SupportConsoleDevelopersStart a trialContact

Chapter 24. Kubernetes NMState

24.1. Observing and updating the node network state and configuration

After you install the Kubernetes NMState Operator, you can use the Operator to observe and update your cluster’s node network state and network configuration.

For more information about how to install the NMState Operator, see Kubernetes NMState Operator.

24.1.1. Viewing the network state of a node by using the CLI

Node network state is the network configuration for all nodes in the cluster. A NodeNetworkState object exists on every node in the cluster. This object is periodically updated and captures the state of the network for that node.

Procedure

  1. List all the NodeNetworkState objects in the cluster: 

    $ oc get nns

  2. Inspect a NodeNetworkState object to view the network on that node. The output in this example has been redacted for clarity: 

    $ oc get nns node01 -o yaml

    Example output

    apiVersion: nmstate.io/v1
kind: NodeNetworkState
metadata:
  name: node01 1
status:
  currentState: 2
    dns-resolver:
# ...
    interfaces:
# ...
    route-rules:
# ...
    routes:
# ...
  lastSuccessfulUpdateTime: "2020-01-31T12:14:00Z" 3

    1
    The name of the NodeNetworkState object is taken from the node.
    2
    The currentState contains the complete network configuration for the node, including DNS, interfaces, and routes.
    3
    Timestamp of the last successful update. This is updated periodically as long as the node is reachable and can be used to evalute the freshness of the report.

24.1.2. Viewing the network state of a node from the web console

As an administrator, you can use the OpenShift Container Platform web console to observe NodeNetworkState resources and network interfaces, and access network details.

Procedure

  1. Navigate to Networking NodeNetworkState.

    In the NodeNetworkState page, you can view the list of NodeNetworkState resources and the corresponding interfaces that are created on the nodes. You can use Filter based on Interface state, Interface type, and IP, or the search bar based on criteria Name or Label, to narrow down the displayed NodeNetworkState resources.

  2. To access the detailed information about NodeNetworkState resource, click the NodeNetworkState resource name listed in the Name column .
  3. to expand and view the Network Details section for the NodeNetworkState resource, click the > icon . Alternatively, you can click on each interface type under the Network interface column to view the network details.

24.1.3. Managing policy from the web console

You can update the node network configuration, such as adding or removing interfaces from nodes, by applying NodeNetworkConfigurationPolicy manifests to the cluster. Manage the policy from the web console by accessing the list of created policies in the NodeNetworkConfigurationPolicy page under the Networking menu. This page enables you to create, update, monitor, and delete the policies.

24.1.3.1. Monitoring the policy status

You can monitor the policy status from the NodeNetworkConfigurationPolicy page. This page displays all the policies created in the cluster in a tabular format, with the following columns:

Name
The name of the policy created.
Matched nodes
The count of nodes where the policies are applied. This could be either a subset of nodes based on the node selector or all the nodes on the cluster.
Node network state
The enactment state of the matched nodes. You can click on the enactment state and view detailed information on the status.

To find the desired policy, you can filter the list either based on enactment state by using the Filter option, or by using the search option.

24.1.3.2. Creating a policy

You can create a policy by using either a form or YAML in the web console.

Procedure

  1. Navigate to Networking NodeNetworkConfigurationPolicy.

  2. In the NodeNetworkConfigurationPolicy page, click Create, and select From Form option.

    In case there are no existing policies, you can alternatively click Create NodeNetworkConfigurationPolicy to createa policy using form.

    Note

    To create policy using YAML, click Create, and select With YAML option. The following steps are applicable to create a policy only by using form.

  3. Optional: Check the Apply this NodeNetworkConfigurationPolicy only to specific subsets of nodes using the node selector checkbox to specify the nodes where the policy must be applied.
  4. Enter the policy name in the Policy name field.
  5. Optional: Enter the description of the policy in the Description field.

  6. Optional: In the Policy Interface(s) section, a bridge interface is added by default with preset values in editable fields. Edit the values by executing the following steps:

    1. Enter the name of the interface in Interface name field.
    2. Select the network state from Network state dropdown. The default selected value is Up.

    3. Select the type of interface from Type dropdown. The available values are Bridge, Bonding, and Ethernet. The default selected value is Bridge.

      Note

      Addition of a VLAN interface by using the form is not supported. To add a VLAN interface, you must use YAML to create the policy. Once added, you cannot edit the policy by using form.

    4. Optional: In the IP configuration section, check IPv4 checkbox to assign an IPv4 address to the interface, and configure the IP address assignment details:

      1. Click IP address to configure the interface with a static IP address, or DHCP to auto-assign an IP address.

      2. If you have selected IP address option, enter the IPv4 address in IPV4 address field, and enter the prefix length in Prefix length field.

        If you have selected DHCP option, uncheck the options that you want to disable. The available options are Auto-DNS, Auto-routes, and Auto-gateway. All the options are selected by default.

    5. Optional: Enter the port number in Port field.
    6. Optional: Check the checkbox Enable STP to enable STP.
    7. Optional: To add an interface to the policy, click Add another interface to the policy.
    8. Optional: To remove an interface from the policy, click icon next to the interface.
    Note

    Alternatively, you can click Edit YAML on the top of the page to continue editing the form using YAML.

