Users

MongoDB user accounts within the Cluster can be divided into two different groups:

• application-level users: the unprivileged user accounts,
• system-level users: the accounts needed to automate the cluster deployment and management tasks, such as MongoDB Health checks.

As these two groups of user accounts serve different purposes, they are considered separately in the following sections.

Unprivileged users

The Operator does not create unprivileged (general purpose) user accounts by default. There are two ways to create general purpose users:

• manual creation of custom MongoDB users,
• automated users creation via Custom Resource (Operator versions 1.17.0 and newer).

Create users in the Custom Resource

Starting from the Operator version 1.17.0 declarative creation of custom MongoDB users is supported via the users subsection in the Custom Resource.

Warning

Declarative user management has technical preview status and is not yet recommended for production environments.

You can change users section in the deploy/cr.yaml configuration file at the cluster creation time, and adjust it over time.

You can specify a new user in deploy/cr.yaml configuration file, setting the user’s login name and database, a reference to a key in some Secret resource that contains user’s password, as well as MongoDB roles on various databases which should be assigned to this user. You can find detailed description of the corresponding options in the Custom Resource reference, and here is a self-explanatory example:

...
users:
  - name: my-user
    db: admin
    passwordSecretRef: 
      name: my-user-password
      key: password
    roles:
      - name: clusterAdmin
        db: admin
      - name: userAdminAnyDatabase
        db: admin

The Secret mentioned in the users.passwordSecretRef.name option should look as follows:

apiVersion: v1
kind: Secret
metadata:
  name: my-user-password
type: Opaque
stringData:
  password: mypassword

The Operator tracks password changes in the Sectet object, and updates the user password in the database. This applies to the manually created users as well: if a user was created manually in the database before creating user via Custom Resource, the existing user is updated. But manual password updates in the database are not tracked: the Operator doesn’t overwrite changed passwords with the old ones from the users Secret.

Custom MongoDB roles

Custom MongoDB roles allow providing fine-grained access control over your MongoDB deployment.

Custom MongoDB roles can be defined in a declarative way via the roles subsection in the Custom Resource.

Warning

Custom roles were introduced in the Operator version 1.18.0. It has technical preview status and is not yet recommended for production environments.

This subsection contains array of roles each with the defined custom name (roles.name), database in which you want to store the user-defined role (roles.db). The roles.privileges.actions allows to set List of custom role actions that users granted this role can perform. For a list of accepted values, see Privilege Actions  in the manual of the corresponding MongoDB version. Actions can be granted for the whole cluster (if roles.privileges.resource.cluster set to true), or be related to a specific database or collection. Adding existing role and database names to the roles.roles subsection allows you to inherit privileges from existing roles. Finally, you can apply authentication restrictions for your custom role based on the IP address ranges for the client and server. The following example shows how roles subsection may look like:

roles:
    - role: my-role
      db: admin
      privileges:
        - resource:
            db: ''
            collection: ''
          actions:
            - find
      authenticationRestrictions:
        - clientSource:
            - 127.0.0.1
          serverAddress:
            - 127.0.0.1
      roles:
        - role: read
          db: admin
        - role: readWrite
          db: admin

Find more infromation about available options and their accepted values in the roles subsection of the Custom Resource reference.

Create users manually

You can create unprivileged users manually. Please run commands below, substituting the <namespace name> placeholder with the real namespace of your database cluster:

if sharding is onif sharding is off

$ kubectl run -i --rm --tty percona-client --image=percona/percona-server-mongodb:7.0.14-8 --restart=Never -- bash -il
mongodb@percona-client:/$
$ mongosh "mongodb://userAdmin:userAdmin123456@my-cluster-name--mongos.<namespace name>.svc.cluster.local/admin?ssl=false"
rs0:PRIMARY> db.createUser({
    user: "myApp",
    pwd: "myAppPassword",
    roles: [
      { db: "myApp", role: "readWrite" }
    ],
    mechanisms: [
       "SCRAM-SHA-1"
    ]
})

Now check the newly created user:

$ kubectl run -i --rm --tty percona-client --image=percona/percona-server-mongodb:7.0.14-8 --restart=Never -- bash -il
mongodb@percona-client:/$ mongosh "mongodb+srv://myApp:myAppPassword@my-cluster-name-rs0.<namespace name>.svc.cluster.local/admin?replicaSet=rs0&ssl=false"
rs0:PRIMARY> use myApp
rs0:PRIMARY> db.test.insert({ x: 1 })
rs0:PRIMARY> db.test.findOne()

