PROGRAM task whitelist

[artemzhdev]

Is your feature request related to a problem? Please describe.
I have pg_timetable running on linux. My chains and task definitions are taken from postgres database.
Currently for security reasons I have parameter "--no-program-tasks" defined in my service.
But I want to allow running of a single specific sh script. Unfortunately I can only allow all or nothing.
If I disable --no-program-tasks it brings a vulnerability - if somebody gets access to my postgres database then it's possible to run any script on behalf of my pg_timetable linux user. It's not sudo, but still not appreciated.

Describe the solution you'd like
Would be nice to have a whitelist of allowed commands. It can be either optional parameter --program-task-whitelist or PGTT_PROGRAM_TASK_WHITELIST environment variable (or some other meaningful name).

[pashagolub]

You could run another pg_timetable instance which will have only access to the script.