11.6. Adding a pod to an SR-IOV additional network
You can add a pod to an existing Single Root I/O Virtualization (SR-IOV) network.
11.6.1. Runtime configuration for a network attachment
When attaching a pod to an additional network, you can specify a runtime configuration to make specific customizations for the pod. For example, you can request a specific MAC hardware address.
You specify the runtime configuration by setting an annotation in the pod specification. The annotation key is k8s.v1.cni.cncf.io/networks
, and it accepts a JSON object that describes the runtime configuration.
11.6.1.1. Runtime configuration for an Ethernet-based SR-IOV attachment
The following JSON describes the runtime configuration options for an Ethernet-based SR-IOV network attachment.
[ { "name": "<name>", 1 "mac": "<mac_address>", 2 "ips": ["<cidr_range>"] 3 } ]
- 1
- The name of the SR-IOV network attachment definition CR.
- 2
- Optional: The MAC address for the SR-IOV device that is allocated from the resource type defined in the SR-IOV network attachment definition CR. To use this feature, you also must specify
{ "mac": true }
in theSriovNetwork
object. - 3
- Optional: IP addresses for the SR-IOV device that is allocated from the resource type defined in the SR-IOV network attachment definition CR. Both IPv4 and IPv6 addresses are supported. To use this feature, you also must specify
{ "ips": true }
in theSriovNetwork
object.
Example runtime configuration
apiVersion: v1 kind: Pod metadata: name: sample-pod annotations: k8s.v1.cni.cncf.io/networks: |- [ { "name": "net1", "mac": "20:04:0f:f1:88:01", "ips": ["192.168.10.1/24", "2001::1/64"] } ] spec: containers: - name: sample-container image: <image> imagePullPolicy: IfNotPresent command: ["sleep", "infinity"]
11.6.2. Adding a pod to an additional network
You can add a pod to an additional network. The pod continues to send normal cluster-related network traffic over the default network.
When a pod is created additional networks are attached to it. However, if a pod already exists, you cannot attach additional networks to it.
The pod must be in the same namespace as the additional network.
If a network attachment is managed by the SR-IOV Network Operator, the SR-IOV Network Resource Injector adds the resource
field to the Pod
object automatically.
When specifying an SR-IOV hardware network for a Deployment
object or a ReplicationController
object, you must specify the namespace of the NetworkAttachmentDefinition
object. For more information, see the following bugs: BZ#1846333 and BZ#1840962.
Prerequisites
-
Install the OpenShift CLI (
oc
). - Log in to the cluster.
- Install the SR-IOV Operator.
-
Create an
SriovNetwork
object to attach the pod to.
Procedure
Add an annotation to the
Pod
object. Only one of the following annotation formats can be used:To attach an additional network without any customization, add an annotation with the following format. Replace
<network>
with the name of the additional network to associate with the pod:metadata: annotations: k8s.v1.cni.cncf.io/networks: <network>[,<network>,...] 1
- 1
- To specify more than one additional network, separate each network with a comma. Do not include whitespace between the comma. If you specify the same additional network multiple times, that pod will have multiple network interfaces attached to that network.
To attach an additional network with customizations, add an annotation with the following format:
metadata: annotations: k8s.v1.cni.cncf.io/networks: |- [ { "name": "<network>", 1 "namespace": "<namespace>", 2 "default-route": ["<default-route>"] 3 } ]
To create the pod, enter the following command. Replace
<name>
with the name of the pod.$ oc create -f <name>.yaml
Optional: To Confirm that the annotation exists in the
Pod
CR, enter the following command, replacing<name>
with the name of the pod.$ oc get pod <name> -o yaml
In the following example, the
example-pod
pod is attached to thenet1
additional network:$ oc get pod example-pod -o yaml apiVersion: v1 kind: Pod metadata: annotations: k8s.v1.cni.cncf.io/networks: macvlan-bridge k8s.v1.cni.cncf.io/networks-status: |- 1 [{ "name": "openshift-sdn", "interface": "eth0", "ips": [ "10.128.2.14" ], "default": true, "dns": {} },{ "name": "macvlan-bridge", "interface": "net1", "ips": [ "20.2.2.100" ], "mac": "22:2f:60:a5:f8:00", "dns": {} }] name: example-pod namespace: default spec: ... status: ...
- 1
- The
k8s.v1.cni.cncf.io/networks-status
parameter is a JSON array of objects. Each object describes the status of an additional network attached to the pod. The annotation value is stored as a plain text value.
11.6.3. Creating a non-uniform memory access (NUMA) aligned SR-IOV pod
You can create a NUMA aligned SR-IOV pod by restricting SR-IOV and the CPU resources allocated from the same NUMA node with restricted
or single-numa-node
Topology Manager polices.
Prerequisites
-
Install the OpenShift CLI (
oc
). -
Enable a LatencySensitive profile and configure the CPU Manager policy to
static
.
Procedure
Create the following SR-IOV pod spec, and then save the YAML in the
<name>-sriov-pod.yaml
file. Replace<name>
with a name for this pod.The following example shows an SR-IOV pod spec:
apiVersion: v1 kind: Pod metadata: name: sample-pod annotations: k8s.v1.cni.cncf.io/networks: <name> 1 spec: containers: - name: sample-container image: <image> 2 command: ["sleep", "infinity"] resources: limits: memory: "1Gi" 3 cpu: "2" 4 requests: memory: "1Gi" cpu: "2"
- 1
- Replace
<name>
with the name of the SR-IOV network attachment definition CR. - 2
- Replace
<image>
with the name of thesample-pod
image. - 3
- To create the SR-IOV pod with guaranteed QoS, set
memory limits
equal tomemory requests
. - 4
- To create the SR-IOV pod with guaranteed QoS, set
cpu limits
equals tocpu requests
.
Create the sample SR-IOV pod by running the following command:
$ oc create -f <filename> 1
- 1
- Replace
<filename>
with the name of the file you created in the previous step.
Confirm that the
sample-pod
is configured with guaranteed QoS.$ oc describe pod sample-pod
Confirm that the
sample-pod
is allocated with exclusive CPUs.$ oc exec sample-pod -- cat /sys/fs/cgroup/cpuset/cpuset.cpus
Confirm that the SR-IOV device and CPUs that are allocated for the
sample-pod
are on the same NUMA node.$ oc exec sample-pod -- cat /sys/fs/cgroup/cpuset/cpuset.cpus