What does Pee Wee Herman have to do with YAML?

Indeed, I often feel that XML documents, when compared with equivalent YAML files, demonstrate all the grace and calm reserve of a Pee-wee Herman chase scene (complete with rope swing, speedboat, sleigh, and man in a Godzilla costume).

That’s a quote from this book by André Ben Hamou, and it’s pretty much exactly how I feel about data serialisation. YAML has become my go-to format for just about everything. Why I love YAML:

• It’s really easy to map out and visualise complex data structures, especially in languages like Perl where this can be a bit of a pain.
• It’s completely cross-platform. so I can transport stuff between all the languages I write (yeah, OK, both of them if you don’t count 37 dialects of shell).
• It’s safe — no eval required
• Once your code is built to marshal/unmarshal using YAML, adding support for more formats (JSON, XML, language-native formats) is a piece of piss.

I will never write a config file parser again, nor hinky semi-structured report formats.

Thinking About Test-Driven Systems Administration

So I’ve been thinking about, and working on, this for a little while.

It was prompted mainly by the title of a paper Geoff Halprin gave at last year’s SAGE-AU conference. Not having had the time to attend the conference itself last year, I have no idea whether my approach bears any resemblance at all to Geoff’s.

Broadly speaking, systems administration consists of two main tasks: managing planned change to systems, and managing unplanned incidents on systems. Everything else we do is just arranging affairs so that change is simpler and more deterministic, and incidents are shorter and less frequent.

How, then, can a test-driven approach help with this? It seems to me that we need two things:

• A test-first workflow that makes sense for systems management
• A language and toolkit for expressing tests and collecting the output.

This seems like a pretty simple task. I’ll explore it a bit in the next few weeks.

Neat systems management hack using clamav

From the clamav-users list, last year (yes, I’m behind on my reading):

Clamav was used in Debian to discover copies of statically linked
copies of zlib that needed a security update.

http://www.enyo.de/fw/security/zlib-fingerprint/