Migrations

When using the <version/> tag in the model xml you automatically allow upgrades of your configuration data. If the tag is missing, it will automatically assume your at version 0.0.0 (initial version).

The migration feature provides a pluggable framework to offer new and changed attributes after installation of new software and is therefor automatically triggered when performing upgrades or installing packages.

Tip

You can always trigger migrations manually by executing /usr/local/opnsense/mvc/script/run_migrations.php from a console. This will output all installed modules and the upgrades performed.

If no overrides are provided and the module version of the running configuration doesn’t equal the one installed, there automatically will be a migration created using the BaseModelMigration base class. This will take care of basic changes, such as adding new fields and applying defaults.

Note

The current version will always be saved as an attirbute on the model xml (e.g. <Alias version="1.0.0">)

Custom migrations

In some cases one wants to perform custom actions when upgrading between version, such as gathering data from legacy configuration settings.

The directory Migrations in the model directory is used to hold the migration code on a per version basis. By default classes (and files) in there use the following naming scheme: M1_0_0 which stands for [M]igration version [1.0.0].

Note

If different models share a namespace, you can change the prefix of the migration files, when nothing is provided the default is M, the tag <migration_prefix/> can be used to change this to something else. (e.g. <migration_prefix>MFP</migration_prefix>)

The boilerplate for a model migration looks like this (for a migration to 1.0.0):

class M1_0_0 extends BaseModelMigration
{
    /**
     * default model migration
     * @param $model
     */
    public function run($model)
    {
        parent::run($model);
    }

    /**
     * post migration action, run after config sync
     * @param $model
     */
    public function post($model)
    {
        return;
    }
}

It contains two methods, run() and post(). The first one is executed in memory, before serializing data back to the running configuration and for all version steps in sequence. (an upgrade from 1.0.0 to 1.0.2 might execute 1.0.1, 1.0.2, 1.0.3). The configuration data itself will be synced ones in this case.

The post action is called after normal model configuration and can sometimes be practical to alter the raw model xml, for example if model versions require a move of datasets, without actually changing content.

Note

Although there are toggles in place, data migration can easily lead to race conditions. Always try to design your software for change, adding fields which pass validation by default for example is always preferred above situations which will fail by default.