variable validation add

exercises/variables.tf.validation

@@ -0,0 +1,55 @@
+##############################################################################
+# Variables File
+#
+# Here is where we store the default values for all the variables used in our
+# Terraform code. If you create a variable with no default, the user will be
+# prompted to enter it (or define it via config file or command line flags.)
+
+variable "prefix" {
+  description = "This prefix will be included in the name of most resources."
+}
+
+variable "region" {
+  description = "The region where the resources are created."
+  default     = "us-east-1"
+
+  validation {
+    condition     = contains(["us-east-1", "us-west-1", "eu-west-2", "p-southeast-1"], var.region)
+    error_message = "region 변수는 us-east-1, us-west-1, eu-west-2, p-southeast-1 중 하나여야 합니다."
+  }
+}
+
+variable "address_space" {
+  description = "The address space that is used by the virtual network. You can supply more than one address space. Changing this forces a new resource to be created."
+  default     = "10.0.0.0/16"
+}
+
+variable "subnet_prefix" {
+  description = "The address prefix to use for the subnet."
+  default     = "10.0.10.0/24"
+}
+
+variable "instance_type" {
+  description = "Specifies the AWS instance type."
+  default     = "t2.micro"
+}
+
+variable "admin_username" {
+  description = "Administrator user name for mysql"
+  default     = "hashicorp"
+}
+
+variable "height" {
+  default     = "400"
+  description = "Image height in pixels."
+}
+
+variable "width" {
+  default     = "600"
+  description = "Image width in pixels."
+}
+
+variable "placeholder" {
+  default     = "placekitten.com"
+  description = "Image-as-a-service URL. Some other fun ones to try are fillmurray.com, placecage.com, placebeard.it, loremflickr.com, baconmockup.com, placeimg.com, placebear.com, placeskull.com, stevensegallery.com, placedog.net"
+}

variables.tf

@@ -11,7 +11,7 @@ variable "prefix" {
 
 variable "region" {
   description = "The region where the resources are created."
-  default     = "ap-northeast-1"
+  default     = "us-east-1"
 }
 
 variable "address_space" {