Kubernetes - Registry Security Practices

Images from the internal registry that are no longer required by the system due to age, status, or exceed limits are automatically pruned. Cluster administrators can configure the Pruning Custom Resource, or suspend it.

For more information on configuring the ImagePruner, consult the OpenShift documentation: https://access.redhat.com/documentation/en-us/openshift_container_platform/latest/html/building_applications/pruning-objects

The configuration imagestream.spec.tags.importPolicy.scheduled determines whether the imagestream is configured to periodically check for updates. This is useful when working with an external container image registry, to periodically re-import an image, for example to get latest security updates.

You can set the scheduled update by calling:

$ oc patch imagestream NAME -n NAMESPACE --type merge -p '{"spec":{"tags":[{"name":"TAG_NAME","importPolicy":{"scheduled":true}}]}}'

For more information, follow the ImageStreams documentation

oc patch

/tmp/allowed-registries-patch.yaml

spec:
  registrySources:
    allowedRegistries:
    - my-trusted-registry.internal.example.com

oc patch image.config.openshift.io cluster --patch="$(cat /tmp/allowed-registries-patch.yaml)" --type=merge

oc patch

/tmp/allowed-import-registries-patch.yaml

spec:
  allowedRegistriesForImport:
  - domainName: my-trusted-registry.internal.example.com
    insecure: false

oc patch image.config.openshift.io cluster --patch="$(cat /tmp/allowed-import-registries-patch.yaml)" --type=merge

oc get image.config.openshift.io/cluster -o json | jq '.spec | (.allowedRegistriesForImport[])? | select(.insecure==true)'

oc edit image.config.openshift.io/cluster

oc patch image.config.openshift.io cluster --type=json -p "[{'op': 'remove', 'path': '/spec/registrySources/insecureRegistries'}]"