Cannot authenticate into mongo, “auth fails”

Question

I\'ve created an admin user for mongo using these directions:

http://docs.mongodb.org/manual/tutorial/add-user-administrator/

From the mongo client it looks

Answer 1

I also received this error, what I needed was to specify the database where the user authentication data was stored:

mongo -u admin -p SECRETPASSWORD --authenticationDatabase admin

Update Nov 18 2017:

mongo admin -u admin -p

is a better solution. Mongo will prompt you for your password, this way you won't put your cleartext password into the shell history which is just terrible security practice.