Portal-side Janitor background task

[natacha-beck]

For repetitive administrative tasks, we need a control panel
for launching and managing a background 'janitor' task on
the portal side. Responsabilities:

• Restart bourreaux after they fail, up to n times in x minutes
• Trigger 'clear caches' operations for files not used in x days
• Move userfiles to the archive disk if they've not been used in n days
• Archive CbrainTasks when they are old (need archiving system for tasks first, see issue Small view changes. #1212)
• Lock user accounts that are no longer used
• Check or probe DataProvider SSH tunnels (needed: API for that)
• Notify sysadmins in real time about situations using email, twitter, etc.
  • Disk filled
  • Bourreau down
  • Internal error messages
  • User feedback received

Related: 1212, 1751, 1627 || #38 , 2086 || #39 , 2174 || #41 , 3128, 4987 || #42

[prioux]

Other feature: when batch-processing records of a particular type, highlight the rows of the affected record in the index page. Suggested in #297

[prioux]

Maybe we can use the Raisl framework ActiveJobs :

http://guides.rubyonrails.org/active_job_basics.html

[prioux]

See also pre-requisite task #613

[natacha-beck]

@bryancaron and @prioux I think we should re-evaluate all issues related to Janitor since we have the BAC system now.

[prioux]

Closing: BackgroundActivity framework of 2024 handles most of this. Some of the suggested other uses (like closing accounts) could be implemented later easily.