To run a container in a Kubernetes environment, you should define a YAML manifest for the container and its resources2. YAML manifests are used to define Kubernetes objects, such as pods or services. These manifests describe the desired state of the system2.

The default container runtime engine used by OpenShift is cri-o. CRI-O is an open source, community-driven container engine. Its primary goal is to replace the Docker service as the container engine for Kubernetes implementations, such as OpenShift Container Platform3.

The openstack user list command uses the Keystone service, which is the identity service for OpenStack. Keystone provides authentication, authorization, and service discovery for OpenStack. It also manages projects, users, roles, and endpoints for the OpenStack services