22 May 2013
by Deimos
0 comments
Once again, I would like to introduce a limitation software. This time, this is for network bandwidth. With trickle, you can limit upload and download of an application.
Good written application embed this kind of features, but if it’s not the case it’s easy to do so with Trickle. See my documentation on Trickle to get more informations.
20 May 2013
by Deimos
0 comments
When you manage outgoing emails through SMTP, you may sometimes need to test if a service is able to send correctly emails and itself check that there were no issue during sending. You can create a black hole for a specific domain and Postfix will answer from the same manner as if it is ok. It also permit to test Postfix sending capacities on a server.
To get more informations on this, follow that link.
18 May 2013
by Deimos
0 comments
In a sad scenario where an application is fully consuming CPU to limit it. To do so, you will need a magic command called Cpulimit that will help you to limit a PID to a desired percentage usage of your CPU.
I’ve wrote a little documentation on cpulimit.
16 May 2013
by Deimos
0 comments
I recently flushed my Google Reader stars that I had and didn’t write down since 2009. There was a huge amount of work, but I did it. Now my account could be close without any missing things.
I wrote down some of tips and I share them with you :
I hope it will helps you 
14 May 2013
by Deimos
0 comments
Nginx Substitutions Filter is a filter module able to do both regular expression and fixed string substitutions on response bodies. This module is quite different from the Nginx’s native Substitution Module. It scans the output chains buffer and matches string line by line, just like Apache’s mod_substitute.
I’ve played with the classic substitution module but due to limitations (only one matching pattern and no regex), it wasn’t easy to do all I wanted to do. That’s why I’ve searched a better module to add on my Nginx servers. Unfortunately, this module is not currently available in Nginx packages, on Debian. So I’ve created new packages with Substitutions Filter module built in.
To get a quick overview of what this module is able to do, we’re going to take an example. Let’s say we need to add a CSS style on every pages on our websites. You’ve got multiple solutions to do it and most of them need to modify the application code. The problem is, each time you will have an application upgrade, you’ll need to think about this modifications. The other solution (if possible) is to create an extension for you application, but it’s boring to manage and time consuming.
With that solution, you can change the end of the HTML head banner and add any style or JS banner you want. It works with everything in the HTML code in fact. As described, it’s a string replacement solution. This extension is really powerful.
You can find my documentation on how to compile and package it for Debian.
Update : this has been added in experimental repository of Debian : 706456
12 May 2013
by Deimos
0 comments
It´s been a while that I was waiting for a tool that tells me if my Debian server is requesting a reboot or not. Of course GUI tools exists (like Ubuntu update-manager), but on a server machine, where there is no X server installed (thankfuly), this kind of CLI tools can be quickly interesting.
That´s why I wrote a tool called deb_reboot that gives the reboot requierement information in parsing postinstall scripts of installed packages.
You can find deb_tool on :
10 May 2013
by Deimos
0 comments
How could this happen ? I found a communication on that and it has simply been removed as there were no updates since a long time. Even if CVE were recently proposed, it’s considered as not enough :
http://debian.2.n7.nabble.com/Status-of-haproxy-for-upcoming-wheezy-release-td2907665.html
But guys ! Seriously, do you know how many people are using HAproxy ? It’s a shame that it’s not in the current stable version of Debian. Now let’s check the availability on all Debian versions, it’s currently only on oldstable and experimental versions :
http://packages.debian.org/search?keywords=haproxy&searchon=names&suite=all§ion=all
So what next ? Should we use another solution as it’s not available in Wheezy or should be do package pinning ? For the first time, I’m really not happy with a Debian decision. The final answer is finally there, “wait the backport availability” :
http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=674447#53
I hope this will be done shortly