nerdctl compose support for interface_name and translation to CNI_IFNAME

[tariromukute]

Hi everyone,

I wanted to ask if nerdctl compose currently supports the interface_name property when defining networks for a service.

I am trying to migrate some workflows to nerdctl, and my use case requires specific naming for network interfaces inside the container (e.g., mapping a specific network to web0 instead of eth0 or eth1).

In the Compose Specification, interface_name is defined under the network configuration for a service. When using CNI, this typically translates to passing the CNI_IFNAME argument to the plugin.

I inspected the nerdctl source code briefly and couldn't find references to interface_name or CNI_IFNAME being propagated from the compose file, so I assume this might not be implemented yet.

Sample compose.yaml:

version: '3.8'
services:
  web:
    image: nginx:alpine
    networks:
      ovsnet:
        ipv4_address: 10.50.0.100
        interface_name: web0  # <--- This is the field I need

Expected Behavior:
When nerdctl compose up starts this container, the CNI plugin for the ovsnet network should receive CNI_IFNAME=web0.

Is this something that is on the roadmap, or would you be open to a feature request/PR to add this support?

Thanks!

[AkihiroSuda]

Is this something that is on the roadmap, or would you be open to a feature request/PR to add this support?

Yes, PR is welcome