  7. Click Create to complete policy creation.

24.1.3.3. Updating the policy

24.1.3.3.1. Updating the policy by using form

Procedure

  1. Navigate to Networking NodeNetworkConfigurationPolicy.
  2. In the NodeNetworkConfigurationPolicy page, click the kebab icon placed next to the policy you want to edit, and click Edit.
  3. Edit the fields that you want to update.
  4. Click Save.
Note

Addition of a VLAN interface using the form is not supported. To add a VLAN interface, you must use YAML to create the policy. Once added, you cannot edit the policy using form.

24.1.3.3.2. Updating the policy by using YAML

Procedure

  1. Navigate to Networking NodeNetworkConfigurationPolicy.
  2. In the NodeNetworkConfigurationPolicy page, click the policy name under the Name column for the policy you want to edit.
  3. Click the YAML tab, and edit the YAML.
  4. Click Save.

24.1.3.4. Deleting the policy

Procedure

  1. Navigate to Networking NodeNetworkConfigurationPolicy.
  2. In the NodeNetworkConfigurationPolicy page, click the kebab icon placed next to the policy you want to delete, and click Delete.
  3. In the pop-up window, enter the policy name to confirm deletion, and click Delete.

24.1.4. Managing policy by using the CLI

24.1.4.1. Creating an interface on nodes

Create an interface on nodes in the cluster by applying a NodeNetworkConfigurationPolicy manifest to the cluster. The manifest details the requested configuration for the interface.

By default, the manifest applies to all nodes in the cluster. To add the interface to specific nodes, add the spec: nodeSelector parameter and the appropriate <key>:<value> for your node selector.

You can configure multiple nmstate-enabled nodes concurrently. The configuration applies to 50% of the nodes in parallel. This strategy prevents the entire cluster from being unavailable if the network connection fails. To apply the policy configuration in parallel to a specific portion of the cluster, use the maxUnavailable field.

Procedure

  1. Create the NodeNetworkConfigurationPolicy manifest. The following example configures a Linux bridge on all worker nodes and configures the DNS resolver: 

    apiVersion: nmstate.io/v1
kind: NodeNetworkConfigurationPolicy
metadata:
  name: br1-eth1-policy 1
spec:
  nodeSelector: 2
    node-role.kubernetes.io/worker: "" 3
  maxUnavailable: 3 4
  desiredState:
    interfaces:
      - name: br1
        description: Linux bridge with eth1 as a port 5
        type: linux-bridge
        state: up
        ipv4:
          dhcp: true
          enabled: true
          auto-dns: false
        bridge:
          options:
            stp:
              enabled: false
          port:
            - name: eth1
    dns-resolver: 6
      config:
        search:
        - example.com
        - example.org
        server:
        - 8.8.8.8
    1
    Name of the policy.
    2
    Optional: If you do not include the nodeSelector parameter, the policy applies to all nodes in the cluster.
    3
    This example uses the node-role.kubernetes.io/worker: "" node selector to select all worker nodes in the cluster.
    4
    Optional: Specifies the maximum number of nmstate-enabled nodes that the policy configuration can be applied to concurrently. This parameter can be set to either a percentage value (string), for example, "10%", or an absolute value (number), such as 3.
    5
    Optional: Human-readable description for the interface.
    6
    Optional: Specifies the search and server settings for the DNS server.

  2. Create the node network policy: 

    $ oc apply -f br1-eth1-policy.yaml 1
    1
    File name of the node network configuration policy manifest.

Additional resources

24.1.4.2. Confirming node network policy updates on nodes

A NodeNetworkConfigurationPolicy manifest describes your requested network configuration for nodes in the cluster. The node network policy includes your requested network configuration and the status of execution of the policy on the cluster as a whole.

When you apply a node network policy, a NodeNetworkConfigurationEnactment object is created for every node in the cluster. The node network configuration enactment is a read-only object that represents the status of execution of the policy on that node. If the policy fails to be applied on the node, the enactment for that node includes a traceback for troubleshooting.

Procedure

  1. To confirm that a policy has been applied to the cluster, list the policies and their status: 

    $ oc get nncp

  2. Optional: If a policy is taking longer than expected to successfully configure, you can inspect the requested state and status conditions of a particular policy: 

    $ oc get nncp <policy> -o yaml

  3. Optional: If a policy is taking longer than expected to successfully configure on all nodes, you can list the status of the enactments on the cluster: 

    $ oc get nnce

  4. Optional: To view the configuration of a particular enactment, including any error reporting for a failed configuration: 

    $ oc get nnce <node>.<policy> -o yaml

24.1.4.3. Removing an interface from nodes

You can remove an interface from one or more nodes in the cluster by editing the NodeNetworkConfigurationPolicy object and setting the state of the interface to absent.

Removing an interface from a node does not automatically restore the node network configuration to a previous state. If you want to restore the previous state, you will need to define that node network configuration in the policy.

If you remove a bridge or bonding interface, any node NICs in the cluster that were previously attached or subordinate to that bridge or bonding interface are placed in a down state and become unreachable. To avoid losing connectivity, configure the node NIC in the same policy so that it has a status of up and either DHCP or a static IP address.

