feat: Add support for allowed_instance_types on self-managed nodegroup ASG (#2757)

Co-authored-by: Bryant Biggs <bryantbiggs@gmail.com>

examples/self_managed_node_group/main.tf

@@ -216,6 +216,58 @@ module "eks" {
         }
       }
 
+      instance_attributes = {
+        name = "instance-attributes"
+
+        min_size     = 1
+        max_size     = 2
+        desired_size = 1
+
+        bootstrap_extra_args = "--kubelet-extra-args '--node-labels=node.kubernetes.io/lifecycle=spot'"
+
+        instance_type = null
+
+        # launch template configuration
+        instance_requirements = {
+          cpu_manufacturers                           = ["intel"]
+          instance_generations                        = ["current", "previous"]
+          spot_max_price_percentage_over_lowest_price = 100
+
+          vcpu_count = {
+            min = 1
+          }
+
+          allowed_instance_types = ["t*", "m*"]
+        }
+
+        use_mixed_instances_policy = true
+        mixed_instances_policy = {
+          instances_distribution = {
+            on_demand_base_capacity                  = 0
+            on_demand_percentage_above_base_capacity = 0
+            on_demand_allocation_strategy            = "lowest-price"
+            spot_allocation_strategy                 = "price-capacity-optimized"
+          }
+
+          # ASG configuration
+          override = [
+            {
+              instance_requirements = {
+                cpu_manufacturers                           = ["intel"]
+                instance_generations                        = ["current", "previous"]
+                spot_max_price_percentage_over_lowest_price = 100
+
+                vcpu_count = {
+                  min = 1
+                }
+
+                allowed_instance_types = ["t*", "m*"]
+              }
+            }
+          ]
+        }
+      }
+
       metadata_options = {
         http_endpoint               = "enabled"
         http_tokens                 = "required"