Create a MongoDB user from commandline

Question

I have set up a MongoDB database with an `admin` user that has only administrative rights, not read or write access to databases. What I now would want to do is: - Add a new database, - and add a new user to that database. And: I need to do this from the command line. So I tried: ``` $ mongo admin -u admin -p admin --eval "db.addUser('dummyuser', 'dummysecret')" ``` (Please note that as I am still running MongoDB 2.0, I am using the old format of `db.addUser`.) This would make perfect sense if I could also tell it which database this user should be for. But now I am struggling. How do I specify the database for this command? If I were in the interactive shell, I could just run ``` > use dummydb ``` but how do I do this from the command line? My first try was to concatenate both commands with a `;`, but this didn't work: ``` $ mongo admin -u admin -p admin --eval "use dummydb;db.addUser('dummyuser', 'dummysecret')" ``` just gives me syntax error. How do I get this right?

Accepted Answer

The `use db` syntax is only supported in an interactive shell session.

If you want to change databases from an admin script, you can use `db.getSiblingDB('dbname')`.

So your equivalent command line using `--eval` would be:

```
# MongoDB 2.6+: use createUser()
$ mongo admin -u admin -p admin --eval "db.getSiblingDB('dummydb').createUser({user: 'dummyuser', pwd: 'dummysecret', roles: ['readWrite']})"

# MongoDB 2.4: use addUser()
$ mongo admin -u admin -p admin --eval "db.getSiblingDB('dummydb').addUser('dummyuser', 'dummysecret')"
```

There is a section in the MongoDB manual covering Differences between interactive and scripted `mongo`. This includes equivalents for other interactive shell helpers such as `show dbs` and `show collections`.

Create a MongoDB user from commandline

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