Note

Deleting the node network policy that added an interface does not change the configuration of the policy on the node. Although a NodeNetworkConfigurationPolicy is an object in the cluster, it only represents the requested configuration.
Similarly, removing an interface does not delete the policy.

Procedure

  1. Update the NodeNetworkConfigurationPolicy manifest used to create the interface. The following example removes a Linux bridge and configures the eth1 NIC with DHCP to avoid losing connectivity: 

    apiVersion: nmstate.io/v1
kind: NodeNetworkConfigurationPolicy
metadata:
  name: <br1-eth1-policy> 1
spec:
  nodeSelector: 2
    node-role.kubernetes.io/worker: "" 3
  desiredState:
    interfaces:
    - name: br1
      type: linux-bridge
      state: absent 4
    - name: eth1 5
      type: ethernet 6
      state: up 7
      ipv4:
        dhcp: true 8
        enabled: true 9
    1
    Name of the policy.
    2
    Optional: If you do not include the nodeSelector parameter, the policy applies to all nodes in the cluster.
    3
    This example uses the node-role.kubernetes.io/worker: "" node selector to select all worker nodes in the cluster.
    4
    Changing the state to absent removes the interface.
    5
    The name of the interface that is to be unattached from the bridge interface.
    6
    The type of interface. This example creates an Ethernet networking interface.
    7
    The requested state for the interface.
    8
    Optional: If you do not use dhcp, you can either set a static IP or leave the interface without an IP address.
    9
    Enables ipv4 in this example.

  2. Update the policy on the node and remove the interface: 

    $ oc apply -f <br1-eth1-policy.yaml> 1
    1
    File name of the policy manifest.

24.1.5. Example policy configurations for different interfaces

Before you read the different example NodeNetworkConfigurationPolicy (NNCP) manifest configurations, consider the following factors when you apply a policy so that your cluster runs at its best performance conditions:

  • When you need to apply a policy to more than one node, create a NodeNetworkConfigurationPolicy manifest for each target node. The Kubernetes NMState Operator applies the policy to each node with an NNCP in an unspecified order. Scoping a policy with this approach reduces the length of time for policy application but risks a cluster-wide outage if an error is in the cluster’s configuration. To avoid this type of error, initially apply NNCP to some nodes, and after you confirm they are configured correctly, proceed with applying the policy to the remaining nodes.
  • When you need to apply a policy to many nodes but you only want to create a single NNCP for all target nodes, the Kubernetes NMState Operator applies the policy to each node in sequence. You can set the speed and coverage of policy application for target nodes with the maxUnavailable parameter in the cluster configuration. By setting a lower percentage value for the parameter, you can reduce the risk of a cluster-wide outage if the outage impacts the small percentage of nodes that are receiving the policy application.
  • Consider specifying all related network configurations in a single policy.
  • When a node restarts, the Kubernetes NMState Operator cannot control the order that it applies policies to nodes. The Kubernetes NMState Operator might apply interdependent policies in a sequence that results in a degraded network object.

24.1.5.1. Example: Linux bridge interface node network configuration policy

Create a Linux bridge interface on nodes in the cluster by applying a NodeNetworkConfigurationPolicy manifest to the cluster.

The following YAML file is an example of a manifest for a Linux bridge interface. It includes samples values that you must replace with your own information. 

apiVersion: nmstate.io/v1
kind: NodeNetworkConfigurationPolicy
metadata:
  name: br1-eth1-policy 1
spec:
  nodeSelector: 2
    kubernetes.io/hostname: <node01> 3
  desiredState:
    interfaces:
      - name: br1 4
        description: Linux bridge with eth1 as a port 5
        type: linux-bridge 6
        state: up 7
        ipv4:
          dhcp: true 8
          enabled: true 9
        bridge:
          options:
            stp:
              enabled: false 10
          port:
            - name: eth1 11
1
Name of the policy.
2
Optional: If you do not include the nodeSelector parameter, the policy applies to all nodes in the cluster.
3
This example uses a hostname node selector.
4
Name of the interface.
5
Optional: Human-readable description of the interface.
6
The type of interface. This example creates a bridge.
7
The requested state for the interface after creation.
8
Optional: If you do not use dhcp, you can either set a static IP or leave the interface without an IP address.
9
Enables ipv4 in this example.
10
Disables stp in this example.
11
The node NIC to which the bridge attaches.

24.1.5.2. Example: VLAN interface node network configuration policy

Create a VLAN interface on nodes in the cluster by applying a NodeNetworkConfigurationPolicy manifest to the cluster.

Note

Define all related configurations for the VLAN interface of a node in a single NodeNetworkConfigurationPolicy manifest. For example, define the VLAN interface for a node and the related routes for the VLAN interface in the same NodeNetworkConfigurationPolicy manifest.

When a node restarts, the Kubernetes NMState Operator cannot control the order in which policies are applied. Therefore, if you use separate policies for related network configurations, the Kubernetes NMState Operator might apply these policies in a sequence that results in a degraded network object.

