Tuesday, November 21, 2006

Good Unix-related blog

Vladimir Melnikoff brought his blog to my attention: "Nothing but Unix". Good resource for Unix enthusiasts, mostly composed of industry-related news.

Python Fuzz Testing Tools

Ian Bicking suggested I create a new category in the Python Testing Tools Taxonomy: Fuzz Testing or Fuzzing. Done. If you're not familiar with the term, see the Wikipedia article which talks about this type of testing. Here's an excerpt: "The basic idea is to attach the inputs of a program to a source of random data ("fuzz"). If the program fails (for example, by crashing, or by failing built-in code assertions), then there are defects to correct. The great advantage of fuzz testing is that the test design is extremely simple, and free of preconceptions about system behavior."

Ian told me about the Peach Fuzzer Framework. I was familiar with Pester (the home page talks about a Java tool called Jester, and it has links to the Python version called Pester); I also googled some more and found other Python fuzzing tools such as antiparser and Taof, which are both geared towards fuzzing network protocols. In fact, many fuzzing tools are used in security testing because they can aid in attacking software via random inputs. See this Hacksafe article on "Fuzz testing tools and techniques" and this PacketStorm list of fuzzing tools. Another good overview is Elliotte Harold's developerWorks article on fuzz testing. Very interesting stuff. If the "Python Testing Tools" tutorial Titus and I proposed for PyCon gets accepted, expect to see some fuzz testing included in our arsenal :-)

I also added Ian's minimock tool to the PTTT page. Very cool minimal approach to mock testing, achieved by embedding mocking constructs in doctests.

In other testing-related blog posts, Titus talks about the difficulty of retrofitting testing to an existing application (even when you wrote the testing tools!), and Max Ischenko presents some uber-cool plugins which integrate nose into vim.

Thursday, November 02, 2006

"Swap space management" article at IBM developerWorks

From IBM developerWorks, a very nice summary of the issues involved in setting up and maintaining swap space on *nix systems: "Swap space management and tricks".

Wednesday, November 01, 2006

Daniel Read on software and Apgar scores

Daniel Read blogs on the topic: "Does software need an Apgar score?". He mentions the fact that a simple metric (the Apgar score for newborns) revolutionized the childbirth process, "through standardization of techniques, training, and regulation of who exactly was allowed to perform certain procedures (based on whether they had the training and experience)". He then talks about how a similar simple score might help the quality of software development, by assessing its "health". Hmmm... all this sounds strangely familiar to me -- Cheesecake anybody? Of course, Daniel accepts that this idea is highly controversial and maybe a bit simplistic. However, I for one am convinced that it would help with improving, if not the quality, then at least the kwalitee of the software packages we see in the wild today.

Modifying EC2 security groups via AWS Lambda functions

One task that comes up again and again is adding, removing or updating source CIDR blocks in various security groups in an EC2 infrastructur...