Configuring the SR-IOV Network Operator

The Single Root I/O Virtualization (SR-IOV) Network Operator manages the SR-IOV network devices and network attachments in your cluster.

Configuring the SR-IOV Network Operator

Modifying the SR-IOV Network Operator configuration is not normally necessary. The default configuration is recommended for most use cases. Complete the steps to modify the relevant configuration only if the default behavior of the Operator is not compatible with your use case.

The SR-IOV Network Operator adds the SriovOperatorConfig.sriovnetwork.openshift.io CustomResourceDefinition resource. The Operator automatically creates a SriovOperatorConfig custom resource (CR) named default in the openshift-sriov-network-operator namespace.

The default CR contains the SR-IOV Network Operator configuration for your cluster. To change the Operator configuration, you must modify this CR.

SR-IOV Network Operator config custom resource

The fields for the sriovoperatorconfig custom resource are described in the following table:

Table 1. SR-IOV Network Operator config custom resource
FieldTypeDescription

metadata.name

string

Specifies the name of the SR-IOV Network Operator instance. The default value is default. Do not set a different value.

metadata.namespace

string

Specifies the namespace of the SR-IOV Network Operator instance. The default value is openshift-sriov-network-operator. Do not set a different value.

spec.configDaemonNodeSelector

string

Specifies the node selection to control scheduling the SR-IOV Network Config Daemon on selected nodes. By default, this field is not set and the Operator deploys the SR-IOV Network Config daemon set on worker nodes.

spec.disableDrain

boolean

Specifies whether to disable the node draining process or enable the node draining process when you apply a new policy to configure the NIC on a node. Setting this field to true facilitates software development and installing OKD on a single node. By default, this field is not set.

For single-node clusters, set this field to true after installing the Operator. This field must remain set to true.

spec.enableInjector

boolean

Specifies whether to enable or disable the Network Resources Injector daemon set. By default, this field is set to true.

spec.enableOperatorWebhook

boolean

Specifies whether to enable or disable the Operator Admission Controller webhook daemon set. By default, this field is set to true.

spec.logLevel

integer

Specifies the log verbosity level of the Operator. Set to 0 to show only the basic logs. Set to 2 to show all the available logs. By default, this field is set to 2.

About the Network Resources Injector

The Network Resources Injector is a Kubernetes Dynamic Admission Controller application. It provides the following capabilities:

  • Mutation of resource requests and limits in a pod specification to add an SR-IOV resource name according to an SR-IOV network attachment definition annotation.

  • Mutation of a pod specification with a Downward API volume to expose pod annotations, labels, and huge pages requests and limits. Containers that run in the pod can access the exposed information as files under the /etc/podnetinfo path.

By default, the Network Resources Injector is enabled by the SR-IOV Network Operator and runs as a daemon set on all control plane nodes. The following is an example of Network Resources Injector pods running in a cluster with three control plane nodes:

  1. $ oc get pods -n openshift-sriov-network-operator

Example output

  1. NAME                                      READY   STATUS    RESTARTS   AGE
  2. network-resources-injector-5cz5p          1/1     Running   0          10m
  3. network-resources-injector-dwqpx          1/1     Running   0          10m
  4. network-resources-injector-lktz5          1/1     Running   0          10m

About the SR-IOV Network Operator admission controller webhook

The SR-IOV Network Operator Admission Controller webhook is a Kubernetes Dynamic Admission Controller application. It provides the following capabilities:

  • Validation of the SriovNetworkNodePolicy CR when it is created or updated.

  • Mutation of the SriovNetworkNodePolicy CR by setting the default value for the priority and deviceType fields when the CR is created or updated.

By default the SR-IOV Network Operator Admission Controller webhook is enabled by the Operator and runs as a daemon set on all control plane nodes.

Use caution when disabling the SR-IOV Network Operator Admission Controller webhook. You can disable the webhook under specific circumstances, such as troubleshooting, or if you want to use unsupported devices.

The following is an example of the Operator Admission Controller webhook pods running in a cluster with three control plane nodes:

  1. $ oc get pods -n openshift-sriov-network-operator

Example output

  1. NAME                                      READY   STATUS    RESTARTS   AGE
  2. operator-webhook-9jkw6                    1/1     Running   0          16m
  3. operator-webhook-kbr5p                    1/1     Running   0          16m
  4. operator-webhook-rpfrl                    1/1     Running   0          16m

About custom node selectors

The SR-IOV Network Config daemon discovers and configures the SR-IOV network devices on cluster nodes. By default, it is deployed to all the worker nodes in the cluster. You can use node labels to specify on which nodes the SR-IOV Network Config daemon runs.

Disabling or enabling the Network Resources Injector

To disable or enable the Network Resources Injector, which is enabled by default, complete the following procedure.

Prerequisites

  • Install the OpenShift CLI (oc).

  • Log in as a user with cluster-admin privileges.

  • You must have installed the SR-IOV Network Operator.

Procedure

  • Set the enableInjector field. Replace <value> with false to disable the feature or true to enable the feature.

    1. $ oc patch sriovoperatorconfig default \
    2.   --type=merge -n openshift-sriov-network-operator \
    3.   --patch '{ "spec": { "enableInjector": <value> } }'

    You can alternatively apply the following YAML to update the Operator:

    1. apiVersion: sriovnetwork.openshift.io/v1
    2. kind: SriovOperatorConfig
    3. metadata:
    4.   name: default
    5.   namespace: openshift-sriov-network-operator
    6. spec:
    7.   enableInjector: <value>

Disabling or enabling the SR-IOV Network Operator admission controller webhook

To disable or enable the admission controller webhook, which is enabled by default, complete the following procedure.