The following YAML file is an example of a manifest for a VLAN interface. It includes samples values that you must replace with your own information. 

apiVersion: nmstate.io/v1
kind: NodeNetworkConfigurationPolicy
metadata:
  name: vlan-eth1-policy 1
spec:
  nodeSelector: 2
    kubernetes.io/hostname: <node01> 3
  desiredState:
    interfaces:
    - name: eth1.102 4
      description: VLAN using eth1 5
      type: vlan 6
      state: up 7
      vlan:
        base-iface: eth1 8
        id: 102 9
1
Name of the policy.
2
Optional: If you do not include the nodeSelector parameter, the policy applies to all nodes in the cluster.
3
This example uses a hostname node selector.
4
Name of the interface. When deploying on bare metal, only the <interface_name>.<vlan_number> VLAN format is supported.
5
Optional: Human-readable description of the interface.
6
The type of interface. This example creates a VLAN.
7
The requested state for the interface after creation.
8
The node NIC to which the VLAN is attached.
9
The VLAN tag.

24.1.5.3. Example: Node network configuration policy for virtual functions (Technology Preview)

Update host network settings for Single Root I/O Virtualization (SR-IOV) network virtual functions (VF) in an existing cluster by applying a NodeNetworkConfigurationPolicy manifest.

Important

Updating host network settings for SR-IOV network VFs 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.

You can apply a NodeNetworkConfigurationPolicy manifest to an existing cluster to complete the following tasks:

  • Configure QoS host network settings for VFs to optimize performance.
  • Add, remove, or update VFs for a network interface.
  • Manage VF bonding configurations.
Note

To update host network settings for SR-IOV VFs by using NMState on physical functions that are also managed through the SR-IOV Network Operator, you must set the externallyManaged parameter in the relevant SriovNetworkNodePolicy resource to true. For more information, see the Additional resources section.

The following YAML file is an example of a manifest that defines QoS policies for a VF. This file includes samples values that you must replace with your own information. 

apiVersion: nmstate.io/v1
kind: NodeNetworkConfigurationPolicy
metadata:
  name: qos 1
spec:
  nodeSelector: 2
    node-role.kubernetes.io/worker: "" 3
  desiredState:
    interfaces:
      - name: ens1f0 4
        description: Change QOS on VF0 5
        type: ethernet 6
        state: up 7
        ethernet:
         sr-iov:
           total-vfs: 3 8
           vfs:
           - id: 0 9
             max-tx-rate: 200 10
1
Name of the policy.
2
Optional: If you do not include the nodeSelector parameter, the policy applies to all nodes in the cluster.
3
This example applies to all nodes with the worker role.
4
Name of the physical function (PF) network interface.
5
Optional: Human-readable description of the interface.
6
The type of interface.
7
The requested state for the interface after configuration.
8
The total number of VFs.
9
Identifies the VF with an ID of 0.
10
Sets a maximum transmission rate, in Mbps, for the VF. This sample value sets a rate of 200 Mbps.

The following YAML file is an example of a manifest that creates a VLAN interface on top of a VF and adds it to a bonded network interface. It includes samples values that you must replace with your own information. 

apiVersion: nmstate.io/v1
kind: NodeNetworkConfigurationPolicy
metadata:
  name: addvf 1
spec:
  nodeSelector: 2
    node-role.kubernetes.io/worker: "" 3
  maxUnavailable: 3
  desiredState:
    interfaces:
      - name: ens1f0v1 4
        type: ethernet
        state: up
      - name: ens1f0v1.477 5
        type: vlan
        state: up
        vlan:
          base-iface: ens1f0v1 6
          id: 477
      - name: bond0 7
        description: Add vf 8
        type: bond 9
        state: up 10
        link-aggregation:
          mode: active-backup 11
          options:
            primary: ens1f1v0.477 12
          port: 13
            - ens1f1v0.477
            - ens1f0v0.477
            - ens1f0v1.477 14
1
Name of the policy.
2
Optional: If you do not include the nodeSelector parameter, the policy applies to all nodes in the cluster.
3
This example applies to all nodes with the worker role.
4
Name of the VF network interface.
5
Name of the VLAN network interface.
6
The VF network interface to which the VLAN interface is attached.
7
Name of the bonding network interface.
8
Optional: Human-readable description of the interface.
9
The type of interface.
10
The requested state for the interface after configuration.
11
The bonding policy for the bond.
12
The primary attached bonding port.
13
The ports for the bonded network interface.
14
In this example, this VLAN network interface is added as an additional interface to the bonded network interface.

Additional resources

24.1.5.4. Example: Bond interface node network configuration policy

Create a bond interface on nodes in the cluster by applying a NodeNetworkConfigurationPolicy manifest to the cluster.

Note

OpenShift Container Platform only supports the following bond modes:

  • mode=1 active-backup
  • mode=2 balance-xor
  • mode=4 802.3ad

Other bond modes are not supported.

