Sql database add deletion policy (GoogleCloudPlatform#6821)

* feat: adding deletion_policy=abandon to google_sql_database resource

* feat: honing in on correct behavior of google_sql_database

* feat: got tests to pass

* fix: simplified adding deletion_policy to google_sql_database

* chore: switch deletion_policy to virtual field

mmv1/products/sql/terraform.yaml

@@ -36,12 +36,34 @@ overrides: !ruby/object:Overrides::ResourceOverrides
           deletion_protection: "false"
         oics_vars_overrides:
           deletion_protection: "false"
+      - !ruby/object:Provider::Terraform::Examples
+        name: "sql_database_deletion_policy"
+        primary_resource_id: "database_deletion_policy"
+        vars:
+          database_name: "my-database"
+          database_instance_name: "my-database-instance"
+          deletion_protection: "true"
+        test_vars_overrides:
+          deletion_protection: "false"
+        oics_vars_overrides:
+          deletion_protection: "false"
     properties:
       collation: !ruby/object:Overrides::Terraform::PropertyOverride
         default_from_api: true
       charset: !ruby/object:Overrides::Terraform::PropertyOverride
         default_from_api: true
         diff_suppress_func: 'caseDiffSuppress'
+    virtual_fields:
+      - !ruby/object:Api::Type::String
+        name: 'deletion_policy'
+        description: |
+          The deletion policy for the database. Setting ABANDON allows the resource 
+          to be abandoned rather than deleted. This is useful for Postgres, where databases cannot be 
+          deleted from the API if there are users other than cloudsqlsuperuser with access. Possible 
+          values are: "ABANDON".
+        default_value: "ABANDON"
+    custom_code: !ruby/object:Provider::Terraform::CustomCode
+      pre_delete: templates/terraform/pre_delete/sql_database_deletion_policy.erb
   SourceRepresentationInstance: !ruby/object:Overrides::Terraform::ResourceOverride
     examples:
       - !ruby/object:Provider::Terraform::Examples

mmv1/templates/terraform/examples/sql_database_deletion_policy.tf.erb

@@ -0,0 +1,19 @@
+# [START cloud_sql_database_create]
+resource "google_sql_database" "<%= ctx[:primary_resource_id] %>" {
+  name     = "<%= ctx[:vars]['database_name'] %>"
+  instance = google_sql_database_instance.instance.name
+  deletion_policy = "ABANDON"
+}
+# [END cloud_sql_database_create]
+
+# See versions at https://registry.terraform.io/providers/hashicorp/google/latest/docs/resources/sql_database_instance#database_version
+resource "google_sql_database_instance" "instance" {
+  name             = "<%= ctx[:vars]['database_instance_name'] %>"
+  region           = "us-central1"
+  database_version = "POSTGRES_14"
+  settings {
+    tier = "db-g1-small"
+  }
+
+  deletion_protection  = "<%= ctx[:vars]['deletion_protection'] %>"
+}

mmv1/templates/terraform/pre_delete/sql_database_deletion_policy.erb

@@ -0,0 +1,5 @@
+if deletionPolicy := d.Get("deletion_policy"); deletionPolicy == "ABANDON" {
+    // Allows for database to be abandoned without deletion to avoid deletion failing
+    // for Postgres databases in some circumstances due to existing SQL users
+    return nil
+}