Add taskworker that runs funcs out of process

src/taskworker.js

@@ -0,0 +1,44 @@
+'use strict';
+
+require('supererror')({ splatchError: true });
+
+var assert = require('assert'),
+    backups = require('./backups.js'),
+    database = require('./database.js'),
+    debug = require('debug')('box:taskworker'),
+    tasks = require('./tasks.js'),
+    updater = require('./updater.js');
+
+const NOOP_CALLBACK = function (error) { if (error) debug(error); };
+
+const TASKS = { // indexed by task type
+    backup: backups.backupBoxAndApps,
+    updater: updater.update,
+};
+
+process.on('SIGTERM', function () {
+    process.exit(0);
+});
+
+assert.strictEqual(process.argv.length, 3, 'Pass the taskid as argument');
+const taskId = process.argv[2];
+
+// Main process starts here
+debug(`Staring task ${taskId}`);
+
+database.initialize(function (error) {
+    if (error) return process.exit(50);
+
+    tasks.get(taskId, function (error, task) {
+        if (error) return process.exit(50);
+
+        const progressCallback = (progress) => tasks.update(taskId, progress, NOOP_CALLBACK);
+        const resultCallback = (error, result) => {
+            const progress = { percent: 100, result: result || '', errorMessage: error ? error.message : '' };
+
+            tasks.update(taskId, progress, () => process.exit(error ? 50 : 0));
+        };
+
+        TASKS[task.type].apply(null, task.args.concat(progressCallback).concat(resultCallback));
+    });
+});