Manage Database Users Using X.509 Authentication

The Kubernetes Operator supports managing database users for deployments running with TLS and X.509 internal cluster authentication enabled.

Supported Authentication Mechanisms

The Kubernetes Operator supports SCRAM, LDAP, and X.509 authentication mechanisms in deployments it creates. In an Kubernetes Operator-created deployment, you cannot use Ops Manager to:

  • Configure other authentication mechanisms for deployments.
  • Manage users not using SCRAM, LDAP, or X.509 authentication.

After enabling X.509 authentication, you can add X.509 users using the Ops Manager interface or the CustomResourceDefinition.


Before managing database users, you must deploy a replica set or sharded cluster with TLS and X.509 enabled.

If you need to generate X.509 certificates for your MongoDB users, see Generate X.509 Client Certificates.

Add a Database User


Configure kubectl to default to your namespace.

If you have not already, run the following command to execute all kubectl commands in the namespace you created.


If you are deploying an Ops Manager resource in a multi-Kubernetes-cluster deployment:

  • Set the context to the name of the central cluster, such as: kubectl config set context "$MDB_CENTRAL_CLUSTER_FULL_NAME".
  • Set the --namespace to the same scope that you used for your multi-Kubernetes-cluster deployment, such as: kubectl config --namespace "mongodb".
kubectl config set-context $(kubectl config current-context) --namespace=<metadata.namespace>

Copy the following example CustomResourceDefinition.

kind: MongoDBUser
  name: <resource-name>
  username: <rfc2253-subject>
  db: "$external"
    name: '<MongoDB-Resource-name>'
    - db: <database-name>
      name: <role-name>

Open your preferred text editor and paste the example CustomResourceDefinition into a new text file.


Change the lines for the following parameters, as needed.

Use the following table to guide you through changing the relevant lines in the MongoDB User Resource Specification:

Key Type Description Example string

The name of the database user resource.

Resource names must be 44 characters or less.

spec.username string

The subject line of the x509 client certificate signed by the Kubernetes CA (Kube CA).


The username must comply with the RFC 2253 LDAPv3 Distinguished Name standard.

To get the subject line of the X.509 certificate, run the following command:

openssl x509 -noout \
  -subject -in <my-cert.pem> \
  -nameopt RFC2253
CN=mms-user,U=My Organizational Unit,O=My Org,L=New York,ST=New York,C=US string The name of the project containing the MongoDB database where user will be added. The setting is an alias for this setting and can be used in its place. my-project
spec.roles.db string The database the role can act on. admin string The name of the MongoDB resource to which this user is associated. my-resource string The name of the role to grant the database user. The role name can be any built-in MongoDB role or custom role that exists in Cloud Manager or Ops Manager. readWriteAnyDatabase

Add any additional roles for the user to the CustomResourceDefinition.

You may grant additional roles to this user using the format defined in the following example:

kind: MongoDBUser
  name: mms-user-1
  username: CN=mms-user,U=My Organizational Unit,O=My Org,L=New York,ST=New York,C=US
  project: my-project
  db: "$external"
    - db: admin
      name: backup
    - db: admin
      name: restore

Create the user.

Invoke the following Kubernetes command to create your database user:

kubectl apply -f <database-user-conf>.yaml

When you create a new MongoDB database user, Kubernetes Operator automatically creates a new Kubernetes secret. The Kubernetes secret contains the following information about the new database user:

  • username: Username for the database user
  • password: Password for the database user
  • connectionString.standard: Standard connection string that can connect you to the database as this database user.
  • connectionString.standardSrv: DNS seed list connection string that can connect you to the database as this database user.


Alternatively, you can specify an optional spec.connectionStringSecretName field in the MongoDB User Resource Specification to specify the name of the connection string secret that the Kubernetes Operator creates.

You can use these credentials to Connect to a MongoDB Database Resource from Inside Kubernetes.


View the newly created user in Cloud Manager or Ops Manager.

You can view the newly-created user in Cloud Manager or Ops Manager:

  1. From the Project’s Deployment view, click the Security tab.
  2. Click the MongoDB Users nested tab.

Delete a Database User

To delete a database user, pass the from the user ConfigMap to the following command:

kubectl delete mdbu <>