Prerequisites

  • Install the OpenShift CLI (oc).

  • Log in as a user with cluster-admin privileges.

  • You must have installed the SR-IOV Network Operator.

Procedure

  • Set the enableOperatorWebhook field. Replace <value> with false to disable the feature or true to enable it:

    1. $ oc patch sriovoperatorconfig default --type=merge \
    2.   -n openshift-sriov-network-operator \
    3.   --patch '{ "spec": { "enableOperatorWebhook": <value> } }'

    You can alternatively apply the following YAML to update the Operator:

    1. apiVersion: sriovnetwork.openshift.io/v1
    2. kind: SriovOperatorConfig
    3. metadata:
    4.   name: default
    5.   namespace: openshift-sriov-network-operator
    6. spec:
    7.   enableOperatorWebhook: <value>

Configuring a custom NodeSelector for the SR-IOV Network Config daemon

The SR-IOV Network Config daemon discovers and configures the SR-IOV network devices on cluster nodes. By default, it is deployed to all the worker nodes in the cluster. You can use node labels to specify on which nodes the SR-IOV Network Config daemon runs.

To specify the nodes where the SR-IOV Network Config daemon is deployed, complete the following procedure.

When you update the configDaemonNodeSelector field, the SR-IOV Network Config daemon is recreated on each selected node. While the daemon is recreated, cluster users are unable to apply any new SR-IOV Network node policy or create new SR-IOV pods.

Procedure

  • To update the node selector for the operator, enter the following command:

    1. $ oc patch sriovoperatorconfig default --type=json \
    2.   -n openshift-sriov-network-operator \
    3.   --patch '[{
    4.       "op": "replace",
    5.       "path": "/spec/configDaemonNodeSelector",
    6.       "value": {<node_label>}
    7.     }]'

    Replace <node_label> with a label to apply as in the following example: "node-role.kubernetes.io/worker": "".

    You can alternatively apply the following YAML to update the Operator:

    1. apiVersion: sriovnetwork.openshift.io/v1
    2. kind: SriovOperatorConfig
    3. metadata:
    4.   name: default
    5.   namespace: openshift-sriov-network-operator
    6. spec:
    7.   configDaemonNodeSelector:
    8.     <node_label>

Configuring the SR-IOV Network Operator for single node installations

By default, the SR-IOV Network Operator drains workloads from a node before every policy change. The Operator performs this action to ensure that there no workloads using the virtual functions before the reconfiguration.

For installations on a single node, there are no other nodes to receive the workloads. As a result, the Operator must be configured not to drain the workloads from the single node.

After performing the following procedure to disable draining workloads, you must remove any workload that uses an SR-IOV network interface before you change any SR-IOV network node policy.

Prerequisites

  • Install the OpenShift CLI (oc).

  • Log in as a user with cluster-admin privileges.

  • You must have installed the SR-IOV Network Operator.

Procedure

  • To set the disableDrain field to true, enter the following command:

    1. $ oc patch sriovoperatorconfig default --type=merge \
    2.   -n openshift-sriov-network-operator \
    3.   --patch '{ "spec": { "disableDrain": true } }'

    You can alternatively apply the following YAML to update the Operator:

    1. apiVersion: sriovnetwork.openshift.io/v1
    2. kind: SriovOperatorConfig
    3. metadata:
    4.   name: default
    5.   namespace: openshift-sriov-network-operator
    6. spec:
    7.   disableDrain: true

Deploying the SR-IOV Operator for hosted control planes

Hosted control planes is a Technology Preview feature only. Technology Preview features are not supported with Red Hat production service level agreements (SLAs) and might not be functionally complete. Red Hat does not recommend using them in production. These features provide early access to upcoming product features, enabling customers to test functionality and provide feedback during the development process.

For more information about the support scope of Red Hat Technology Preview features, see Technology Preview Features Support Scope.

After you configure and deploy your hosting service cluster, you can create a subscription to the SR-IOV Operator on a hosted cluster. The SR-IOV pod runs on worker machines rather than the control plane.

Prerequisites

You have configured and deployed the hosted cluster.

Procedure

  1. Create a namespace and an Operator group:

    1. apiVersion: v1
    2. kind: Namespace
    3. metadata:
    4.   name: openshift-sriov-network-operator
    5. ---
    6. apiVersion: operators.coreos.com/v1
    7. kind: OperatorGroup
    8. metadata:
    9.   name: sriov-network-operators
    10.   namespace: openshift-sriov-network-operator
    11. spec:
    12.   targetNamespaces:
    13.   - openshift-sriov-network-operator

  2. Create a subscription to the SR-IOV Operator:

    1. apiVersion: operators.coreos.com/v1alpha1
    2. kind: Subscription
    3. metadata:
    4.   name: sriov-network-operator-subsription
    5.   namespace: openshift-sriov-network-operator
    6. spec:
    7.   channel: "4.13"
    8.   name: sriov-network-operator
    9.   config:
    10.     nodeSelector:
    11.       node-role.kubernetes.io/worker: ""
    12.   source: s/qe-app-registry/redhat-operators
    13.   sourceNamespace: openshift-marketplace

Verification

  1. To verify that the SR-IOV Operator is ready, run the following command and view the resulting output:

    1. $ oc get csv -n openshift-sriov-network-operator

    Example output

    1. NAME                                         DISPLAY                   VERSION               REPLACES                                     PHASE
    2. sriov-network-operator.4.13.0-202211021237   SR-IOV Network Operator   4.13.0-202211021237   sriov-network-operator.4.13.0-202210290517   Succeeded

  2. To verify that the SR-IOV pods are deployed, run the following command:

    1. $ oc get pods -n openshift-sriov-network-operator

Next steps