Allow use of provider region, with big caveats in docs. (#1463)

Author: nat-henderson

google/resource_sql_database_instance.go

@@ -51,7 +51,7 @@ func resourceSqlDatabaseInstance() *schema.Resource {
 		Schema: map[string]*schema.Schema{
 			"region": &schema.Schema{
 				Type:     schema.TypeString,
-				Required: true,
+				Optional: true,
 				ForceNew: true,
 			},
 
@@ -423,7 +423,10 @@ func resourceSqlDatabaseInstanceCreate(d *schema.ResourceData, meta interface{})
 		return err
 	}
 
-	region := d.Get("region").(string)
+	region, err := getRegion(d, config)
+	if err != nil {
+		return err
+	}
 	databaseVersion := d.Get("database_version").(string)
 
 	_settingsList := d.Get("settings").([]interface{})

website/docs/r/sql_database_instance.html.markdown

@@ -59,6 +59,10 @@ The following arguments are supported:
 * `region` - (Required) The region the instance will sit in. Note, first-generation Cloud SQL instance
     regions do not line up with the Google Compute Engine (GCE) regions, and Cloud SQL is not
     available in all regions - choose from one of the options listed [here](https://cloud.google.com/sql/docs/mysql/instance-locations).
+    A valid region must be provided to use this resource. If a region is not provided in the resource definition,
+    the provider region will be used instead, but this will be an apply-time error for all first-generation
+    instances *and* for second-generation instances if the provider region is not supported with Cloud SQL.
+    If you choose not to provide the `region` argument for this resource, make sure you understand this.
 
 * `settings` - (Required) The settings to use for the database. The
     configuration is detailed below.