MongoDB: Not authorized on admin to execute command - mongodb

Question

My mongo shell is giving me this error when I am using show dbs command.
not authorized on admin to execute command
I have tried to create a user using
db.createUser(
{
user: "siteUserAdmin",
pwd: "password",
roles: [ { role: "userAdminAnyDatabase", db: "admin" } ]
}
)
as on https://docs.mongodb.com/v2.6/tutorial/add-user-administrator/
But it still gives me the same error:
Could not add user: not authorized on admin to execute command.
I am using Ubuntu 16.04 and mongoDB version is 3.4.9

Answer 1

I think you can use the role as root for Ubuntu. Try the below query.
use admin
db.createUser(
{
user: "admin",
pwd: "password",
roles: [ { role: "root", db: "admin" } ]
}
);
exit;
You can give read write permission to user as well
use admin
db.grantRolesToUser("admin",["readWrite"])
EDIT
Since the above didn't work try to start the instance with auth as below
Stop the mongod instance
Start the instance with $ mongod --auth
Now start mongo shell and create user
use admin
db.createUser(
{
user: "admin",
pwd: "password",
roles: [ { role: "root", db: "admin" } ]
}
);
exit;
Now give permission
db.auth("admin", "password")
db.grantRolesToUser("password", [ { role: "readWrite", db: "admin" } ])
Now check show users