97 Things Every Programmer Should Know

Chapter 61. One Binary

Steve Freeman

I’VE SEEN SEVERAL PROJECTS where the build rewrites some part of the code to generate a custom binary for each target environment. This always makes things more complicated than they should be, and introduces a risk that the team may not have consistent versions on each installation. At a minimum, it involves building multiple, near-identical copies of the software, each of which then has to be deployed to the right place. It means more moving parts than necessary, which means more opportunities to make a mistake.

I once worked on a team where every property change had to be checked in for a full build cycle, so the testers were left waiting whenever they needed a minor adjustment (did I mention that the build took too long as well?). I also worked on a team where the system administrators insisted on rebuilding from scratch for production (using the same scripts that we did), which meant that we had no proof that the version in production was the one that had been through testing. And so on.

The rule is simple: Build a single binary that you can identify and promote through all the stages in the release pipeline. Hold environment-specific details in the environment. This could mean, for example, keeping them in the component container, in a known file, or in the path.

If your team either has a code-mangling build or stores all the target settings ...