[User feedback](https://gitlab.com/gitlab-org/gitlab/-/issues/441214) received indicates that they want to be able to run workspaces which are created from private container registries. While there is a work-around it is not [reliable](https://gitlab.com/gitlab-org/gitlab/-/issues/441214#note_1904640957). Providing first-class for private container registry should be considered table stakes for ~"Category:Workspaces" . There are many different container registries used by organizations(e.g. GitLab, DockerHub, AWS ECR, GCR, ACR, etc.). Users generally configure their Kubernetes clusters with the image pull secrets that are needed. So we will build on top of that i.e. users are expected to create the image pull secrets in their Kubernetes cluster and then provide the reference to these secrets while setting up the agent. All workspaces created from the agent would be configured to use these image pull secrets.