Docs Menu

Use SCRAM to Authenticate Clients

On this page

  • Procedure
  • Next Steps

The following procedure sets up SCRAM for client authentication on a standalone mongod instance.

To use SCRAM authentication for replica sets or sharded clusters, see Deploy Replica Set With Keyfile Authentication.

1

Start a standalone mongod instance without access control.

Open a terminal and run the following command:

mongod --port 27017 --dbpath /var/lib/mongodb

The mongod instance in this tutorial uses port 27017 and the /var/lib/mongodb data directory. The tutorial assumes that the /var/lib/mongodb directory exists and is the default dbPath. You may specify a different data directory or port as needed.

2

Open a new terminal and connect to the database deployment with mongosh:

mongosh --port 27017

If you are connecting to a different deployment, specify additional command line options, such as --host, as needed to connect.

3
Important
Localhost Exception

You can create the user administrator either before or after enabling access control. If you enable access control before creating any user, MongoDB provides a localhost exception which allows you to create a user administrator in the admin database. Once created, you must authenticate as the user administrator to create additional users.

Using mongosh:

  1. switch to the admin database
  2. add the myUserAdmin user with the userAdminAnyDatabase and readWriteAnyDatabase roles":
use admin
db.createUser(
{
user: "myUserAdmin",
pwd: passwordPrompt(), // or cleartext password
roles: [
{ role: "userAdminAnyDatabase", db: "admin" },
{ role: "readWriteAnyDatabase", db: "admin" }
]
}
)
Tip

The passwordPrompt() method prompts you to enter the password. You can also specify your password directly as a string. We recommend to use the passwordPrompt() method to avoid the password being visible on your screen and potentially leaking the password to your shell history.

The userAdminAnyDatabase role allows this user to:

  • create users
  • grant or revoke roles from users
  • create or modify customs roles

You can assign your user additional built-in roles or user-defined roles as needed.

The database where you create the user, in this example admin, is the user's authentication database. Although the user needs to authenticate to this database, the user can have roles in other databases. The user's authentication database doesn't limit the user's privileges.

4

Shut down the mongod instance. Using mongosh, issue the following command:

db.adminCommand( { shutdown: 1 } )

Exit mongosh.

Start the mongod with access control enabled.

Clients that connect to this instance must now authenticate themselves and can only perform actions as determined by their assigned roles.

Important
Localhost Exception

You can create users either before or after enabling access control. If you enable access control before creating any user, MongoDB provides a localhost exception which allows you to create a user administrator in the admin database. Once created, you must authenticate as the user administrator to create additional users.

5

Using mongosh, you can:

To use SCRAM authentication for replica sets or sharded clusters, see Deploy Replica Set With Keyfile Authentication.

←  SCRAMx.509 →
Give Feedback
© 2021 MongoDB, Inc.

About

  • Careers
  • Legal Notices
  • Privacy Notices
  • Security Information
  • Trust Center
© 2021 MongoDB, Inc.