NetworkInterface

A NetworkInterface resource in Ironcore represents a connection point between a virtual machine(VM) and a virtual network. It encapsulates the configuration and life cycle management of the virtual network interface, ensuring seamless connectivity for VMs.

The MachineEphemeralNetworkInterfaceReconciler is responsible for managing the lifecycle of ephemeral network interfaces associated with machines. Its primary function is to ensure that the actual state of these network interfaces aligns with the desired state specified in each machine's configuration.

Example NetworkPolicy Resource

An example of how to define a NetworkInterface resource in Ironcore

apiVersion: networking.ironcore.dev/v1alpha1
kind: NetworkInterface
metadata:
  name: networkinterface-sample
spec:
  networkRef:
    name: network-sample
  ipFamilies:
    - IPv4
  ips:
    - value: 10.0.0.1 # internal IP
  virtualIP:
    virtualIPRef:
      name: virtualip-sample

Note: For a detailed end-to-end example to understand the ephemeral and non-ephemeral NetworkInterface resource, please refer E2E Examples

Key Fields

• networkRef(string): NetworkRef is the Network this NetworkInterface is connected to

• ipFamilies(list): IPFamilies defines the list of IPFamilies this NetworkInterface supports. Supported values for IPFamily are IPv4 and IPv6.

• ips(list): IPs are the list of provided internal IPs which should be assigned to this NetworkInterface

• virtualIP: VirtualIP specifies the public ip that should be assigned to this NetworkInterface.

Reconciliation Process:

• Fetch Machine Resource: Retrieve the specified Machine resource from the reconciliation request. If the Machine is marked for deletion (indicated by a non-zero DeletionTimestamp), exit the process without further action.

• Generate Desired Ephemeral Network Interfaces: Analyze the Machine's specification to identify the desired ephemeral NetworkInterface resources. Construct a map detailing these desired NetworkInterfaces, including their configurations and expected states.

• Fetch Existing NetworkInterfaces: List all existing NetworkInterface resources within the same namespace as the Machine.

• Compare and Reconcile:

  • For each existing Network Interface: Determine if it is managed by the current Machine and whether it matches the desired state.
  • If unmanaged but should be managed, avoid adopting it to prevent conflicts.
  • For each desired Network Interface not present: Create the missing NetworkInterface and establish the Machine as its controller.

• Handle Errors: Collect any errors encountered during the reconciliation of individual NetworkInterfaces. Log these errors and schedule retries as necessary to ensure eventual consistency.

• Update Status: After reconciling all NetworkInterfaces, log the successful reconciliation and update the NetworkInterface status with the corresponding values for ips, state, and virtualIP, as shown below.

status:
  ips:
  - 10.0.0.1
  lastStateTransitionTime: "2025-01-13T11:39:17Z"
  state: Available
  virtualIP: 172.89.244.23

The state is updated as one of the following lifecycle states based on the reconciliation result - Pending - Available - Error