Configuring an SR-IOV Ethernet network attachment - Hardware networks | Networking

Ethernet device configuration object
- Configuration of IP address assignment for an additional network
Configuring SR-IOV additional network
Next steps
Additional resources

You can configure an Ethernet network attachment for an Single Root I/O Virtualization (SR-IOV) device in the cluster.

Ethernet device configuration object

You can configure an Ethernet network device by defining an SriovNetwork object.

The following YAML describes an SriovNetwork object:

apiVersion: sriovnetwork.openshift.io/v1
kind: SriovNetwork
metadata:
  name: <name> (1)
  namespace: openshift-sriov-network-operator (2)
spec:
  resourceName: <sriov_resource_name> (3)
  networkNamespace: <target_namespace> (4)
  vlan: <vlan> (5)
  spoofChk: "<spoof_check>" (6)
  ipam: |- (7)
    {}
  linkState: <link_state> (8)
  maxTxRate: <max_tx_rate> (9)
  minTxRate: <min_tx_rate> (10)
  vlanQoS: <vlan_qos> (11)
  trust: "<trust_vf>" (12)
  capabilities: <capabilities> (13)

1 A name for the object. The SR-IOV Network Operator creates a NetworkAttachmentDefinition object with same name.

2 The namespace where the SR-IOV Network Operator is installed.

3 The value for the spec.resourceName parameter from the SriovNetworkNodePolicy object that defines the SR-IOV hardware for this additional network.

4 The target namespace for the SriovNetwork object. Only pods in the target namespace can attach to the additional network.

5 Optional: A Virtual LAN (VLAN) ID for the additional network. The integer value must be from 0 to 4095. The default value is 0.

Optional: The spoof check mode of the VF. The allowed values are the strings "on" and "off".

You must enclose the value you specify in quotes or the object is rejected by the SR-IOV Network Operator.

7 A configuration object for the IPAM CNI plugin as a YAML block scalar. The plugin manages IP address assignment for the attachment definition.

8 Optional: The link state of virtual function (VF). Allowed value are enable, disable and auto.

9 Optional: A maximum transmission rate, in Mbps, for the VF.

Optional: A minimum transmission rate, in Mbps, for the VF. This value must be less than or equal to the maximum transmission rate.

Intel NICs do not support the minTxRate parameter. For more information, see BZ#1772847.

11 Optional: An IEEE 802.1p priority level for the VF. The default value is 0.

Optional: The trust mode of the VF. The allowed values are the strings "on" and "off".

You must enclose the value that you specify in quotes, or the SR-IOV Network Operator rejects the object.

13 Optional: The capabilities to configure for this additional network. You can specify "{ "ips": true }" to enable IP address support or "{ "mac": true }" to enable MAC address support.

Configuration of IP address assignment for an additional network

The IP address management (IPAM) Container Network Interface (CNI) plugin provides IP addresses for other CNI plugins.

You can use the following IP address assignment types:

Static assignment.
Dynamic assignment through a DHCP server. The DHCP server you specify must be reachable from the additional network.
Dynamic assignment through the Whereabouts IPAM CNI plugin.

Static IP address assignment configuration

The following table describes the configuration for static IP address assignment:

Table 1. `ipam` static configuration object
Field	Type	Description
`type`	`string`	The IPAM address type. The value `static` is required.
`addresses`	`array`	An array of objects specifying IP addresses to assign to the virtual interface. Both IPv4 and IPv6 IP addresses are supported.
`routes`	`array`	An array of objects specifying routes to configure inside the pod.
`dns`	`array`	Optional: An array of objects specifying the DNS configuration.

The addresses array requires objects with the following fields:

Table 2. `ipam.addresses[]` array
Field	Type	Description
`address`	`string`	An IP address and network prefix that you specify. For example, if you specify `10.10.21.10/24`, then the additional network is assigned an IP address of `10.10.21.10` and the netmask is `255.255.255.0`.
`gateway`	`string`	The default gateway to route egress network traffic to.

Table 3. `ipam.routes[]` array
Field	Type	Description
`dst`	`string`	The IP address range in CIDR format, such as `192.168.17.0/24` or `0.0.0.0/0` for the default route.
`gw`	`string`	The gateway where network traffic is routed.

Table 4. `ipam.dns` object
Field	Type	Description
`nameservers`	`array`	An array of one or more IP addresses for to send DNS queries to.
`domain`	`array`	The default domain to append to a hostname. For example, if the domain is set to `example.com`, a DNS lookup query for `example-host` is rewritten as `example-host.example.com`.
`search`	`array`	An array of domain names to append to an unqualified hostname, such as `example-host`, during a DNS lookup query.

Static IP address assignment configuration example

{
  "ipam": {
    "type": "static",
      "addresses": [
        {
          "address": "191.168.1.7/24"
        }
      ]
  }
}

Dynamic IP address (DHCP) assignment configuration

The following JSON describes the configuration for dynamic IP address address assignment with DHCP.

Renewal of DHCP leases

A pod obtains its original DHCP lease when it is created. The lease must be periodically renewed by a minimal DHCP server deployment running on the cluster.

The SR-IOV Network Operator does not create a DHCP server deployment; The Cluster Network Operator is responsible for creating the minimal DHCP server deployment.

