Description of problem:

When Kubernetes Image Puller is enabled with the CheCluster custom resource, it creates the KubernetesImagePuller/devspaces-image-puller instance with a set of recommended workspace-related images that are automatically detected and pre-pulled after installation. Still, the udi-rhel8 image is missing, as well as other images that are usually expected to be used to create a workspace from:

• https://<devspaces-url>/plugin-registry/v3/external_images.txt
• https://<devspaces-url>/devfile-registry/devfiles/external_images.txt

Is there a chance that the DevSpaces Operator can manage the list of all images itself while still being able to add any images manually?

With the ones that mount volumes in the Dockerfile now, it is stated that these for example traefik are not supported for pre-pulling on OpenShift 3.11.

The motivation is to make the administration of multiple clusters easier with the Dev Spaces operator, especially during upgrades. So, automatically upgrade the image list to pre-pull after upgrading Dev Spaces to a new version.  
 
Actual results:
Right now, we have to enable the ImagePuller in the CheCluster CR and manually add the udi-rhel8 image to be pre-pulled as well as other images and manage the list of images after upgrades to check if anything was changed. Also, these images are in the form key=value where the value is an image itself, but it is not clear if the key is used anywhere or if the key is irrelevant.

Expected results:
The only required configuration is to say ImagePuller enabled: true/false. The rest should be processed with the operator while still having the option to change the configuration and list of the images. All documented with examples, and refreshed if there are any changes to the images or if they change only during upgrades and new releases of Dev Spaces.