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Users

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.

System Users

Credentials for system users are stored as a Kubernetes Secrets object. The Operator requires to be deployed before PostgreSQL Cluster is started. The name of the required secrets (cluster1-users by default) should be set in the spec.secretsName option of the deploy/cr.yaml configuration file.

The following table shows system users’ names and purposes.

Warning

These users should not be used to run an application.

The default PostgreSQL instance installation via the Percona Operator for PostgreSQL comes with the following users:

Role name Attributes
postgres Superuser, Create role, Create DB, Replication, Bypass RLS
primaryuser Replication
pguser Non-privileged user
pgbouncer Administrative user for the pgBouncer connection pooler

The postgres user will be the admin user for the database instance. The primaryuser is used for replication between primary and replicas. The pguser is the default non-privileged user (you can configure different name of this user in the spec.user Custom Resource option).

YAML Object Format

The default name of the Secrets object for these users is cluster1-users and can be set in the CR for your cluster in spec.secretName to something different. When you create the object yourself, it should match the following simple format:

apiVersion: v1
kind: Secret
metadata:
  name: cluster1-users
type: Opaque
stringData:
  pgbouncer: pgbouncer_password
  postgres: postgres_password
  primaryuser: primaryuser_password
 pguser: pguser_password

The example above matches what is shipped in the deploy/secrets.yaml file.

As you can see, we use the stringData type when creating the Secrets object, so 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 PMM Server user’s password to new_password in the cluster1-users object can be done with the following command:

$ kubectl patch secret/cluster1-users -p '{"data":{"pguser": "'$(echo -n new_password | base64 --wrap=0)'"}}'
$ kubectl patch secret/cluster1-users -p '{"data":{"pguser": "'$(echo -n new_password | base64)'"}}'

Application users

By default you can connect to PostgreSQL as non-privileged pguser user. Also, you can login as postgres (the superuser) to PostgreSQL Pods, but pgBouncer (the connection pooler for PostgreSQL) doesn’t allow postgres user access by default. That’s done for security reasons.

If you still need to provide postgres user access to PostgreSQL instances from the outside, set the pgBouncer.exposePostgresUser option in the deploy/cr.yaml configuration file to true and apply changes as usual by the kubectl apply -f deploy/cr.yaml command.

Note

Allowing superusers to access to the cluster is not recommended.


Last update: 2022-11-03