Image Catalog

ImageCatalog and ClusterImageCatalog are essential resources that empower you to define images for creating a Cluster .

The key distinction lies in their scope: an ImageCatalog is namespaced, while a ClusterImageCatalog is cluster-scoped.

Both share a common structure, comprising a list of images, each equipped with a major field indicating the major version of the image.

Warning

The operator places trust in the user-defined major version and refrains from conducting any PostgreSQL version detection. It falls upon your responsibility to ensure alignment between the declared major version in the catalog and the PostgreSQL image.

The major field’s value must remain unique within a catalog, preventing duplication across images. Distinct catalogs, however, have the flexibility to expose different images under the same major value.

Example of a Namespaced ``ImageCatalog`` :

kind: ImageCatalog
metadata:
  name: postgresql
  namespace: default
spec:
  images:
    - major: 15
      image: ghcr.io/cloudnative-pg/postgresql:15.6
    - major: 16
      image: ghcr.io/cloudnative-pg/postgresql:16.2

Example of a Cluster-Wide Catalog using ``ClusterImageCatalog`` Resource:

apiVersion: postgresql.cnpg.io/v1
kind: ClusterImageCatalog
metadata:
  name: postgresql
spec:
  images:
    - major: 15
      image: ghcr.io/cloudnative-pg/postgresql:15.6
    - major: 16
      image: ghcr.io/cloudnative-pg/postgresql:16.2

A Cluster resource has the flexibility to reference either an ImageCatalog or a ClusterImageCatalog to precisely specify the desired image.

apiVersion: postgresql.cnpg.io/v1
kind: Cluster
metadata:
  name: cluster-example
spec:
  instances: 3
  imageCatalogRef:
    apiGroup: postgresql.cnpg.io
    kind: ImageCatalog
    name: postgresql
    major: 16
  storage:
    size: 1Gi

Clusters utilizing these catalogs maintain continuous monitoring. Any alterations to the images within a catalog trigger automatic updates for all associated clusters referencing that specific entry.