Setting-up PAM and LDAP

by Sebastien Mirolo on Tue, 15 May 2012

The Plan

I wanted to setup my web app to authenticate through PAM as a general authentication mechanism. Since users are allowed to register and update password through the web app directly, I indented to use LDAP to hold user profile information. So I delve into setting-up PAM and LDAP. read more...

Packaging Python Apps

by Sebastien Mirolo on Sun, 22 Apr 2012

I have never quite understood why python (or ruby) packages are delivered through their own manager (pip, gem) instead of the local system package manager (apt, yum, etc). I mean I understand the python developer rationale and disagrees with it. My main problem with side-stepping the local package manager is that now the programming stack of prerequisites matters, a lot. It is not just about dependencies and APIs anymore but also about which package manager to use. That creates tons of problems especially when you rely on something with some very problematic design issues like easy_install. read more...

Starting with Condor

by Sebastien Mirolo on Fri, 2 Mar 2012

Condor is a job scheduler used to do batch processing on a cluster of machines. dagman is built on top of condor to manage jobs dependencies. The manual is pretty good and after you read through it a few times you will surely want to bookmark the condor_submit reference page to quickly find the Submit Description File Commands. I will just go through the issues I stumbled upon as a newbie. read more...

Backups with rsnapshot

by Sebastien Mirolo on Sat, 22 Oct 2011

First I created a cron job to dump the databases running on production servers in SQL format. read more...

Authentication using OpenLDAP

by Sebastien Mirolo on Sat, 8 Oct 2011

In the most part I followed the ubuntu 11.04 openldap tutorial. The wikipedia article is also useful to understand some of the basics. I later stumbled upon LDAP for Rocket Scientists which definitely helped clarify some. read more...

Denying comment spam bots

by Sebastien Mirolo on Sat, 23 Apr 2011

It is kind of fun to look through your application logs and find traces of a hacker trying to break in. It might even be intellectually stimulating to play this game of hide and seek with another human being. Unfortunately most malicious attempts hitting your server will come from bots. Those don't get discouraged. Those don't change tactics. They keep trying to brute force passwords, even when you only allow private key login in your ssh daemon. They keep trying to access PHP scripts, even when you do not have any PHP stack running on your web server. Worse, if you allow people to leave comments on your web site, you are almost guarantee to attract spam bots that will waste precious bandwidth and mess up statistics you use to learn about your audience. read more...

Virtual Machines Server

by Sebastien Mirolo on Sat, 8 Jan 2011

Ubuntu 10.10 comes with support for Virtual Machines. As I started to port fortylines testing infrastructure to a new more quiet machine, it is a good time to start playing around with virtual machine provisioning and decommissioning. read more...

Booting Ubuntu from USB stick

by Sebastien Mirolo on Tue, 16 Nov 2010

Ubuntu 10.10 comes with support for Virtual Machines. As I started to port fortylines testing infrastructure to a new more quiet machine, it is a good time to start playing around with virtual machine provisionning and decomisionning. read more...

Running fop on an headless server

by Sebastien Mirolo on Sun, 31 Oct 2010

fop is a useful tool in the process of formatting documentation as pdf when you start with docbook marked-up documents. Unfortunately on some machine you end-up with the following result when running the tool. read more...

Lost SSH Connection and GNU screen

by Sebastien Mirolo on Thu, 9 Sep 2010

I had to do work remotely on a machine that required long session recently and the ssh connection kept dropping at random. It is very annoying and it seems almost impossible to track it down. The best explanation so far looks to lie with the way routers, firewalls and other bridges between me and the remote machine maintain some sanity into their NAT tables. In any case, I started to use GNU screen such that least running jobs do not just get killed off when the connection dropped. read more...

Ubuntu Server and VMware Fusion

by Sebastien Mirolo on Sat, 17 Oct 2009

Anticipated the upcoming next release of Ubuntu, I decided to setup an Ubuntu Server Edition sandbox under VMware to test the configuration scripts. I do not know about you, but I feel a little anxious about upgrading the customer-facing Internet server, fixing bugs in real-time. read more...