The following YAML file is an example of a manifest for a bond interface. It includes samples values that you must replace with your own information. 

apiVersion: nmstate.io/v1
kind: NodeNetworkConfigurationPolicy
metadata:
  name: bond0-eth1-eth2-policy 1
spec:
  nodeSelector: 2
    kubernetes.io/hostname: <node01> 3
  desiredState:
    interfaces:
    - name: bond0 4
      description: Bond with ports eth1 and eth2 5
      type: bond 6
      state: up 7
      ipv4:
        dhcp: true 8
        enabled: true 9
      link-aggregation:
        mode: active-backup 10
        options:
          miimon: '140' 11
        port: 12
        - eth1
        - eth2
      mtu: 1450 13
1
Name of the policy.
2
Optional: If you do not include the nodeSelector parameter, the policy applies to all nodes in the cluster.
3
This example uses a hostname node selector.
4
Name of the interface.
5
Optional: Human-readable description of the interface.
6
The type of interface. This example creates a bond.
7
The requested state for the interface after creation.
8
Optional: If you do not use dhcp, you can either set a static IP or leave the interface without an IP address.
9
Enables ipv4 in this example.
10
The driver mode for the bond. This example uses an active backup mode.
11
Optional: This example uses miimon to inspect the bond link every 140ms.
12
The subordinate node NICs in the bond.
13
Optional: The maximum transmission unit (MTU) for the bond. If not specified, this value is set to 1500 by default.

24.1.5.5. Example: Ethernet interface node network configuration policy

Configure an Ethernet interface on nodes in the cluster by applying a NodeNetworkConfigurationPolicy manifest to the cluster.

The following YAML file is an example of a manifest for an Ethernet interface. It includes sample values that you must replace with your own information. 

apiVersion: nmstate.io/v1
kind: NodeNetworkConfigurationPolicy
metadata:
  name: eth1-policy 1
spec:
  nodeSelector: 2
    kubernetes.io/hostname: <node01> 3
  desiredState:
    interfaces:
    - name: eth1 4
      description: Configuring eth1 on node01 5
      type: ethernet 6
      state: up 7
      ipv4:
        dhcp: true 8
        enabled: true 9
1
Name of the policy.
2
Optional: If you do not include the nodeSelector parameter, the policy applies to all nodes in the cluster.
3
This example uses a hostname node selector.
4
Name of the interface.
5
Optional: Human-readable description of the interface.
6
The type of interface. This example creates an Ethernet networking interface.
7
The requested state for the interface after creation.
8
Optional: If you do not use dhcp, you can either set a static IP or leave the interface without an IP address.
9
Enables ipv4 in this example.

24.1.5.6. Example: Multiple interfaces in the same node network configuration policy

You can create multiple interfaces in the same node network configuration policy. These interfaces can reference each other, allowing you to build and deploy a network configuration by using a single policy manifest.

The following example YAML file creates a bond that is named bond10 across two NICs and VLAN that is named bond10.103 that connects to the bond. 

apiVersion: nmstate.io/v1
kind: NodeNetworkConfigurationPolicy
metadata:
  name: bond-vlan 1
spec:
  nodeSelector: 2
    kubernetes.io/hostname: <node01> 3
  desiredState:
    interfaces:
    - name: bond10 4
      description: Bonding eth2 and eth3 5
      type: bond 6
      state: up 7
      link-aggregation:
        mode: balance-xor 8
        options:
          miimon: '140' 9
        port: 10
        - eth2
        - eth3
    - name: bond10.103 11
      description: vlan using bond10 12
      type: vlan 13
      state: up 14
      vlan:
         base-iface: bond10 15
         id: 103 16
      ipv4:
        dhcp: true 17
        enabled: true 18
1
Name of the policy.
2
Optional: If you do not include the nodeSelector parameter, the policy applies to all nodes in the cluster.
3
This example uses hostname node selector.
4 11
Name of the interface.
5 12
Optional: Human-readable description of the interface.
6 13
The type of interface.
7 14
The requested state for the interface after creation.
8
The driver mode for the bond.
9
Optional: This example uses miimon to inspect the bond link every 140ms.
10
The subordinate node NICs in the bond.
15
The node NIC to which the VLAN is attached.
16
The VLAN tag.
17
Optional: If you do not use dhcp, you can either set a static IP or leave the interface without an IP address.
18
Enables ipv4 in this example.

24.1.5.7. Example: Network interface with a VRF instance node network configuration policy

Associate a Virtual Routing and Forwarding (VRF) instance with a network interface by applying a NodeNetworkConfigurationPolicy custom resource (CR).

Important

Associating a VRF instance with a network interface 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.

By associating a VRF instance with a network interface, you can support traffic isolation, independent routing decisions, and the logical separation of network resources.

In a bare-metal environment, you can announce load balancer services through interfaces belonging to a VRF instance by using MetalLB. For more information, see the Additional resources section.

The following YAML file is an example of associating a VRF instance to a network interface. It includes samples values that you must replace with your own information. 

apiVersion: nmstate.io/v1
kind: NodeNetworkConfigurationPolicy
metadata:
  name: vrfpolicy 1
spec:
  nodeSelector:
    vrf: "true" 2
  maxUnavailable: 3
  desiredState:
    interfaces:
      - name: ens4vrf 3
        type: vrf 4
        state: up
        vrf:
          port:
            - ens4 5
          route-table-id: 2 6
1
The name of the policy.
2
This example applies the policy to all nodes with the label vrf:true.
3
The name of the interface.
4
The type of interface. This example creates a VRF instance.
5
The node interface to which the VRF attaches.
6
The name of the route table ID for the VRF.

