[feature] Change default docker registry in operator command line flags

I can not download docker images from docker.elastic.co in private network eviroment.
So if we could set operator command line flags such as: --default-registry=xxx.xxx.xxx, it would be more convenience to use eck where network can not access internet.

Sounds like a good feature request. Would you mind creating an issue on https://github.com/elastic/cloud-on-k8s?

The workaround so far is to specify the image field in your Elasticsearch, Kibana, APMServer yaml manifest. This doc explains how to create and use your own image.

Issue have submitted.
I knew docker image can be specified, but sometimes would get confused when using image with version field, so if we can specify registry, the yaml config would be more concise.