feat(mwaa): add worker_replacement_strategy variable

Add support for configuring the worker replacement strategy when
updating MWAA environments. This allows users to choose between
FORCED (immediate replacement) and GRACEFUL (wait up to 12 hours
for tasks to complete) strategies.

- Add worker_replacement_strategy variable to root module
- Add worker_replacement_strategy to complete example
- Default to null in root module to preserve existing behavior

Author: RoseSecurity

examples/complete/fixtures.us-east-2.tfvars

@@ -22,6 +22,8 @@ min_workers = 1
 
 max_workers = 10
 
+worker_replacement_strategy = "FORCED"
+
 webserver_access_mode = "PRIVATE_ONLY"
 
 dag_processing_logs_enabled = true

examples/complete/main.tf

@@ -32,6 +32,7 @@ module "mwaa" {
   environment_class             = var.environment_class
   min_workers                   = var.min_workers
   max_workers                   = var.max_workers
+  worker_replacement_strategy   = var.worker_replacement_strategy
   webserver_access_mode         = var.webserver_access_mode
   dag_processing_logs_enabled   = var.dag_processing_logs_enabled
   dag_processing_logs_level     = var.dag_processing_logs_level

examples/complete/variables.tf

@@ -104,3 +104,15 @@ variable "min_workers" {
   description = "The minimum number of workers that you want to run in your environment."
   default     = 1
 }
+
+variable "worker_replacement_strategy" {
+  type        = string
+  description = "The worker replacement strategy to use when updating the environment. Valid values: `FORCED`, `GRACEFUL`. `FORCED` means Apache Airflow workers will be stopped and replaced without waiting for tasks to complete before an update. `GRACEFUL` means Apache Airflow workers will be able to complete running tasks for up to 12 hours during an update before being stopped and replaced."
+  default     = "FORCED"
+
+  validation {
+    condition     = contains(["FORCED", "GRACEFUL"], var.worker_replacement_strategy)
+    error_message = "Valid values are: `FORCED` or `GRACEFUL`."
+  }
+}
+

main.tf

@@ -223,6 +223,7 @@ resource "aws_mwaa_environment" "default" {
   kms_key                          = var.kms_key
   max_workers                      = var.max_workers
   min_workers                      = var.min_workers
+  worker_replacement_strategy      = var.worker_replacement_strategy
   min_webservers                   = var.environment_class == "mw1.micro" ? 1 : var.min_webservers
   max_webservers                   = var.environment_class == "mw1.micro" ? 1 : var.max_webservers
   schedulers                       = var.schedulers

variables.tf

@@ -81,6 +81,17 @@ variable "min_workers" {
   default     = 1
 }
 
+variable "worker_replacement_strategy" {
+  type        = string
+  description = "The worker replacement strategy to use when updating the environment. Valid values: `FORCED`, `GRACEFUL`. `FORCED` means Apache Airflow workers will be stopped and replaced without waiting for tasks to complete before an update. `GRACEFUL` means Apache Airflow workers will be able to complete running tasks for up to 12 hours during an update before being stopped and replaced."
+  default     = null
+
+  validation {
+    condition     = var.worker_replacement_strategy == null || contains(["FORCED", "GRACEFUL"], var.worker_replacement_strategy)
+    error_message = "Valid values are: `FORCED`, `GRACEFUL`, or `null`."
+  }
+}
+
 variable "max_webservers" {
   type        = number
   description = "The maximum number of web servers that you want to run in your environment."