Leo Catalinas - 2012-09-06

Hi all,

First of all, want to thank the webmin and usermin developers for the great job :-)

The question…

I have configured Usermin with the "Scheduled Cron Jobs" module, for a bussiness processes manager user (named 'procuser') and everything works fine. All bussiness processes are in its user crontab, and it is fairly good and easy for our users to manage them via web :-)

But the problem arises when more than one people login with the same user 'procuser' at same time: if multiple editions of the crontab "overlaps" (occurs at same time), only the last configuration saved gets really saved and the others are lost. In other words: the configuration gets corrupted.

This seems because webmin/usermin doesn't lock the crontab config files while edits them, or something similar. It would be the best solution, but I tried the Webmin "File Lock" module without success, and Usermin seems not have it.

The next and easiest solution could be to limit the max concurrent sessions or logins for the user 'procuser' to one, but I can't find the way to do this in webmin/usermin configuration.

So… Does somebody know how to…
  a) establish locks for the cron jobs edition, or…
  b) limit concurrent user logins to one?

Thank you very much in advance.