4.6.2 Blocking Registries

Oracle Container Runtime for Docker provides the option to prevent access to specified registries when attempting to pull container images. This can be used to prevent users from pulling images from specific external registries. This is achieved by setting the block-registry option in /etc/docker/daemon.json.

...
  "block-registry": [
    "docker.io"
  ],
...

You can disable multiple registries by appending the domain or domains you would like to block to the same line:

...
  "block-registry": [
    "docker.io",
    "registry.example.com"
  ],
...

When you have finished editing /etc/docker/daemon.json, restart the Docker Engine service:

# systemctl restart docker