nix with docker

[adminy]

Given that the only way to build docker images using a nix command needs to do docker load command, why was docker not built-in to nixos/nix? Or at least some image that has nixos/docker-nix

here is my example:

image:
	docker run --privileged \
		--mount type=bind,source=${PWD}/.github/workflows,target=/etc/nixos \
		--mount type=bind,source=/var/run/docker.sock,target=/var/run/docker.sock \
		-it nixos/nix nix-shell -p docker --run \
		"docker load --input \$$(nix-build /etc/nixos/image.nix)"
	# docker push