Monitor Folder For New SubFolder / Execute Script Or Cron Job

[Mirfster]

Sorry if this was already answered elsewhere (was having no luck with search results urls working this morning)

I'm testing out setting quotas on User Home Directories and figure that I can easily set them with something like:

Code:

zfs set userquota@"Domain\User"=50G Data/Users

Only thing is that I am not making a User's Home folder the normal way. While there will be a DataStore and Share for "Users"; it is simply a Folder created via Windows Explorer that I will set the initial rights on (FreeNAS is also the Domain Controller here).

Rights aside, I could simply putty into FreeNAS and execute the command personally. But, I will not be the only person administering this and would prefer more of an automated method.

So, is there a simple way of monitoring "Data\Users" for a new SubFolder (only 1 level deep mind you) and execute a script (perhaps something like 'OnEvent' even)?

• I know that I could simply setup a Cron Job to run often, but wanted a more intelligent solution
• Wanting this to reside on FreeNAS itself and not another box (like Windows with a PowerShell Script)

Thanks in advance and if I am overlooking a simple solution, please feel free to hit me over the head with a keyboard. :)

P.S. Running FreeNAS 9.10

 

[sretalla]

Perhaps you can look at the devel/libinotify port/pkg to see how you would use it to get notified of changes to files/dirs. https://www.freshports.org/devel/libinotify

I also noticed there's a freebsd daemon available on github https://github.com/faelys/filewatcherd that seems to claim to be what you're asking for... I'm not 100% clear if it can watch for dirs alone or if it can only watch for files, but seems like what you want if you can rely on a file being there (or if you're better than me at reading the instructions, for empty dirs).

 

[sretalla]

If one of the above doesn't work out, it seems that fswatch would do the job:
https://github.com/emcrisostomo/fswatch

 

[Mirfster]

Thanks for the suggestions, will look into them. Not really liking the idea of adding things to FreeNAS though. Would rather something not so invasive. ;)

 

[sretalla]

Well, you would install it in a jail, so not really invasive in that sense...

I see that the work is all based on kqueue/kevent native functionality, but I suspect those are harder to use directly, hence the additional tools.

 

[Arwen]

I too wanted something that triggered a FreeNAS command. In my case, when my Rsync backups are done, I snapshot the backup dataset on my NAS with the current date. That way, each individual backup only takes as much space as what changed. A poor elf's de-duplication, since it does not span clients which may have the same exact files.

At present it's a manual step after my backups. But, I guess I will write a cron job to do the work...

 

[Mirfster]

I am pondering the idea of simply automating the creation of a file named something weird (like "OkayTimeToDoThatCronJob"); then have a cron job that runs every X minutes to look for that file. If it that file exists then it will do what I want and delete the file initially created...

Not my best idea but leaning towards that for now.

 

[Arwen]

I am pondering the idea of simply automating the creation of a file named something weird (like "OkayTimeToDoThatCronJob"); then have a cron job that runs every X minutes to look for that file. If it that file exists then it will do what I want and delete the file initially created...

Not my best idea but leaning towards that for now.

Basically what I will probahly do.

Don't forget to remove the file "OkayTimeToDoThatCronJob" at the beginning of the cronjob. If the task takes longer than the cronjob interval, (like 1 minute), then another instance of the task will be launched if the file still exists. As a former professional programmer, that's something I think of, (fault tolerance).

 

[Mirfster]

Good point on removal of file at initialization.