To trigger the deployment of the DHCP server, you must create a shim network attachment by editing the Cluster Network Operator configuration, as in the following example:

Example shim network attachment definition

apiVersion: operator.openshift.io/v1
kind: Network
metadata:
  name: cluster
spec:
  additionalNetworks:
  - name: dhcp-shim
    namespace: default
    type: Raw
    rawCNIConfig: |-
      {
        "name": "dhcp-shim",
        "cniVersion": "0.3.1",
        "type": "bridge",
        "ipam": {
          "type": "dhcp"
        }
      }
  # ...

Table 5. `ipam` DHCP configuration object
Field	Type	Description
`type`	`string`	The IPAM address type. The value `dhcp` is required.

Dynamic IP address (DHCP) assignment configuration example

{
  "ipam": {
    "type": "dhcp"
  }
}

Dynamic IP address assignment configuration with Whereabouts

The Whereabouts CNI plugin allows the dynamic assignment of an IP address to an additional network without the use of a DHCP server.

The following table describes the configuration for dynamic IP address assignment with Whereabouts:

Table 6. `ipam` whereabouts configuration object
Field	Type	Description
`type`	`string`	The IPAM address type. The value `whereabouts` is required.
`range`	`string`	An IP address and range in CIDR notation. IP addresses are assigned from within this range of addresses.
`exclude`	`array`	Optional: A list of zero or more IP addresses and ranges in CIDR notation. IP addresses within an excluded address range are not assigned.

Dynamic IP address assignment configuration example that uses Whereabouts

{
  "ipam": {
    "type": "whereabouts",
    "range": "192.0.2.192/27",
    "exclude": [
       "192.0.2.192/30",
       "192.0.2.196/32"
    ]
  }
}

Creating a Whereabouts reconciler daemon set

The Whereabouts reconciler is responsible for managing dynamic IP address assignments for the pods within a cluster using the Whereabouts IP Address Management (IPAM) solution. It ensures that each pods gets a unique IP address from the specified IP address range. It also handles IP address releases when pods are deleted or scaled down.

You can also use a NetworkAttachmentDefinition custom resource for dynamic IP address assignment.

The Whereabouts reconciler daemon set is automatically created when you configure an additional network through the Cluster Network Operator. It is not automatically created when you configure an additional network from a YAML manifest.

To trigger the deployment of the Whereabouts reconciler daemonset, you must manually create a whereabouts-shim network attachment by editing the Cluster Network Operator custom resource file.

Use the following procedure to deploy the Whereabouts reconciler daemonset.

Procedure

Edit the Network.operator.openshift.io custom resource (CR) by running the following command:
```
$ oc edit network.operator.openshift.io cluster
```

Modify the additionalNetworks parameter in the CR to add the whereabouts-shim network attachment definition. For example:

apiVersion: operator.openshift.io/v1
kind: Network
metadata:
  name: cluster
spec:
  additionalNetworks:
  - name: whereabouts-shim
    namespace: default
    rawCNIConfig: |-
      {
       "name": "whereabouts-shim",
       "cniVersion": "0.3.1",
       "type": "bridge",
       "ipam": {
         "type": "whereabouts"
       }
      }
    type: Raw

Save the file and exit the text editor.

Verify that the whereabouts-reconciler daemon set deployed successfully by running the following command:

$ oc get all -n openshift-multus | grep whereabouts-reconciler

Example output

pod/whereabouts-reconciler-jnp6g 1/1 Running 0 6s
pod/whereabouts-reconciler-k76gg 1/1 Running 0 6s
pod/whereabouts-reconciler-k86t9 1/1 Running 0 6s
pod/whereabouts-reconciler-p4sxw 1/1 Running 0 6s
pod/whereabouts-reconciler-rvfdv 1/1 Running 0 6s
pod/whereabouts-reconciler-svzw9 1/1 Running 0 6s
daemonset.apps/whereabouts-reconciler 6 6 6 6 6 kubernetes.io/os=linux 6s

Configuring SR-IOV additional network

You can configure an additional network that uses SR-IOV hardware by creating an SriovNetwork object. When you create an SriovNetwork object, the SR-IOV Network Operator automatically creates a NetworkAttachmentDefinition object.

Do not modify or delete an SriovNetwork object if it is attached to any pods in a running state.

Prerequisites

Install the OpenShift CLI (oc).
Log in as a user with cluster-admin privileges.

Procedure

Create a SriovNetwork object, and then save the YAML in the <name>.yaml file, where <name> is a name for this additional network. The object specification might resemble the following example:

apiVersion: sriovnetwork.openshift.io/v1
kind: SriovNetwork
metadata:
  name: attach1
  namespace: openshift-sriov-network-operator
spec:
  resourceName: net1
  networkNamespace: project2
  ipam: |-
    {
      "type": "host-local",
      "subnet": "10.56.217.0/24",
      "rangeStart": "10.56.217.171",
      "rangeEnd": "10.56.217.181",
      "gateway": "10.56.217.1"
    }

To create the object, enter the following command:
```
$ oc create -f <name>.yaml
```
where <name> specifies the name of the additional network.
Optional: To confirm that the NetworkAttachmentDefinition object that is associated with the SriovNetwork object that you created in the previous step exists, enter the following command. Replace <namespace> with the networkNamespace you specified in the SriovNetwork object.
```
$ oc get net-attach-def -n <namespace>
```

Next steps

Adding a pod to an SR-IOV additional network

Additional resources

Configuring an SR-IOV network device