Access to Python, PHP, MySQL for students

[mavhc]

Indeed, ask the customer what they are trying to achieve, ask to see the specs, lesson plans etc so you don't miss something if you suspect they're being vague

[timbo343]

Simpler the better in this case. At least we noa know that it can all be dont witbout a database. Will let the teacher figure this one out - it's the first time this has been run in the school. Edited October 10, 2019 by timbo343

[WhiteStar1]

@Nausing did you get anywhere with this?

 

To the group. We are in the same situation as the OP and i don't want to have python on the desktop machines. Having the VHD on the local machine would be the easiest option however if the machine needs to be re-imaged then it takes down the VHD with it. Maybe having the VHDs on a NAS or a file share would possibly be the next option however there is no budget for a NAS.

 

Running VMs on a HOST is out the question too as we don't have the resources or hardware to run 30+ VMs at a time for a lesson.

 

At my school we running RM CC4. We use the RM Oracle VirtualBox blueprint (I know it proved easier to use than setting it up manual). The VM software is deployed with the computer image for the client machines. Using the blueprint, set the student share as drive N in the VM. This allows the student to save any work to their share within the VM. We only allow oneway - write to N drive. Off course as noted in this thread - no nics, no changes to the image and loads clean on every boot. This works for the ICT department. Also the deployment is less than a MB but the actual deployment of the VHD is from a share off the server. Got Windows 7 down to 30GB, deployment outside hours is bearable. Got the staff always asking for changes so modifing the VHD is easy on the share and then redeploy (which is a pain!). Windows 7 with MS Virtual Studio proved to be a right hog - 60GB to get all the modules required along with MS database. Current VHD only has Python and Windows 7 and a few other little programs.

[jthompson]

I reckon you ought to be able to get your Win7+python VHD much smaller than 30GB. Ours turned out at around 8GB.

[mavhc]

Windows 10 has containers, probably better.

 

Remember Virtual Box extensions are only for personal use or for use in the education curriculum. And Oracle is mostly lawyers with lots of free time.

[dmj]

some rather elaborate solutions to prevent the operating system for crashing!

It probably shows my age, but this problem was solved decades ago and is still heavily used with *nix multiuser systems: simply create a short script that starts the application (python) and changes it's priority to a lower one than default (use renice on linux/mac google will tell you how to do this in powershell).

As @mavhc suggests a container is a good idea, but this will only help with python versions and isolation - it won't protect the operating system kernel from being drowned - containers still run on the system kernel; you would need to combine both approaches.

[mavhc]

Stopping people from overloading their own machines is a waste of time, it's impossible, and if they really want to try to break the computer they can power it off and on at the switch 100 times. Some idiot kid will run the code once, ban them from computers for a week, done.

[dmj]

^ yeah, we do have a habit of over complicating things, but I think the renice is a very simple and elegant solution compared to running and entire VM! Plus you don't need to get your hands dirty with banning people.

[jthompson]

Showing my ignorance here, but if python is running at a lower priority, would that prevent 1000000 instances of notepad.exe spawned from a python script (slight exaggeration) from impacting the OS performance?

 

Yes, kids will be able to turn the mains on and off, but we've found that when the host OS isn't being brought to a grinding halt for laughs, they tend not to do that.

 

As for addressing such problems by falling back on the behaviour policy: that wasn't anything like as effective as deploying the stuff in a VM, which killed the problems overnight. That's just how it went down here. They may still be running their daft scripts, but that's between teacher and pupil. I'm not needing to be drawn into doing police work.

[dmj]

Showing my ignorance here, but if python is running at a lower priority, would that prevent 1000000 instances of notepad.exe spawned from a python script (slight exaggeration) from impacting the OS performance?

.

 

That would occur if you allow python access to operating system tasks which @mavhc suggestion of containers would prevent (or remove python os)

ideally you would set the nicenesss limit per user or group. This is defined in /etc/security/limits.conf. Again, I can't describe the way to do this in windows - but I'm sure it is possible.

[mavhc]

You'd have to limit ram and disk too.

 

My solution as a teacher: Ah, something interesting has happened here, everyone have a look at X's screen, what's the bug in their code? And how could you fix it, you know, apart from by not being an idiot?

[jthompson]

You'd have to limit ram and disk too.

 

My solution as a teacher: Ah, something interesting has happened here, everyone have a look at X's screen, what's the bug in their code? And how could you fix it, you know, apart from by not being an idiot?

 

True enough, but a VM doesn't preclude this.