operator: add app task status route

src/routes/apps.js

@@ -11,6 +11,7 @@ exports = module.exports = {
     exportApp,
     backup,
     update,
+    getTask,
     getLogs,
     getLogStream,
     listEventlog,
@@ -826,3 +827,13 @@ async function checkForUpdates(req, res, next) {
     await updateChecker.checkForUpdates({ automatic: false }); // appId argument is ignored for the moment
     next(new HttpSuccess(200, { update: updateChecker.getUpdateInfo() }));
 }
+
+async function getTask(req, res, next) {
+    assert.strictEqual(typeof req.app, 'object');
+
+    const [error, result] = await safe(apps.getTask(req.app));
+    if (error) return next(BoxError.toHttpError(error));
+    if (result === null) return next(new HttpError(400, 'No active task'));
+
+    next(new HttpSuccess(200, result));
+}