feat: add variable for availability domain (#16)

README.md

@@ -22,6 +22,7 @@ To help get started quickly with this Terraform module, I have included an examp
 
 | Name | Description | Type | Default | Required |
 |------|-------------|------|---------|:--------:|
+| <a name="input_availability_domain"></a> [availability\_domain](#input\_availability\_domain) | The availability domain in which the instance should be created, e.g Uocm:PHX-AD-1. | `string` | n/a | yes |
 | <a name="input_fingerprint"></a> [fingerprint](#input\_fingerprint) | The fingerprint of the private\_key, e.g. 8c:bf:17:7b:5f:e0:7d:13:75:11:d6:39:0d:e2:84:74. | `string` | n/a | yes |
 | <a name="input_private_key"></a> [private\_key](#input\_private\_key) | The private key retrieved from the Oracle account. | `string` | n/a | yes |
 | <a name="input_region"></a> [region](#input\_region) | The desired region of the cluster, e.g. us-phoenix-1. | `string` | n/a | yes |

compute.tf

@@ -1,6 +1,6 @@
 resource "oci_core_instance" "ubuntu_instance" {
   count               = var.instance_count
-  availability_domain = data.oci_identity_availability_domains.ads.availability_domains[0].name
+  availability_domain = coalesce(var.availability_domain, data.oci_identity_availability_domains.ads.availability_domains[0].name)
   compartment_id      = oci_identity_compartment.terraform_compartment.id
   shape               = var.instance_shape
 

variables.tf

@@ -23,6 +23,11 @@ variable "region" {
   type        = string
 }
 
+variable "availability_domain" {
+  description = "The availability domain in which the instance should be created, e.g Uocm:PHX-AD-1."
+  type = string
+}
+
 variable "ssh_public_key" {
   description = "The public key used for SSH to the instances."
   type        = string