Additional resources

24.1.6. Capturing the static IP of a NIC attached to a bridge

Important

Capturing the static IP of a NIC 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.

24.1.6.1. Example: Linux bridge interface node network configuration policy to inherit static IP address from the NIC attached to the bridge

Create a Linux bridge interface on nodes in the cluster and transfer the static IP configuration of the NIC to the bridge by applying a single NodeNetworkConfigurationPolicy manifest to the cluster.

The following YAML file is an example of a manifest for a Linux bridge interface. It includes sample values that you must replace with your own information. 

apiVersion: nmstate.io/v1
kind: NodeNetworkConfigurationPolicy
metadata:
  name: br1-eth1-copy-ipv4-policy 1
spec:
  nodeSelector: 2
    node-role.kubernetes.io/worker: ""
  capture:
    eth1-nic: interfaces.name=="eth1" 3
    eth1-routes: routes.running.next-hop-interface=="eth1"
    br1-routes: capture.eth1-routes | routes.running.next-hop-interface := "br1"
  desiredState:
    interfaces:
      - name: br1
        description: Linux bridge with eth1 as a port
        type: linux-bridge 4
        state: up
        ipv4: "{{ capture.eth1-nic.interfaces.0.ipv4 }}" 5
        bridge:
          options:
            stp:
              enabled: false
          port:
            - name: eth1 6
     routes:
        config: "{{ capture.br1-routes.routes.running }}"
1
The name of the policy.
2
Optional: If you do not include the nodeSelector parameter, the policy applies to all nodes in the cluster. This example uses the node-role.kubernetes.io/worker: "" node selector to select all worker nodes in the cluster.
3
The reference to the node NIC to which the bridge attaches.
4
The type of interface. This example creates a bridge.
5
The IP address of the bridge interface. This value matches the IP address of the NIC which is referenced by the spec.capture.eth1-nic entry.
6
The node NIC to which the bridge attaches.

Additional resources

24.1.7. Examples: IP management

The following example configuration snippets show different methods of IP management.

These examples use the ethernet interface type to simplify the example while showing the related context in the policy configuration. These IP management examples can be used with the other interface types.

24.1.7.1. Static

The following snippet statically configures an IP address on the Ethernet interface: 

# ...
    interfaces:
    - name: eth1
      description: static IP on eth1
      type: ethernet
      state: up
      ipv4:
        dhcp: false
        address:
        - ip: 192.168.122.250 1
          prefix-length: 24
        enabled: true
# ...
1
Replace this value with the static IP address for the interface.

24.1.7.2. No IP address

The following snippet ensures that the interface has no IP address: 

# ...
    interfaces:
    - name: eth1
      description: No IP on eth1
      type: ethernet
      state: up
      ipv4:
        enabled: false
# ...

24.1.7.3. Dynamic host configuration

The following snippet configures an Ethernet interface that uses a dynamic IP address, gateway address, and DNS: 

# ...
    interfaces:
    - name: eth1
      description: DHCP on eth1
      type: ethernet
      state: up
      ipv4:
        dhcp: true
        enabled: true
# ...

The following snippet configures an Ethernet interface that uses a dynamic IP address but does not use a dynamic gateway address or DNS: 

# ...
    interfaces:
    - name: eth1
      description: DHCP without gateway or DNS on eth1
      type: ethernet
      state: up
      ipv4:
        dhcp: true
        auto-gateway: false
        auto-dns: false
        enabled: true
# ...

24.1.7.4. DNS

By default, the nmstate API stores DNS values globally as against storing them in a network interface. For certain situations, you must configure a network interface to store DNS values.

Tip

Setting a DNS configuration is comparable to modifying the /etc/resolv.conf file.

To define a DNS configuration for a network interface, you must initially specify the dns-resolver section in the network interface’s YAML configuration file.

Important

You cannot use br-ex bridge, an OVNKubernetes-managed Open vSwitch bridge, as the interface when configuring DNS resolvers unless you manually configured a customized br-ex bridge.

For more information, see "Creating a manifest object that includes a customized br-ex bridge" in the Deploying installer-provisioned clusters on bare metal document or the Installing a user-provisioned cluster on bare metal document.

The following example shows a default situation that stores DNS values globally:

  • Configure a static DNS without a network interface. Note that when updating the /etc/resolv.conf file on a host node, you do not need to specify an interface, IPv4 or IPv6, in the NodeNetworkConfigurationPolicy (NNCP) manifest.

    Example of a DNS configuration for a network interface that globally stores DNS values

    apiVersion: nmstate.io/v1
kind: NodeNetworkConfigurationPolicy
metadata:
 name: worker-0-dns-testing
spec:
  nodeSelector:
    kubernetes.io/hostname: <target_node>
  desiredState:
    dns-resolver:
      config:
        search:
        - example.com
        - example.org
        server:
        - 2001:db8:f::1
        - 192.0.2.251
# ...

