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/)
        	distro=$(echo var.distro | packer console -var-file="${distroFile d}" -config-type=hcl2 sources/)
        	# shellcheck disable=SC2143
        	if [ -z "$(mc ls "storage/isos/cache/$distro" | grep "$sha")" ]; then
        		curl -L --retry 3 --retry-all-errors -o "cache/$sha.iso" "$url"
        		if [ "$push" == "yes" ]; then
        			mc put "cache/$sha.iso" "storage/isos/cache/$distro/$sha.iso"
        		fi
        	else
        		echo "Skipping ${d.distro} - cache/$sha.iso"
        	fi
      '') active
    ));
}