PostgreSQL Operator

The Postgres operator manages PostgreSQL clusters on Kubernetes (K8s):

  1. The operator watches additions, updates, and deletions of PostgreSQL cluster manifests and changes the running clusters accordingly. For example, when a user submits a new manifest, the operator fetches that manifest and spawns a new Postgres cluster along with all necessary entities such as K8s StatefulSets and Postgres roles. See this Postgres cluster manifest for settings that a manifest may contain.
  2. The operator also watches updates to its own configuration and alters running Postgres clusters if necessary. For instance, if the Docker image in a pod is changed, the operator carries out the rolling update, which means it re-spawns pods of each managed StatefulSet one-by-one with the new Docker image.
  3. Finally, the operator periodically synchronizes the actual state of each Postgres cluster with the desired state defined in the cluster's manifest.
  4. The operator aims to be hands free as configuration works only via manifests. This enables easy integration in automated deploy pipelines with no access to K8s directly.

— postgres-operator.readthedocs.io

In the Shivering-Isles Infrastructure the Zalando Postgres Operator is used to manage highly available database clusters for all applciations. Takes away a lot of the common pain points for applications, such as postgresql updates, and standardises backups using point-in-time recovery as well as monitoring.