The following examples show situations that require configuring a network interface to store DNS values:

  • If you want to rank a static DNS name server over a dynamic DNS name server, define the interface that runs either the Dynamic Host Configuration Protocol (DHCP) or the IPv6 Autoconfiguration (autoconf) mechanism in the network interface YAML configuration file.

    Example configuration that adds 192.0.2.1 to DNS name servers retrieved from the DHCPv4 network protocol

    # ...
dns-resolver:
  config:
    server:
    - 192.0.2.1
interfaces:
  - name: eth1
    type: ethernet
    state: up
    ipv4:
      enabled: true
      dhcp: true
      auto-dns: true
# ...

  • If you need to configure a network interface to store DNS values instead of adopting the default method, which uses the nmstate API to store DNS values globally, you can set static DNS values and static IP addresses in the network interface YAML file.

    Important

    Storing DNS values at the network interface level might cause name resolution issues after you attach the interface to network components, such as an Open vSwitch (OVS) bridge, a Linux bridge, or a bond.

    Example configuration that stores DNS values at the interface level

    # ...
dns-resolver:
  config:
    search:
    - example.com
    - example.org
    server:
    - 2001:db8:1::d1
    - 2001:db8:1::d2
    - 192.0.2.1
interfaces:
  - name: eth1
    type: ethernet
    state: up
    ipv4:
      address:
      - ip: 192.0.2.251
        prefix-length: 24
      dhcp: false
      enabled: true
    ipv6:
      address:
      - ip: 2001:db8:1::1
        prefix-length: 64
      dhcp: false
      enabled: true
      autoconf: false
# ...

  • If you want to set static DNS search domains and dynamic DNS name servers for your network interface, define the dynamic interface that runs either the Dynamic Host Configuration Protocol (DHCP) or the IPv6 Autoconfiguration (autoconf) mechanism in the network interface YAML configuration file.

    Example configuration that sets example.com and example.org static DNS search domains along with dynamic DNS name server settings

    # ...
dns-resolver:
  config:
    search:
    - example.com
    - example.org
    server: []
interfaces:
  - name: eth1
    type: ethernet
    state: up
    ipv4:
      enabled: true
      dhcp: true
      auto-dns: true
    ipv6:
      enabled: true
      dhcp: true
      autoconf: true
      auto-dns: true
# ...

24.1.7.5. Static routing

The following snippet configures a static route and a static IP on interface eth1. 

dns-resolver:
  config:
# ...
interfaces:
  - name: eth1
    description: Static routing on eth1
    type: ethernet
    state: up
    ipv4:
      dhcp: false
      enabled: true
      address:
      - ip: 192.0.2.251 1
        prefix-length: 24
routes:
  config:
  - destination: 198.51.100.0/24
    metric: 150
    next-hop-address: 192.0.2.1 2
    next-hop-interface: eth1
    table-id: 254
# ...
1
The static IP address for the Ethernet interface.
2
Next hop address for the node traffic. This must be in the same subnet as the IP address set for the Ethernet interface.

Additional resources

24.2. Troubleshooting node network configuration

If the node network configuration encounters an issue, the policy is automatically rolled back and the enactments report failure. This includes issues such as:

  • The configuration fails to be applied on the host.
  • The host loses connection to the default gateway.
  • The host loses connection to the API server.

24.2.1. Troubleshooting an incorrect node network configuration policy configuration

You can apply changes to the node network configuration across your entire cluster by applying a node network configuration policy.

If you applied an incorrect configuration, you can use the following example to troubleshoot and correct the failed node network policy. The example attempts to apply a Linux bridge policy to a cluster that has three control plane nodes and three compute nodes. The policy is not applied because the policy references the wrong interface.

To find an error, you need to investigate the available NMState resources. You can then update the policy with the correct configuration.

Prerequisites

  • You ensured that an ens01 interface does not exist on your Linux system.

Procedure

  1. Create a policy on your cluster. The following example creates a simple bridge, br1 that has ens01 as its member: 

    apiVersion: nmstate.io/v1
kind: NodeNetworkConfigurationPolicy
metadata:
  name: ens01-bridge-testfail
spec:
  desiredState:
    interfaces:
      - name: br1
        description: Linux bridge with the wrong port
        type: linux-bridge
        state: up
        ipv4:
          dhcp: true
          enabled: true
        bridge:
          options:
            stp:
              enabled: false
          port:
            - name: ens01
# ...

  2. Apply the policy to your network interface: 

    $ oc apply -f ens01-bridge-testfail.yaml

    Example output

    nodenetworkconfigurationpolicy.nmstate.io/ens01-bridge-testfail created

  3. Verify the status of the policy by running the following command: 

    $ oc get nncp

    The output shows that the policy failed:

    Example output

    NAME                    STATUS
ens01-bridge-testfail   FailedToConfigure

    The policy status alone does not indicate if it failed on all nodes or a subset of nodes.

  4. List the node network configuration enactments to see if the policy was successful on any of the nodes. If the policy failed for only a subset of nodes, the output suggests that the problem is with a specific node configuration. If the policy failed on all nodes, the output suggests that the problem is with the policy. 

