tf

@@ -85,30 +85,32 @@ variable "node_pools" {
     # Spot instance configuration
     priority        = optional(string, "Regular") # Valid values: "Regular" or "Spot" (case-insensitive)
     eviction_policy = optional(string, "Delete")  # Valid values: "Delete" or "Deallocate" (case-insensitive, only used when priority is "Spot")
-    spot_max_price  = optional(number, -1)        # Max price for Spot instances (must be >= -1), -1 uses market price
+    spot_max_price  = optional(number, -1)        # Max price for Spot instances (must be -1 or >= 0), -1 uses market price
   }))
   default = {}
 
   validation {
-    condition = alltrue([
-      for k, v in var.node_pools : contains(["regular", "spot"], lower(v.priority))
-    ])
-    error_message = "Each node pool's priority must be either 'Regular' or 'Spot' (case-insensitive)."
+    condition = length([
+      for k, v in var.node_pools : k
+      if !contains(["regular", "spot"], lower(v.priority))
+    ]) == 0
+    error_message = "Invalid priority values found. ${join(", ", [for k, v in var.node_pools : "Node pool '${k}' has invalid priority '${v.priority}'" if !contains(["regular", "spot"], lower(v.priority))])}. Priority must be either 'Regular' or 'Spot' (case-insensitive)."
   }
 
   validation {
-    condition = alltrue([
-      for k, v in var.node_pools :
-      lower(v.priority) != "spot" || contains(["delete", "deallocate"], lower(v.eviction_policy))
-    ])
-    error_message = "When priority is 'Spot', eviction_policy must be either 'Delete' or 'Deallocate' (case-insensitive)."
+    condition = length([
+      for k, v in var.node_pools : k
+      if lower(v.priority) == "spot" && !contains(["delete", "deallocate"], lower(v.eviction_policy))
+    ]) == 0
+    error_message = "Invalid eviction_policy values found. ${join(", ", [for k, v in var.node_pools : "Node pool '${k}' has invalid eviction_policy '${v.eviction_policy}'" if lower(v.priority) == "spot" && !contains(["delete", "deallocate"], lower(v.eviction_policy))])}. When priority is 'Spot', eviction_policy must be either 'Delete' or 'Deallocate' (case-insensitive)."
   }
 
   validation {
-    condition = alltrue([
-      for k, v in var.node_pools : v.spot_max_price >= -1
-    ])
-    error_message = "Each node pool's spot_max_price must be greater than or equal to -1."
+    condition = length([
+      for k, v in var.node_pools : k
+      if !(v.spot_max_price == -1 || v.spot_max_price >= 0)
+    ]) == 0
+    error_message = "Invalid spot_max_price values found. ${join(", ", [for k, v in var.node_pools : "Node pool '${k}' has invalid spot_max_price '${v.spot_max_price}'" if !(v.spot_max_price == -1 || v.spot_max_price >= 0)])}. The spot_max_price must be either -1 (market price) or >= 0."
   }
 }