backups: add setPrimary route

src/routes/backuptargets.js

@@ -13,6 +13,7 @@ exports = module.exports = {
     setLimits,
     setSchedule,
     setRetention,
+    setPrimary,
 
     create,
     cleanup,
@@ -214,3 +215,12 @@ async function setRetention(req, res, next) {
 
     next(new HttpSuccess(200, {}));
 }
+
+async function setPrimary(req, res, next) {
+    assert.strictEqual(typeof req.body, 'object');
+
+    const [error] = await safe(backupTargets.setPrimary(req.resources.backupTarget));
+    if (error) return next(BoxError.toHttpError(error));
+
+    next(new HttpSuccess(200, {}));
+}