I started this post as a rehash of Modules with some additional details. However, as I started running my examples, I found out that while the documentation on modules is good, it does not tell the full story regarding exports. As I do not want to write a manifesto on module exports, I’m going to assume you already read the above document and understand Perl 6 exports. If not, go read it and I’ll wait for you to return.

I am working on a robotics project with my 3 boys. For this project, I have designed the core components to be a Raspberry Pi, an Adafruit Circuit Playground Express (CPX), and an Adafruit Crickit Hat. The Raspberry Pi will be running firmware written by me to control the Crickit Hat. This firmware will directly drive the sensors, the motors, the servo, and other hardware. The Raspberry Pi also communicates over USB to the CPX to provide high level sensor information and receive commands. My sons will be programming the CPX micro-controllers using Microsoft MakeCode which provides a simple block programming interface for the younger boys and a TypeScript interface to the oldest one.

For my first real post of my new blog, let’s talk about multi-stage docker builds. This blog is built with the aid of just such a build. A multi-stage docker build gives you the ability to build multiple containers. In the case of my build, it helps me build a single end-product that’s uncluttered by extra build configuration and tooling.

Why multi-stage?

Docker holds a place in the modern development pipeline for deployed applications similar to the role the classic Makefile has in building packaged applications. (There’s a reason the Dockerfile and Makefile use a similar nomenclature after all.) However, when building a deployed application, you often need to perform build tasks that create clutter. For example, if you’re building a C program, you’ll like need to install the build tools (sudo apt-get install build-essential) and then when you run make you get all those intermediate .o files needed for linking, and maybe you need to install Perl or Python to help run some of the glue code, etc.