andatche.com

Simple firewall for VPS

Ben — Thu, 02 Oct 2008 19:56:26 +0000

Because OpenVZ based VPS’ share a common kernel, some of the more advanced features of iptables such as connection state tracking etc aren’t available. This breaks many of the common firewall packages/scripts included in most distros such as shorewall and ufw that rely on such stuff to work.

The following is a basic init script to set up a simple iptables firewall, originally from here, with some modifications. By default all outgoing traffic is permitted, incoming responses are permitted on ports >1024 and connection requests are permitted for SSH, POP3(s), IMAP(s), SMTP(s) and HTTP(s). It’s a basic Red Hat style init script so you can sling it in /etc/init.d on Debian/Ubuntu.

Download: fw.txt

New PGP key

Ben — Mon, 30 Jun 2008 12:22:00 +0000

I’ve revoked my old PGP public key and replaced it with a 4096 bit DSA key, my new key is available here and is also listed on subkeys.pgp.net. Please update your keyring.

Vim cheat sheet

Ben — Tue, 03 Jun 2008 23:18:49 +0000

I use Vim on a daily basis but there are still occasions when I can’t quite remember the command I need. Laurent Grégoire has produced an excellent Vim Quick reference card available in a variety of languages and formats including PDF and HTML. It is released under the GNU GPL.

Downtime, a new home, VPS fun etc.

Ben — Tue, 27 May 2008 19:47:45 +0000

Recently I’ve been having a few problems with the web hosting provider I ~~use~~ used to use for this site and others. After a couple of years of solid service the last couple of months have proved to be anything but reliable. Performance was never anything to write home about but lately has become unacceptably poor. Couple that with intermittent down time over the last few weeks and the fact they managed to lose the contents of my home directory at the back end of last week and it was time to find a better solution!

After an unhelpful exchange with their support team it became apparent they couldn’t restore any of the lost content and had no backup procedure in place, luckily I have copies of anything that’s important. They seemed to have little interest in helping me and continued to reply with a generic message blaming a hardware fault, requesting that I re upload my files and offering a month’s free hosting for the inconvenience. Instead I chose to look elsewhere.

I’ve been toying with the idea of using a VPS for some time now and this offered the perfect excuse to move. After a little searching I settled on a solution with 256MB ram and the possibility of an easy upgrade in the future. A couple of days of setting-up/tweaking to get everything running nicely and here we are, andatche.com is back up at a new home! I’ve still got a few things to fine tune before I’ll be completely happy with everything but so far all is well.

Solaris sed annoyances

Ben — Thu, 10 Apr 2008 19:13:18 +0000

I have to spend a fair bit of time at work hacking away on Solaris boxes and have really started to miss some of the extra features of many GNU tools I really took for granted. One that really bugs me is the lack of in-place editing in Solaris sed (-i using GNU sed). Perl to the rescuse!
perl -pi -e 's/foo/bar/g' /path/to/file
The above is pretty functionally equivalent to sed -i. A quick alias in .bashrc:
alias sed-i='perl -pi -e'
and everything in life is well again.

Comment spam

Ben — Thu, 21 Feb 2008 20:20:19 +0000

I’ve been suffering lots of comment spam from spambots of late and decided to do something about it. Using Peter’s Custom Anti-Spam plugin for wordpress I’ve implemented a captcha on the comments form. The slight inconvenience this adds for users is more than worth the time saved removing spam comments.

Best spam ever…?

Ben — Wed, 13 Feb 2008 12:41:27 +0000

This is a spam email a collegue at work recieved, Dr. Seuss style. Made me chuckle.

That’s great you’ve found a gal that’s hot You wanna hump her juicy tw*t.
She’s so attractive, she’s so nice!
But would your penile size suffice?
Not sure she will long for more?
You need a wang she would adore!
But how to raise it long and thick?
Your only chance is MegaDik!
You’ll get so wanted super-size
And see great pleasure in her eyes!
Your shaft will slam her pink so deep,
Tonight you’ll hardly fall asleep!

So try today this wonder-pi’ll
And change your life at your own will!

Absent Friends

Ben — Tue, 23 Oct 2007 15:06:09 +0000

Paul Raven, bass player for Killing Joke, Ministry and others died unexpectedly of a heart attack in Geneva in the early hours of Saturday October 20th 2007. He will be sadly missed!!

It’s all text!

Ben — Wed, 08 Aug 2007 16:11:01 +0000

I found a pretty awesome extension for Mozilla Firefox today called It’s all text! It allows you to edit HTML textareas using an external editor (Such as Vim) from Firefox. This is really handy for writing long forum posts, blog posts, bug reports etc as I much prefer using Vim than any of the integrated text editors from stuff like VBulliten and Wordpress.

True Random Numbers

Ben — Thu, 19 Jul 2007 18:25:18 +0000

A true random number generator service has gone online courtesy of the Quantum Random Bit Generator Service developed at the Ruder Boškovic Institute in Croatia. The ‘Quantum Random Bit Generator’ at the heart of QRBGS is a fast non-deterministic random bit (number) generator whose randomness relies on intrinsic randomness of the quantum physical process of photonic emission in semiconductors and subsequent detection by photoelectric effect.

The service currently provides access via a stand alone CLI client as well as libraries for C/C++ and MATLAB plugins allowing users to request random bits in a number of data type such as int, long, float etc. This is excellent for application developers requiring high entropy randomness and is particularly useful for stuff such as cryptography and online gaming. It looks like access via a web service will be provided soon.