Rework backuptask into tar.js

This makes it easy to integrate another backup strategy
as the next step

src/scripts/node.sh

@@ -1,23 +0,0 @@
-#!/bin/bash
-
-set -eu -o pipefail
-
-if [[ ${EUID} -ne 0 ]]; then
-    echo "This script should be run as root." > /dev/stderr
-    exit 1
-fi
-
-if [[ $# -eq 0 ]]; then
-    echo "No arguments supplied"
-    exit 1
-fi
-
-if [[ "$1" == "--check" ]]; then
-    echo "OK"
-    exit 0
-fi
-
-echo "Running node with memory constraints"
-
-# note BOX_ENV and NODE_ENV are derived from parent process
-exec env "DEBUG=box*,connect-lastmile" /usr/bin/node --max_old_space_size=300 "$@"

src/scripts/tar.js

@@ -0,0 +1,21 @@
+#!/usr/bin/env node
+
+'use strict';
+
+require('supererror')({ splatchError: true });
+
+var tar = require('tar-fs');
+
+var sourceDir = process.argv[2];
+
+process.stderr.write('Packing ' + sourceDir + '\n');
+
+tar.pack('/', {
+    dereference: false, // pack the symlink and not what it points to
+    entries: [ sourceDir ],
+    map: function(header) {
+        header.name = header.name.replace(new RegExp('^' + sourceDir + '(/?)'), '.$1'); // make paths relative
+        return header;
+    },
+    strict: false // do not error for unknown types (skip fifo, char/block devices)
+}).pipe(process.stdout);