Heptapod CI: building bootstrapped images with Kaniko
A later problem is that we will need to also produce the 'testing' image (or maybe have omnibus produce it for tag builds only, or just get rid of it entirely). Attempts at building the two images in a single call so far have failed. Notably, --cache will want to push its cached layers to a local registry, defaulting to registry.h.n to which upload is very slow. Also, it is not clear what the end step would be after running Kaniko twice in the same filesystem (not what Kaniko is designed for). Perhaps we can hope for a new Kaniko feature to become available later on, like pushing two build stages defined in a single Dockerfile? In the mean time let's just accept the possibility of an unnecessary pull of the bootstrapped image (not so grim).