regional MySQL DBs - automatic backup conf

modules/cloudsql-instance/main.tf

@@ -18,10 +18,11 @@ locals {
   prefix       = var.prefix == null ? "" : "${var.prefix}-"
   is_mysql     = can(regex("^MYSQL", var.database_version))
   has_replicas = try(length(var.replicas) > 0, false)
+  is_regional  = var.availability_type == "REGIONAL" ? true : false
 
   // Enable backup if the user asks for it or if the user is deploying
-  // MySQL with replicas
-  enable_backup = var.backup_configuration.enabled || (local.is_mysql && local.has_replicas)
+  // MySQL in HA configuration (regional or with specified replicas)
+  enable_backup = var.backup_configuration.enabled || (local.is_mysql && local.has_replicas) || (local.is_mysql && local.is_regional)
 
   users = {
     for user, password in coalesce(var.users, {}) :
@@ -76,11 +77,11 @@ resource "google_sql_database_instance" "primary" {
       content {
         enabled = true
 
-        // enable binary log if the user asks for it or we have replicas,
+        // enable binary log if the user asks for it or we have replicas (default in regional),
         // but only for MySQL
         binary_log_enabled = (
           local.is_mysql
-          ? var.backup_configuration.binary_log_enabled || local.has_replicas
+          ? var.backup_configuration.binary_log_enabled || local.has_replicas || local.is_regional
           : null
         )
         start_time                     = var.backup_configuration.start_time

tests/modules/cloudsql_instance/test_plan.py

@@ -90,6 +90,17 @@ def test_mysql_replicas_enables_backup(plan_runner):
   assert backup_config['binary_log_enabled']
 
 
+def test_mysql_binary_log_for_regional(plan_runner):
+  "Test that the binary log will be enabled for regional MySQL DBs."
+
+  _, resources = plan_runner(database_version="MYSQL_8_0", availability_type="REGIONAL")
+  assert len(resources) == 1
+  primary = [r for r in resources if r['name'] == 'primary'][0]
+  backup_config = primary['values']['settings'][0]['backup_configuration'][0]
+  assert backup_config['enabled']
+  assert backup_config['binary_log_enabled']
+
+
 def test_users(plan_runner):
   "Test user creation."