"not authorized" with auth turned on in Mongo

Question

I am following the directions here to try and install Mongo 3.6 w/ authentication turned on. I have added a "root" user and I am able to login using Mongo shell and I added a application user as well, but when I try to list DBs or collections using either root or the other userid I created I get the following error:

not authorized on on admin to execute command { listDatabase: 1.0, $db: \"admin\" }

I also get this when I try to login through my node app using the application user. What am I doing wrong?

Answer 1

Ok, so the problem was two-fold:

1. I had added the app user to the wrong database. It seems like all users should be added to admin, not the database you want to grant permissions on
2. I was missing some roles on my "root" user. The one that seemed to fix it was the "root" role
3. I was missing the role needed to list databases on my app user. I added clisterMonitor and that seemed to work.

Those 3 together seemed to allow me to show dbs, show collections, and call listDatabases from MongoClient.