Simple generic scheduler job to execute a Groovy script

Long time ago, my client asked me if it is possible to execute a groovy updater script at midnight. I said it's not supported yet. So, someone did that manually at midnight.
So, I'm wondering now how we can support a scheduled task to execute a groovy updater script.

One of the simplest solutions could be:

• Add a generic scheduler job class: UpdaterExecutingJob.java.
• An end project can configure a scheduler job with parameters specifying which updater script to execute like the following example:

/hippo:configuration/hippo:modules/scheduler/hippo:moduleconfig/system/demoUpdaterExecutor:
  jcr:primaryType: hipposched:repositoryjob
  hipposched:attributeNames: [updatername]
  hipposched:attributeValues: [DemoUpdater]
  hipposched:enabled: true
  hipposched:repositoryJobClass: org.onehippo.forge...UpdaterExecutingJob
  /hipposched:triggers:
    jcr:primaryType: hipposched:triggers
    /nightly:
      jcr:primaryType: hipposched:crontrigger
      jcr:mixinTypes: ['hippo:lockable', 'mix:lockable']
      hipposched:cronExpression: 0 0 3 * * ?
      hipposched:enabled: true

Then the generic scheduler job will push the configured updater, DemoUpdater in this case, to the updater queue, based on trigger configuration.
They can optionally choose to use a simple trigger instead of cron trigger if they want to run it only once at a time.
I think this will be very useful in many projects.