Have cache actually check cache

Cache has not been hitting the actual cache bits, so now we will tell it
to reach out to the cache server locally and check for the ISO to be
present in the bucket before we run the curl at all

nix/cache.nix

@@ -19,23 +19,18 @@ in writeShellApplication {
 		minio-client
 		packer
 	];
-	text = (concatStringsSep "\n" (
+	text = ''
+		mc alias set storage "$STORAGE_URL" root "$MINIO_SECRET"
+	'' + (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/)
-			if [ ! -e "cache/$sha.iso" ]; then
+			if [ -z "$(mc ls storage/isos/cache/ | grep $sha)" ]; then
 				curl --retry 3 --retry-all-errors -o "cache/$sha.iso" "$url"
+				mc put "cache/$sha.iso" "storage/isos/cache/$sha.iso"
 			else
 				echo "Skipping ${d.distro} - cache/$sha.iso"
 			fi
 		'') active
-	)) + ''
+	));
-		ls -lh cache/
-
-		mc alias set storage "$STORAGE_URL" root "$MINIO_SECRET"
-
-		for f in cache/*; do
-			mc put "$f" "storage/isos/$f"
-		done
-	'';
 }