A few weeks ago I was in the “post-holiday doldrums” and needed a lift out of my rut. I was missing Lisp (hadn’t written any Lisp code in two years); was curious about the details of the EC2 API protocol; and wanted a better environment for managing our Sierra instances that fit my style of working (I’m an old system-software guy that uses Emacs and Bash a lot).  So I took a couple of days and wrote an EC2 API for Common Lisp, and then built a Sierra management interface on top of that. As it turned out, there were several open-source Common Lisp packages that helped: Edi Weitz’s drakma, a tidy web client; ironclad, an easy-to-use cryptography package; s-xml, a simple xml parser; and s-base64 for simple base64 encoding/decoding. Using these packages I had a functioning EC2 interface in half a day, and by the third day the package had everything I needed to build my Sierra layer on top. The decisive advantage this approach has over my previous python command-line interface is that my Sierra environment is running all the time (Lisp within an Emacs session); and thus I am able to interact with Sierra via the Lisp REPL., make changes without having to restart my Sierra environment, etc. Very cool.

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