$ oc get scc kubevirt-controller -o yaml
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Security policies
Learn about OpenShift Virtualization security and authorization.
Key points
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OpenShift Virtualization adheres to the
restrictedKubernetes pod security standards profile, which aims to enforce the current best practices for pod security. -
Virtual machine (VM) workloads run as unprivileged pods.
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Security context constraints (SCCs) are defined for the
kubevirt-controllerservice account. -
TLS certificates for OpenShift Virtualization components are renewed and rotated automatically.
About workload security
By default, virtual machine (VM) workloads do not run with root privileges in OpenShift Virtualization, and there are no supported OpenShift Virtualization features that require root privileges.
For each VM, a virt-launcher pod runs an instance of libvirt in session mode to manage the VM process. In session mode, the libvirt daemon runs as a non-root user account and only permits connections from clients that are running under the same user identifier (UID). Therefore, VMs run as unprivileged pods, adhering to the security principle of least privilege.
TLS certificates
TLS certificates for OpenShift Virtualization components are renewed and rotated automatically. You are not required to refresh them manually.
Automatic renewal schedules
TLS certificates are automatically deleted and replaced according to the following schedule:
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KubeVirt certificates are renewed daily.
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Containerized Data Importer controller (CDI) certificates are renewed every 15 days.
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MAC pool certificates are renewed every year.
Automatic TLS certificate rotation does not disrupt any operations. For example, the following operations continue to function without any disruption:
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Migrations
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Image uploads
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VNC and console connections
Authorization
OpenShift Virtualization uses role-based access control (RBAC) to define permissions for human users and service accounts. The permissions defined for service accounts control the actions that OpenShift Virtualization components can perform.
You can also use RBAC roles to manage user access to virtualization features. For example, an administrator can create an RBAC role that provides the permissions required to launch a virtual machine. The administrator can then restrict access by binding the role to specific users.
Default cluster roles for OpenShift Virtualization
By using cluster role aggregation, OpenShift Virtualization extends the default Red Hat OpenShift Service on AWS cluster roles to include permissions for accessing virtualization objects.
| Default cluster role | OpenShift Virtualization cluster role | OpenShift Virtualization cluster role description |
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A user that can view all OpenShift Virtualization resources in the cluster but cannot create, delete, modify, or access them. For example, the user can see that a virtual machine (VM) is running but cannot shut it down or gain access to its console. |
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A user that can modify all OpenShift Virtualization resources in the cluster. For example, the user can create VMs, access VM consoles, and delete VMs. |
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A user that has full permissions to all OpenShift Virtualization resources, including the ability to delete collections of resources. The user can also view and modify the OpenShift Virtualization runtime configuration, which is located in the |
RBAC roles for storage features in OpenShift Virtualization
The following permissions are granted to the Containerized Data Importer (CDI), including the cdi-operator and cdi-controller service accounts.
Cluster-wide RBAC roles
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Allow list: |
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Namespaced RBAC roles
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Additional SCCs and permissions for the kubevirt-controller service account
Security context constraints (SCCs) control permissions for pods. These permissions include actions that a pod, a collection of containers, can perform and what resources it can access. You can use SCCs to define a set of conditions that a pod must run with to be accepted into the system.
The virt-controller is a cluster controller that creates the virt-launcher pods for virtual machines in the cluster. These pods are granted permissions by the kubevirt-controller service account.
The kubevirt-controller service account is granted additional SCCs and Linux capabilities so that it can create virt-launcher pods with the appropriate permissions. These extended permissions allow virtual machines to use OpenShift Virtualization features that are beyond the scope of typical pods.
The kubevirt-controller service account is granted the following SCCs:
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scc.AllowHostDirVolumePlugin = true
This allows virtual machines to use the hostpath volume plugin. -
scc.AllowPrivilegedContainer = false
This ensures the virt-launcher pod is not run as a privileged container. -
scc.AllowedCapabilities = []corev1.Capability{"SYS_NICE", "NET_BIND_SERVICE"}-
SYS_NICEallows setting the CPU affinity. -
NET_BIND_SERVICEallows DHCP and Slirp operations.
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Viewing the SCC and RBAC definitions for the kubevirt-controller
You can view the SecurityContextConstraints definition for the kubevirt-controller by using the oc tool:
You can view the RBAC definition for the kubevirt-controller clusterrole by using the oc tool:
$ oc get clusterrole kubevirt-controller -o yaml