feat: add master_instance_name and instance_type to mysql module (#556)

modules/mysql/README.md

@@ -36,10 +36,12 @@ Note: CloudSQL provides [disk autoresize](https://cloud.google.com/sql/docs/mysq
 | follow\_gae\_application | A Google App Engine application whose zone to remain in. Must be in the same region as this instance. | `string` | `null` | no |
 | iam\_users | A list of IAM users to be created in your CloudSQL instance | <pre>list(object({<br>    id    = string,<br>    email = string<br>  }))</pre> | `[]` | no |
 | insights\_config | The insights\_config settings for the database. | <pre>object({<br>    query_plans_per_minute  = number<br>    query_string_length     = number<br>    record_application_tags = bool<br>    record_client_address   = bool<br>  })</pre> | `null` | no |
+| instance\_type | Users can upgrade a read replica instance to a stand-alone Cloud SQL instance with the help of instance\_type. To promote, users have to set the instance\_type property as CLOUD\_SQL\_INSTANCE and remove/unset master\_instance\_name and replica\_configuration from instance configuration. This operation might cause your instance to restart. | `string` | `null` | no |
 | ip\_configuration | The ip\_configuration settings subblock | <pre>object({<br>    authorized_networks                           = optional(list(map(string)), [])<br>    ipv4_enabled                                  = optional(bool, true)<br>    private_network                               = optional(string)<br>    require_ssl                                   = optional(bool)<br>    allocated_ip_range                            = optional(string)<br>    enable_private_path_for_google_cloud_services = optional(bool, false)<br>    psc_enabled                                   = optional(bool, false)<br>    psc_allowed_consumer_projects                 = optional(list(string), [])<br>  })</pre> | `{}` | no |
 | maintenance\_window\_day | The day of week (1-7) for the master instance maintenance. | `number` | `1` | no |
 | maintenance\_window\_hour | The hour of day (0-23) maintenance window for the master instance maintenance. | `number` | `23` | no |
 | maintenance\_window\_update\_track | The update track of maintenance window for the master instance maintenance. Can be either `canary` or `stable`. | `string` | `"canary"` | no |
+| master\_instance\_name | The name of the existing instance that will act as the master in the replication setup. | `string` | `null` | no |
 | module\_depends\_on | List of modules or resources this module depends on. | `list(any)` | `[]` | no |
 | name | The name of the Cloud SQL resources | `string` | n/a | yes |
 | password\_validation\_policy\_config | The password validation policy settings for the database instance. | <pre>object({<br>    enable_password_policy      = bool<br>    min_length                  = number<br>    complexity                  = string<br>    disallow_username_substring = bool<br>  })</pre> | `null` | no |

modules/mysql/main.tf

@@ -50,14 +50,16 @@ resource "random_id" "suffix" {
 }
 
 resource "google_sql_database_instance" "default" {
-  provider            = google-beta
-  project             = var.project_id
-  name                = local.master_instance_name
-  database_version    = var.database_version
-  region              = var.region
-  encryption_key_name = var.encryption_key_name
-  deletion_protection = var.deletion_protection
-  root_password       = var.root_password != "" ? var.root_password : null
+  provider             = google-beta
+  project              = var.project_id
+  name                 = local.master_instance_name
+  database_version     = var.database_version
+  region               = var.region
+  master_instance_name = var.master_instance_name
+  instance_type        = var.instance_type
+  encryption_key_name  = var.encryption_key_name
+  deletion_protection  = var.deletion_protection
+  root_password        = var.root_password != "" ? var.root_password : null
 
   settings {
     tier                        = var.tier
@@ -173,10 +175,15 @@ resource "google_sql_database_instance" "default" {
       }
     }
 
-    maintenance_window {
-      day          = var.maintenance_window_day
-      hour         = var.maintenance_window_hour
-      update_track = var.maintenance_window_update_track
+    // Maintenance windows cannot be set for read replicas: https://cloud.google.com/sql/docs/mysql/instance-settings#maintenance-window-2ndgen
+    dynamic "maintenance_window" {
+      for_each = var.master_instance_name != null ? [] : ["true"]
+
+      content {
+        day          = var.maintenance_window_day
+        hour         = var.maintenance_window_hour
+        update_track = var.maintenance_window_update_track
+      }
     }
   }
 

modules/mysql/metadata.yaml

@@ -199,6 +199,9 @@ spec:
           id    = string
           email = string
         }))
+  - name: instance_type
+    description: Users can upgrade a read replica instance to a stand-alone Cloud SQL instance with the help of instance_type. To promote, users have to set the instance_type property as CLOUD_SQL_INSTANCE and remove/unset master_instance_name and replica_configuration from instance configuration. This operation might cause your instance to restart.
+    type: string
   - name: ip_configuration
     description: The ip_configuration settings subblock
     type: |-
@@ -229,6 +232,9 @@ spec:
     description: The update track of maintenance window for the master instance maintenance. Can be either `canary` or `stable`.
     type: string
     default: canary
+  - name: master_instance_name
+    description: (Optional) The name of the existing instance that will act as the master in the replication setup. Note, this requires the master to have `binary_log_enabled` set, as well as existing backups.
+    type: string
   - name: module_depends_on
     description: List of modules or resources this module depends on.
     type: list(any)

modules/mysql/variables.tf

@@ -49,6 +49,20 @@ variable "region" {
   default     = "us-central1"
 }
 
+// optional
+variable "master_instance_name" {
+  description = "The name of the existing instance that will act as the master in the replication setup."
+  type        = string
+  default     = null
+}
+
+// optional
+variable "instance_type" {
+  description = "Users can upgrade a read replica instance to a stand-alone Cloud SQL instance with the help of instance_type. To promote, users have to set the instance_type property as CLOUD_SQL_INSTANCE and remove/unset master_instance_name and replica_configuration from instance configuration. This operation might cause your instance to restart."
+  type        = string
+  default     = null
+}
+
 // Master
 variable "tier" {
   description = "The tier for the master instance."