making lxc containers inside vagrant accessible to the host machine

lxc vagrant iptables portforwarding | comments

In a previous post we got lxc running within a vagrant box. Richard Crowley asked if the container was accessible from outside the Vagrant box, i.e. from your mac or bare metal machine that runs Virtual Box. With some iptables we can make this happen. Assume the container has the ip Also within your Vagrantfile we forward a port, meaning that a port on the vagrant box is accessible on the underlying machine.

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zeromq from source

zeromq | comments

Instructions for installing zeromq from source alongside the Python bindings.

First install dependencies:

sudo apt-get install libtool autoconf automake g++ uuid-dev

Then get the source (this is for the current stable release 2.1.7) and untar it:

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lxc on the mac with vagrant

lxc vagrant linuxcontainers inception | comments

lxc, or linux containers, is the new hotness, with companies such as Heroku and DotCloud using it (I hear MongoHQ is looking into them as well), although it’s been around for a while now.

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pip workaround for no ppc support in xcode4

ppc xcode4 python | comments

Xcode4 has removed support for powerpc architectures, most notably for the gnu assembler which is needed for python packages that have ‘c’ extensions such as pycrypto (in turn needed for fabric). I have seen various solutions to this issue, the most elaborate one being reinstalling xcode3 alongside xcode4. If you are using pip for install your packages (you should) this is a more convenient solution:

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libcloud and ec2 keypairs

libcloud ec2 | comments

libcloud is my new favorite cloudy library. Some extra small tips to get you going with ec2:

ec2 requires a keypair to be coupled to an instance if you decide to get your ssh on with your newly created instance. Same goes for using security groups. Here’s how you create an instance with libcloud and pass a keypair called ‘ec2-keypair’ and a ‘default’ security group to it:

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python argparse | comments

I’ve been playing around with argparse the replacement python command-line argument parsing library but I couldn’t figure out how to do mutually exclusive arguments whereby one of the commands gets an extra argument and the other not, i.e.:

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Literature Study on Hybrid Dissemination Protocols

paper hybriddissemination protocols gossip deterministic literatureoveriew | comments

For my computer science Master at the VU (Vrije Universiteit) I had to conduct a literature study on a specific subject. With my coordinator, Guillaume Pierre I chose the subject of hybrid dissemination protocols. The paper was awarded with a 9 out of 10. This is the abstract:

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Moving to San Francisco

sanfrancisco moving thesis usf | comments

I’ll be moving to San Francisco in about a week to finish my Master’s thesis at the University of San Francisco. The thesis will be coordinated by a supervisor at USF as well by Guillaume Pierre at my own VU Amsterdam (Vrije Universiteit). I’ve been admitted to the Web Science graduate program with an emphasis in entrepreneurship at USF. I’ll be diving not only in technology but also some MBA courses such as product development and innovation processes. My Master’s thesis is concerned with the research and implementation of a large scale distributed routing system for cloud computing (suitable for PaaS offerings), built on top of distributed hash table technology and gossip protocols. Of course I’ll also be spending time with my friends in SF and I’m definitely looking forward to interacting with the startup community there!


node.js versus mochiweb

node.js mochiweb benchmark | comments

Jlouis recently ran some simple benchmarks on node.js versus Erlang in the context of Erlang’s preemptive multi-tasking versus node.js’ cooperative model if you look at both languages/frameworks from an Operating Systems perspective. I used the same code for a similar experimental setup, but ran these on my MacBook Air (not something you would do for a real web app, as goes for the actual code used, but that’s not the point). I benchmarked both the node.js and mochiweb applications, utilizing the code and the ‘heavy work loop’ as described by jlouis using Tsung. The load-progression model was simple, a 10 minute duration with a user arriving every second. I ran the response times of the request log through a custom python script to get the cumulative distribution function and plotted these with gnuplot:

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MacBook Air

macbookair macbook apple | comments

I got the new MacBook Air 13” with 4GB of RAM. My previous machine was a non-unibody alu 15” MacBook Pro. I’m not missing the bigger screen as the Air’s resolution is the same as of the 15” even though I’m stuck in terminals and vim windows a lot. It’s also very light-weight and battery life is excellent. The lack of a DVD drive is no bother to me as goes for the firewire input. I can imagine that at some point the absence of a wired network port could be a problem but I haven’t run into this yet. In short, I love the new Air and I can highly recommend it (and not just as a surfing/casual computing machine).