Tag: containers

Labtainers in a Web desktop through noVNC X11 proxy, full docker containers

Here’s another recording of a demo I’ve made of our efforts on running Labtainers with a Web desktop.

This time, we’re using a modified version of DoroWu’s noVNC X11 wrapper container (“docker-ubuntu-vnc-desktop“), to provide an X11 Display to labtainers.

I initially adapted DoroWu’s container image by using Debian instead of Ubuntu, but it appeared that noVNC 1.0.0 was a bit too old in the Debian package. So I switched back to the same version as the one DoroWu chose, and this time no more disconnections.

Also, we’re now rebuilding the Labtainer master container from upstream’s Git repo. Fresh Labs every day 😉

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Virtualized lab demonstration using a tweaked Labtainers running in a container

I’ve recorded a screencast: Labtainers in docker demonstration (embedded below) demonstrating how I’ve tweaked Labtainers so as to run it inside its own Docker container.

I’m currently very much excited by the Labtainers framework for delivering virtual labs, for instance in the context of MOOCs.

Labtainers is quite interesting as it allows isolating a lab in several containers running in their own dedicated virtual network, which helps distributing a lab without needing to install anything locally.

My tweak allows to run what I called the “master” container which contains the labtainers scripts, instead of having to install labtainers on a Linux host. This should help installation and distribution of labtainers, as well as deploying it on cloud platforms, some day soon. In the meantime Labtainer containers of the labs run with privileges so it’s advised to be careful, and running the whole of these containers in a VM may be safer. Maybe Labtainers will evolve in the future to integrate a containerization of its scripts. My patches are pending, but the upstream authors are currently focused on some other priorities.

Another interesting property of labtainers that is shown in the demo is the auto-grading feature that uses traces of what was performed inside the lab environment by the student, to evaluate the activities. Here, the telnetlab that I’ve shown, is evaluated by looking at text input on the command line or messages appearing on the stdout or in logs : the student launched both telnet or ssh, some failed login appeared, etc.

However, the demo is a bit confusing, in that I recorded a second lab execution whereas I had previously attempted a first try at the same telnetlab. In labtainers, traces of execution can accumulate : the student wil make a first attempt, and restart later, before sending it all to the professor (unless a redo.py is issued). This explanes that the  grading appears to give a different result than what I performed in the screencast.

Stay tuned for more news about my Labtainers adventures.

P.S. thanks to labtainers authors, and obs-studio folks for the screencast recording tool 🙂

A review of Virtual Labs virtualization solutions for MOOCs

I’ve just uploaded a new memo A review of Virtual Labs virtualization solutions for MOOCs in the form of a page on my blog, before I eventually publish something more elaborated (and valuated by peer review).

The subtitle is “From Virtual Machines running locally or on IaaS, to containers on a PaaS, up to hypothetical ports of tools to WebAssembly for serverless execution in the Web browser”

Excerpt from the intro :

In this memo, we try to draw an overview of some benefits and concerns with existing approaches at using virtualization techniques for running Virtual Labs, as distributions of tools made available for distant learners.

We describe 3 main technical architectures: (1) running Virtual Machine images locally on a virtual machine manager, or (2) displaying the remote execution of similar virtual machines on a IaaS cloud, and (3) the potential of connecting to the remote execution of minimized containers on a remote PaaS cloud.

We then elaborate on some perspectives for locally running ports of applications to the WebAssembly virtual machine of the modern Web browsers.

I hope this will be of some interest for some.

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