As far as I can see, currently you only support %%BALENA_MACHINE_NAME%% and %%BALENA_ARCH%% replacements in Dockerfile.template (see here).
For the RaspberryPi 3 these are “raspberrypi3” and “armv7hf” respectively
Docker Hub seems to prefer the armXXvN notation (e.g. arm32v7); their reasoning can be found here:
Is there any plan to have an additional macro for this distinction?
My concrete example is haproxy:
I need “arm32v7/haproxy” and would prefer to write “%%BALENA_CPUARCH%%/haproxy” (or similar) in my Dockerfile.template. After all, that’s the idea of docker file templates.