$ kubectl run -i --rm --tty percona-client --image=percona/percona-server-mongodb:7.0.14-8 --restart=Never -- bash -il
mongodb@percona-client:/$
$ mongosh "mongodb+srv://userAdmin:userAdmin123456@my-cluster-name-rs0.<namespace name>.svc.cluster.local/admin?replicaSet=rs0&ssl=false"
rs0:PRIMARY> db.createUser({
    user: "myApp",
    pwd: "myAppPassword",
    roles: [
      { db: "myApp", role: "readWrite" }
    ],
    mechanisms: [
       "SCRAM-SHA-1"
    ]
})

Now check the newly created user:

$ kubectl run -i --rm --tty percona-client --image=percona/percona-server-mongodb:7.0.14-8 --restart=Never -- bash -il
mongodb@percona-client:/$ mongosh "mongodb+srv://myApp:myAppPassword@my-cluster-name-rs0.<namespace name>.svc.cluster.local/admin?replicaSet=rs0&ssl=false"
rs0:PRIMARY> use myApp
rs0:PRIMARY> db.test.insert({ x: 1 })
rs0:PRIMARY> db.test.findOne()

System Users

To automate the deployment and management of the cluster components, the Operator requires system-level MongoDB users.

Credentials for these users are stored as a Kubernetes Secrets object. The Operator requires Kubernetes Secret before the database cluster is started. It will either use existing Secret or create a new Secret with randomly generated passwords if it didn’t exist. The name of the required Secret should be set in the spec.secrets.users option of the deploy/cr.yaml configuration file.

Default Secret name: my-cluster-name-secrets

Secret name field: spec.secrets.users

Warning

These users should not be used to run an application.

User Purpose	Username Secret Key	Password Secret Key
Backup/Restore	MONGODB_BACKUP_USER	MONGODB_BACKUP_PASSWORD
Cluster Admin	MONGODB_CLUSTER_ADMIN_USER	MONGODB_CLUSTER_ADMIN_PASSWORD
Cluster Monitor	MONGODB_CLUSTER_MONITOR_USER	MONGODB_CLUSTER_MONITOR_PASSWORD
Database Admin	MONGODB_DATABASE_ADMIN_USER	MONGODB_DATABASE_ADMIN_PASSWORD
User Admin	MONGODB_USER_ADMIN_USER	MONGODB_USER_ADMIN_PASSWORD
PMM Server	PMM_SERVER_USER	PMM_SERVER_PASSWORD

Password-based authorization method for PMM is deprecated since the Operator 1.13.0. Use token-based authorization instead.

• Backup/Restore - MongoDB Role: backup , restore , clusterMonitor , readWrite , pbmAnyAction

• Cluster Admin - MongoDB Roles: clusterAdmin

• Cluster Monitor - MongoDB Role: clusterMonitor , read (on the local database), explainRole

• Database Admin - MongoDB Roles: readWriteAnyDatabase , readAnyDatabase , dbAdminAnyDatabase , backup , restore , clusterMonitor

• User Admin - MongoDB Role: userAdminAnyDatabase

If you change credentials for the MONGODB_CLUSTER_MONITOR user, the cluster Pods will go into restart cycle, and the cluster can be not accessible through the mongos service until this cycle finishes.

Note

In some situations it can be needed to reproduce system users in a bare-bone MongoDB. For example, that’s a required step in the migration scenarios to move existing on-prem MongoDB database to Kubernetes-based MongoDB cluster managed by the Operator. You can use the following example script which produces a text file with mongo shell commands to create needed system users with appropriate roles:

gen_users.sh

clusterAdminPass="clusterAdmin"
userAdminPass="userAdmin"
clusterMonitorPass="clusterMonitor"
backupPass="backup"

# mongo shell
cat <<EOF > user-mongo-shell.txt
use admin
db.createRole(
{
"roles": [],
role: "pbmAnyAction",
"privileges" : [
                {
                        "resource" : {
                                "anyResource" : true
                        },
                        "actions" : [
                                "anyAction"
                        ]
                }
        ],

})

db.createUser( { user: "clusterMonitor", pwd: "$clusterMonitorPass", roles: [ "clusterMonitor" ] } )
db.createUser( { user: "userAdmin", pwd: "$userAdminPass", roles: [ "userAdminAnyDatabase" ] } )
db.createUser( { user: "clusterAdmin", pwd: "$clusterAdminPass", roles: [ "clusterAdmin" ] } )
db.createUser( { user: "backup", pwd: "$backupPass", roles: [ "readWrite", "backup", "clusterMonitor", "restore", "pbmAnyAction" ] } )
EOF

