Updated on 2024-01-26 GMT+08:00

NetworkAttachmentDefinition

Scenario

In a CCE Turbo cluster, you can set the subnet and security group for a container by namespace using NetworkAttachmentDefinition, a CRD resource in the cluster. After NetworkAttachmentDefinition is configured for a namespace, pods in the namespace support the following functions:
  • Binding a container with a subnet: The pod IP address is restricted in a specific CIDR block. Different namespaces can be isolated from each other.
  • Binding a container with a security group: Security group rules can be set for pods in the same namespace to customize access policies.

Constraints

  • NetworkAttachmentDefinition is available only in CCE Turbo clusters of v1.23.8-r0, v1.25.3-r0, and later.
  • Only default-network supports ENI preheating. User-defined container subnets do not support ENI preheating. If ENI preheating is not enabled, workload instance creation slows down. Therefore, this function is not applicable to high-performance pod creation scenarios.
  • To delete a NetworkAttachmentDefinition, delete pods (with the annotation named cni.yangtse.io/network-status) created using the configuration in the corresponding namespace first. For details, see Deleting a Network Configuration.

Using the CCE Console

  1. Log in to the CCE console.
  2. Click the cluster name to access the cluster console. Choose System Configuration in the navigation pane and click the Network Configuration tab.

    Each cluster has a default-network for namespaces with no container subnets. The default container subnet displayed in the network information on the networking configuration area is the container subnet in default-network. The default-network cannot be deleted.

  3. Click Create Network Configurations in the upper right corner. Configure the basic parameters in the displayed dialog box.

    • Name: Enter a name that contains a maximum of 253 characters. Do not use default-network, default, mgnt0, and mgnt1.
    • Namespace: Select a namespace. The namespaces of different configurations must be unique. If no namespace is available, click Create Namespace to create one.
    • Pod Subnet: Select a subnet. If no subnet is available, click Create Subnet to create a subnet. After the subnet is created, click the refresh button. A maximum of 20 subnets can be selected.
    • Associate Security Group: The default value is the container ENI security group. You can also click Create Security Group to create one. After the security group is created, click the refresh button. A maximum of five security groups can be selected.

  4. Click Create. After the creation is complete, you will be redirected to the network configuration list. You can see that the newly added subnet is in the list.

Using kubectl

This section describes how to create an NAD using kubectl.

  1. Use kubectl to connect to the cluster. For details, see Connecting to a Cluster Using kubectl.
  2. Modify the networkattachment-test.yaml file.

    vi networkattachment-test.yaml

    apiVersion: k8s.cni.cncf.io/v1
    kind: NetworkAttachmentDefinition
    metadata:
      annotations:
        yangtse.io/project-id: 05e38**
      name: example
      namespace: kube-system
    spec:
      config: 
      '{
        "type":"eni-neutron",
        "args":{
          "securityGroups":"41891**",
          "subnets":[
            {
              "subnetID":"27d95**"
            }
          ]
        },
        "selector":{
          "namespaceSelector":{
            "matchLabels":{
              "kubernetes.io/metadata.name":"default"
            }
          }
        }
      }'
    Table 1 Key parameters

    Parameter

    Mandatory

    Type

    Description

    apiVersion

    Yes

    String

    API version. The value is fixed at k8s.cni.cncf.io/v1.

    kind

    Yes

    String

    Type of the object to be created. The value is fixed at NetworkAttachmentDefinition.

    yangtse.io/project-id

    Yes

    String

    Project ID.

    name

    Yes

    String

    Configuration item name.

    namespace

    Yes

    String

    Namespace of the configuration resource. The value is fixed to kube-system.

    config

    Yes

    Table 2 object

    Configuration content, which is a string in JSON format.

    Table 2 config parameters

    Parameter

    Mandatory

    Type

    Description

    type

    Yes

    String

    The value is fixed at eni-neutron.

    args

    No

    Table 3

    object

    Configuration parameters.

    selector

    No

    Table 4 object

    Namespace on which the configuration takes effect.

    Table 3 args parameters

    Parameter

    Mandatory

    Type

    Description

    securityGroups

    No

    String

    Security group ID. If no security group is planned, select the same security group as that in default-network.

    Obtaining the value:

    Log in to the VPC console. In the navigation pane, choose Access Control > Security Groups. Click the target security group name and copy the ID on the Summary tab page.

    subnets

    Yes

    Array of subnetID Objects

    List of container subnet IDs. At least one subnet ID must be entered. The format is as follows:

    [{"subnetID":"27d95**"},{"subnetID":"827bb**"},{"subnetID":"bdd6b**"}]

    Subnet ID not used by the cluster in the same VPC.

    Obtaining the value:

    Log in to the VPC console. In the navigation pane, choose Virtual Private Cloud > Subnets. Click the target subnet name and copy the Subnet ID on the Summary tab page.

    Table 4 selector parameters

    Parameter

    Mandatory

    Type

    Description

    namespaceSelector

    No

    matchLabels Object

    A Kubernetes standard selector. Enter the namespace label in the following format:

    "matchLabels":{
              "kubernetes.io/metadata.name":"default"
            }

    The namespaces of different configurations cannot overlap.

  3. Create a NetworkAttachmentDefinition.

    kubectl create -f networkattachment-test.yaml

    If information similar to the following is displayed, the NetworkAttachmentDefinition has been created.

    networkattachmentdefinition.k8s.cni.cncf.io/example created

Deleting a Network Configuration

You can delete the new network configuration or view its YAML file.

Before deleting a network configuration, delete the container corresponding to the configuration. Otherwise, the deletion fails.

  1. Run the following command to filter the pod that uses the configuration in the cluster (example is an example configuration name and you should replace it):
    kubectl get po -A -o=jsonpath="{.items[?(@.metadata.annotations.cni\.yangtse\.io/network-status=='[{\"name\":\"example\"}]')]['metadata.namespace', 'metadata.name']}"

    The command output contains the pod name and namespace associated with the configuration.

  2. Delete the owner of the pod. The owner may be a Deployment, StatefulSet, DaemonSet, or Job.