Add support for external logging configuration

[malthe]

Enhancement

Currently, the Log4J configuration is hardcoded using a code-based static template.

This is not ideal because of the limited configuration options as seen in the documentation on managing audit logs:

StarRocks stores its audit logs in the local file fe/log/fe.audit.log rather than an internal database. The plugin AuditLoader allows you to manage audit logs directly within your cluster. Once installed, AuditLoader reads logs from the file, and loads them into StarRocks via HTTP PUT. You can then query the audit logs in StarRocks using SQL statements.

For example, for audit logs, rather than writing to a local file and reingest that into the database, we sometimes want to use other plugins or instrumentation such as OpenTelemetry.

It should be possible to specify a file-based configuration instead.

[kevincai]

@malthe will you be willing to contribute on this?

[malthe]

@kevincai will try to find time to do so.

[kevincai]

@kevincai will try to find time to do so.

@malthe thanks, please let me know if you need any help.