vms/nix/cache.nix

{
	writeShellApplication,
	active,
	distroFile,

	curl,
	minio-client,
	packer,

	...
}:

let
	inherit (builtins) concatStringsSep map;
in writeShellApplication {
	name = "cache-isos";
	runtimeInputs = [
		curl
		minio-client
		packer
	];
	text = ''
		push="''${1:-yes}"
		if [ "$push" == "yes" ]; then
			mc alias set storage "$STORAGE_URL" root "$MINIO_SECRET"
		fi
		mkdir -p cache
	'' + (concatStringsSep "\n" (
		map (d: ''
			url=$(echo var.iso.url | packer console -var-file="${distroFile d}" -config-type=hcl2 sources/)
			sha=$(echo var.iso.checksum | packer console -var-file="${distroFile d}" -config-type=hcl2 sources/)
			# shellcheck disable=SC2143
			if [ -z "$(mc ls storage/isos/cache/ | grep "$sha")" ]; then
				curl -L --retry 3 --retry-all-errors -o "cache/$sha.iso" "$url"
				if [ "$push" == "yes" ]; then
					mc put "cache/$sha.iso" "storage/isos/cache/$sha.iso"
				fi
			else
				echo "Skipping ${d.distro} - cache/$sha.iso"
			fi
		'') active
	));
}