Enhancement to exec

Is your feature request related to a problem? Please describe. We want to be able to create custom metrics by retrieving from a database the query performance data. Rather than invoking a separate script it would be cool if we could do it programmatically using Lua.

Additionally rather running the script on a delay process - it would be great if they could be set against a cron schedule.

Describe the solution you'd like Option to invoke a lua script rather than and external script.

Schedule the exec plugin against a cron style schedule

Describe alternatives you've considered

Options such as making the exec a 1 off process, that then schedules a cronjob. - this makes for a very messy deployment, and risks duplication or worse the process failing to run such that Fluent Bit doesn't pickup the content.

An alternative is that we can trigger a processor, therefore the execution becomes stubbed out

Additional context

We're looking at Fluent Bit as part of a possible capability around Oracle database management rather than a commercial option which provide details such as SQL performance. This information can be retrieved by running SQL queries. Having Lua means we can use it to script the credentials capture and connection logic.