Skip to content
Demos for Look Ma, no OS!
PHP JavaScript CSS HTML Makefile Shell
Branch: master
Clone or download
Fetching latest commit…
Cannot retrieve the latest commit at this time.
Type Name Latest commit message Commit time
Failed to load latest commit information.

Look Ma, no OS! Interactive Demo

This repository contains the demo material for my talk entitled:

Look Ma, no OS! Unikernels and Their Applications

The slides can be found here:

There 4 very simple demos:

  • MirageOS (with Jitsu)
  • Rumprun
  • Runtime JS
  • LING

Initial setup

These demos are based on Vagrant. They should work with both VMware Fusion 7 and VirtualBox (even on Windows!). The only real prereq is to have Vagrant installed. If you would like to mount the directory as a shared NFS mount in the VM just enable NFS on your system and uncomment the shared folder line.

Once you have Vagrant + NFS installed run the following command to bring up the machine and SSH to it (X11 fowarding is enabled):

vagrant up
vagrant ssh

Note: VirtualBox is dog slow at this point in time. All of the instructions clone the repos to the local filesystem within the virtual machine, but even still when running in VirtualBox please have patience. If it's too slow then just purchase VMware Fusion. You won't regret that move if you are a frequent Vagrant user as it is much smoother and quicker.


The first and coolest demo is of a static site running on MirageOS; summoned just in time. The way it works is that we compile and package our unikernel as a Xen VM. Then we will fire up a DNS daemon based on Jitsu ( The way Jitsu works is:

  • A user attempts to resolve a domain against the daemon (
  • Jitsu checks Xen to see if the configured unikernel is running
  • If it is running, the daemon returns the A record and updates its TTL on the unikernel
  • If it is not running, the daemon will start the unikernel and then return the A record
  • After 2x the configured TTL for the A record passes, the unikernel is suspended (or deleted in our example)
  • Times for the initial request are about .5 seconds which includes recieving the DNS request, starting the unikernel, and responding with a record
  • Subsequent requests take approximate .02 seconds as the unikernel is already running

The site it is serving is based on the output of Jekyll ( We just take those static files and bundle them up with an OCaml based webserver in order to serve the static assets. In order to get this demo running, please follow these steps:

# Running from the shared directory is slow on VMware and
# terrible on VirtualBox so we'll clone it to the local fs.
git clone
cd lookma/mirageos/scripts

# Prepare the system

# Activate Opam
eval `opam config env`

# Build our unikernel

# Start the Jitsu DNS server

# Show that there are no VMs running
sudo xl list

# Test it out (in another terminal)!
dig @ 
sudo xl list

# Browse to the site
open # Not Jitsu
# or


In order to demonstrate the Rumprun unikernel, we will stand up a very basic WordPress stack. This involves:

  • Preparing the system
  • Building and starting the MySQL unikernel
  • Building and starting the PHP unikernel
  • Building and starting the NGINX unikernel
  • Running through the WordPress install

Note: MySQL is not tuned and is very, very slow at this time. I beleive this is just our implementation. Even though the install times out, it does actually complete and the site will load afterwards.

In order to get this demo going, please perform the following steps:

# Running from the shared directory is slow on VMware and
# terrible on VirtualBox so we'll clone it to the local fs.
git clone
cd lookma/rumpkernel/scripts

# Fire up MySQL

# Fire up PHP

# Fire up NGINX

You may now browse to and complete the WordPress installation. Please note that it does go pretty slow right now.

Runtime JS

There are two demos in the runtimejs directory:

  • hello-world: This is a very basic demo that will build a unikernel that outputs the text 'Hello StrangeLoop!' on the console out.
  • webserver: This is a simple webserver written in JS that responds to all requests on port 9000 with a 200 response code and the text 'Hello StrangeLoop!'

In order to build and run the demos run the following commands (from within the Vagrant box):

# Running from the shared directory is slow on VMware and
# terrible on VirtualBox so we'll clone it to the local fs.
git clone
cd lookma/runtimejs/scripts

# Run the hello-world demo:
cd ~/lookma/runtimejs/scripts
cd ../hello-world && npm start

# Run the webserver demo:
cd ~/lookma/runtimejs/scripts
cd ../webserver && npm start

LING (Erlang on Xen)

The LING demo is a basic webserver serving static content via an Erlang/OTP application. In this demo we compile the application and it's dependencies with rebar (the binary is included in this repo) and then package the tool using railing (also included here). The unikernel is then run on Xen and you are dropped into the Erlang shell on the system with the application started.

Getting this demo running is as simple as the rest:

# Running from the shared directory is slow on VMware and
# terrible on VirtualBox so we'll clone it to the local fs.
git clone
cd lookma/ling/scripts

# The machine has everything needed so no setup!
# Build the unikernel

# Run the unikernel

# See the results!

Links used to create these demos:




You can’t perform that action at this time.