YAML Object Format

The default name of the Secrets object for these users is my-cluster-name-secrets and can be set in the CR for your cluster in spec.secrets.users to something different. When you create the object yourself, the corresponding YAML file should match the following simple format:

apiVersion: v1
kind: Secret
metadata:
  name: my-cluster-name-secrets
type: Opaque
stringData:
  MONGODB_BACKUP_USER: backup
  MONGODB_BACKUP_PASSWORD: backup123456
  MONGODB_DATABASE_ADMIN_USER: databaseAdmin
  MONGODB_DATABASE_ADMIN_PASSWORD: databaseAdmin123456
  MONGODB_CLUSTER_ADMIN_USER: clusterAdmin
  MONGODB_CLUSTER_ADMIN_PASSWORD: clusterAdmin123456
  MONGODB_CLUSTER_MONITOR_USER: clusterMonitor
  MONGODB_CLUSTER_MONITOR_PASSWORD: clusterMonitor123456
  MONGODB_USER_ADMIN_USER: userAdmin
  MONGODB_USER_ADMIN_PASSWORD: userAdmin123456
  PMM_SERVER_USER: admin
  PMM_SERVER_PASSWORD: admin
  PMM_SERVER_API_KEY: apikey

The example above matches what is shipped in deploy/secrets.yaml which contains default passwords and default API key. You should NOT use these in production, but they are present to assist in automated testing or simple use in a development environment.

As you can see, because we use the stringData type when creating the Secrets object, all values for each key/value pair are stated in plain text format convenient from the user’s point of view. But the resulting Secrets object contains passwords stored as data - i.e., base64-encoded strings. If you want to update any field, you’ll need to encode the value into base64 format. To do this, you can run echo -n "password" | base64 --wrap=0 (or just echo -n "password" | base64 in case of Apple macOS) in your local shell to get valid values. For example, setting the Database Admin user’s password to new_password in the my-cluster-name-secrets object can be done with the following command:

in Linuxin macOS

$ kubectl patch secret/my-cluster-name-secrets -p '{"data":{"MONGODB_DATABASE_ADMIN_PASSWORD": "'$(echo -n new_password | base64 --wrap=0)'"}}'

$ kubectl patch secret/my-cluster-name-secrets -p '{"data":{"MONGODB_DATABASE_ADMIN_PASSWORD": "'$(echo -n new_password | base64)'"}}'

Note

The operator creates and updates an additional Secrets object named based on the cluster name, like internal-my-cluster-name-users. It is used only by the Operator and should undergo no manual changes by the user. This object contains secrets with the same passwords as the one specified in spec.secrets.users (e.g. my-cluster-name-secrets). When the user updates my-cluster-name-secrets, the Operator propagates these changes to the internal internal-my-cluster-name-users Secrets object.

Password Rotation Policies and Timing

When there is a change in user secrets, the Operator creates the necessary transaction to change passwords. This rotation happens almost instantly (the delay can be up to a few seconds), and it’s not needed to take any action beyond changing the password.

Note

Please don’t change secrets.users option in CR, make changes inside the secrets object itself.

Development Mode

To make development and testing easier, deploy/secrets.yaml secrets file contains default passwords for MongoDB system users.

These development-mode credentials from deploy/secrets.yaml are:

Secret Key	Secret Value
MONGODB_BACKUP_USER	backup
MONGODB_BACKUP_PASSWORD	backup123456
MONGODB_DATABASE_ADMIN_USER	databaseAdmin
MONGODB_DATABASE_ADMIN_PASSWORD	databaseAdmin123456
MONGODB_CLUSTER_ADMIN_USER	clusterAdmin
MONGODB_CLUSTER_ADMIN_PASSWORD	clusterAdmin123456
MONGODB_CLUSTER_MONITOR_USER	clusterMonitor
MONGODB_CLUSTER_MONITOR_PASSWORD	clusterMonitor123456
MONGODB_USER_ADMIN_USER	userAdmin
MONGODB_USER_ADMIN_PASSWORD	userAdmin123456
PMM_SERVER_USER	admin
PMM_SERVER_PASSWORD	admin
PMM_SERVER_API_KEY	apikey

Warning

Do not use the default MongoDB Users and/or default PMM API key in production!

MongoDB Internal Authentication Key (optional)

Default Secret name: my-cluster-name-mongodb-keyfile

Secret name field: spec.secrets.key

By default, the operator will create a random, 1024-byte key for MongoDB Internal Authentication if it does not already exist. If you would like to deploy a different key, create the secret manually before starting the operator. Example:

apiVersion: v1
kind: Secret
metadata:
  name: my-cluster-name-mongodb-keyfile
type: Opaque
data:
  mongodb-key: <replace-this-value-with-base-64-encoded-text>

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Last update: 2024-11-21