Azure-redeploy-fixes-upstream (#13058)

We've had to do a redeploy of our hail batch instance on Azure. This PR
resolves/clarifies two issues we encountered.

1) Storage Account Name Uniqueness

Due to Azure's restrictions on storage account naming (mainly that names
must be globally unique) the redeploy did not succeed.

This is because the resource group name (we chose to reuse hail) is
possible under a new subscription, but the generated storage account
names were therefore identical to our previous stack.

I've added in an argument called `storage_account_suffix` to account for
this issue. It can be set to any arbitrary string that complies with
Azure's storage account naming scheme in order to avoid naming conflicts
in the future.

While the option remains to simply choose a novel resource group name
this is not enforced by Azure and anyone deploying a stack similarly
named to someone else would not know until the `terraform apply` stage
that the name would not work.

2) Mysql Flexible Server Zones

The only other issue is that the zone argument for the mysql flexible
server is no longer always valid depending on your compute region. We
needed to comment it out for a successful deploy in Australia East.

The comment that has been added we hope will be helpful for others in
future.

infra/azure/main.tf

@@ -94,6 +94,7 @@ module "batch" {
   batch_test_user_storage_account_name = var.batch_test_user_storage_account_name
   resource_group        = data.azurerm_resource_group.rg
   container_registry_id = azurerm_container_registry.acr.id
+  storage_account_suffix = var.storage_account_suffix
 }
 
 module "global_config" {
@@ -132,4 +133,5 @@ module "ci" {
   github_context                          = var.ci_config.github_context
   ci_and_deploy_github_oauth_token        = var.ci_config.ci_and_deploy_github_oauth_token
   ci_test_repo_creator_github_oauth_token = var.ci_config.ci_test_repo_creator_github_oauth_token
+  storage_account_suffix                  = var.storage_account_suffix
 }

infra/azure/modules/batch/main.tf

@@ -50,7 +50,7 @@ resource "kubernetes_secret" "batch_worker_ssh_public_key" {
 }
 
 resource "azurerm_storage_account" "batch" {
-  name                     = "${var.resource_group.name}batch"
+  name                     = "${var.resource_group.name}batch${var.storage_account_suffix}"
   resource_group_name      = var.resource_group.name
   location                 = var.resource_group.location
   account_tier             = "Standard"
@@ -74,7 +74,7 @@ resource "azurerm_storage_container" "query" {
 }
 
 resource "azurerm_storage_account" "test" {
-  name                     = "${var.batch_test_user_storage_account_name}test"
+  name                     = "${var.batch_test_user_storage_account_name}test${var.storage_account_suffix}"
   resource_group_name      = var.resource_group.name
   location                 = var.resource_group.location
   account_tier             = "Standard"

infra/azure/modules/batch/variables.tf

@@ -13,3 +13,7 @@ variable batch_test_user_storage_account_name {
 variable container_registry_id {
   type = string
 }
+
+variable storage_account_suffix {
+  type = string
+}

infra/azure/modules/ci/main.tf

@@ -1,5 +1,5 @@
 resource "azurerm_storage_account" "ci" {
-  name                     = "${var.resource_group.name}ci"
+  name                     = "${var.resource_group.name}ci${var.storage_account_suffix}"
   resource_group_name      = var.resource_group.name
   location                 = var.resource_group.location
   account_tier             = "Standard"

infra/azure/modules/ci/variables.tf

@@ -36,3 +36,7 @@ variable "deploy_steps" {
 variable "github_context" {
   type = string
 }
+
+variable "storage_account_suffix" {
+  type = string
+}

infra/azure/modules/db/main.tf

@@ -36,6 +36,8 @@ resource "azurerm_mysql_flexible_server" "db" {
   # Which availability zone (out of 1,2,3) that the database should be hosted
   # in. This should ideally match the zone that batch is in but we don't have
   # availability zones enabled in AKS.
+  # Sometimes zones are not available in particular regions
+  # In this case either change to an appropriate zone or comment the below line out
   zone = 1
 
   delegated_subnet_id = var.subnet_id

infra/azure/variables.tf

@@ -59,3 +59,7 @@ variable oauth2_developer_redirect_uris {
   type    = list(string)
   default = []
 }
+
+variable storage_account_suffix {
+  type = string
+}