    $ oc get nnce

    The output shows that the policy failed on all nodes:

    Example output

    NAME                                         STATUS
control-plane-1.ens01-bridge-testfail        FailedToConfigure
control-plane-2.ens01-bridge-testfail        FailedToConfigure
control-plane-3.ens01-bridge-testfail        FailedToConfigure
compute-1.ens01-bridge-testfail              FailedToConfigure
compute-2.ens01-bridge-testfail              FailedToConfigure
compute-3.ens01-bridge-testfail              FailedToConfigure

  5. View one of the failed enactments. The following command uses the output tool jsonpath to filter the output: 

    $ oc get nnce compute-1.ens01-bridge-testfail -o jsonpath='{.status.conditions[?(@.type=="Failing")].message}'

    Example output

    [2024-10-10T08:40:46Z INFO  nmstatectl] Nmstate version: 2.2.37
NmstateError: InvalidArgument: Controller interface br1 is holding unknown port ens01

    The previous example shows the output from an InvalidArgument error that indicates that the ens01 is an unknown port. For this example, you might need to change the port configuration in the policy configuration file.

  6. To ensure that the policy is configured properly, view the network configuration for one or all of the nodes by requesting the NodeNetworkState object. The following command returns the network configuration for the control-plane-1 node: 

    $ oc get nns control-plane-1 -o yaml

    The output shows that the interface name on the nodes is ens1 but the failed policy incorrectly uses ens01:

    Example output

       - ipv4:
# ...
      name: ens1
      state: up
      type: ethernet

  7. Correct the error by editing the existing policy: 

    $ oc edit nncp ens01-bridge-testfail
    # ...
          port:
            - name: ens1

    Save the policy to apply the correction.

  8. Check the status of the policy to ensure it updated successfully: 

    $ oc get nncp

    Example output

    NAME                    STATUS
ens01-bridge-testfail   SuccessfullyConfigured

    The updated policy is successfully configured on all nodes in the cluster.

24.2.2. Troubleshooting DNS connectivity issues in a disconnected environment

If you experience DNS connectivity issues when configuring nmstate in a disconnected environment, you can configure the DNS server to resolve the list of name servers for the domain root-servers.net.

Important

Ensure that the DNS server includes a name server (NS) entry for the root-servers.net zone. The DNS server does not need to forward a query to an upstream resolver, but the server must return a correct answer for the NS query.

24.2.2.1. Configuring the bind9 DNS named server

For a cluster configured to query a bind9 DNS server, you can add the root-servers.net zone to a configuration file that contains at least one NS record. For example you can use the /var/named/named.localhost as a zone file that already matches this criteria.

Procedure

  1. Add the root-servers.net zone at the end of the /etc/named.conf configuration file by running the following command: 

    $ cat >> /etc/named.conf <<EOF
zone "root-servers.net" IN {
    	type master;
    	file "named.localhost";
};
EOF

  2. Restart the named service by running the following command: 

    $ systemctl restart named

  3. Confirm that the root-servers.net zone is present by running the following command: 

    $ journalctl -u named|grep root-servers.net

    Example output

    Jul 03 15:16:26 rhel-8-10 bash[xxxx]: zone root-servers.net/IN: loaded serial 0
Jul 03 15:16:26 rhel-8-10 named[xxxx]: zone root-servers.net/IN: loaded serial 0

  4. Verify that the DNS server can resolve the NS record for the root-servers.net domain by running the following command: 

    $ host -t NS root-servers.net. 127.0.0.1

    Example output

    Using domain server:
Name: 127.0.0.1
Address: 127.0.0.53
Aliases:
root-servers.net name server root-servers.net.

24.2.2.2. Configuring the dnsmasq DNS server

If you are using dnsmasq as the DNS server, you can delegate resolution of the root-servers.net domain to another DNS server, for example, by creating a new configuration file that resolves root-servers.net using a DNS server that you specify.

  1. Create a configuration file that delegates the domain root-servers.net to another DNS server by running the following command: 

    $ echo 'server=/root-servers.net/<DNS_server_IP>'> /etc/dnsmasq.d/delegate-root-servers.net.conf

  2. Restart the dnsmasq service by running the following command: 

    $ systemctl restart dnsmasq

  3. Confirm that the root-servers.net domain is delegated to another DNS server by running the following command: 

    $ journalctl -u dnsmasq|grep root-servers.net

    Example output

    Jul 03 15:31:25 rhel-8-10 dnsmasq[1342]: using nameserver 192.168.1.1#53 for domain root-servers.net

  4. Verify that the DNS server can resolve the NS record for the root-servers.net domain by running the following command: 

    $ host -t NS root-servers.net. 127.0.0.1

    Example output

    Using domain server:
Name: 127.0.0.1
Address: 127.0.0.1#53
Aliases:
root-servers.net name server root-servers.net.

Red Hat logoGithubRedditYoutubeTwitter

Learn

Try, buy, & sell

Communities

About Red Hat Documentation

We help Red Hat users innovate and achieve their goals with our products and services with content they can trust.

Making open source more inclusive

Red Hat is committed to replacing problematic language in our code, documentation, and web properties. For more details, see the Red Hat Blog.

About Red Hat

We deliver hardened solutions that make it easier for enterprises to work across platforms and environments, from the core datacenter to the network edge.

© 2024 Red Hat, Inc.