Option to name network interface inside container same as the respective podman network interface name or its parent by default

[vikas-goel]

Docker allows to customer network interface name inside containers using com.docker.network.container_iface_prefix option. Docker Compose too supports it.

How can same be done with Podman when used with Docker Compose?

Will be good to have containers.conf option, say interface_name = network|parent to make that default.

[Luap99]

We do not support any docker specific option via the compat api yet. It should be possible to map some of those to the podman options.
The network create backend does support setting a specific interface name but it does not support a prefix so I am not sure how we should map this.

[vikas-goel]

The network create backend does support setting a specific interface name

What is the command to achieve this? Is it specific to a particular driver or generic?

[Luap99]

You can use podman run --network mynet:interface_name=eth0 ... So you have to set the specific name not a prefix. So it is not exactly the same as docker.

[mheon]

I wonder if this is something that would be appropriate for containers.conf

[vikas-goel]

You can use podman run --network mynet:interface_name=eth0 ... So you have to set the specific name not a prefix. So it is not exactly the same as docker.

This podman option works better for me. Just that Docker Compose fails to recognize it. As @mheon suggested, it will be great if we can make it the default behavior by means of containers.conf.

[vikas-goel]

Just to be clear on the ask:
When set a property in containers.conf, say interface_name = “network”, the network interface name inside the container should be same as the respective network name used with --network option.

[vikas-goel]

Hi @Luap99 ,
Can this change be available in 4.0?

[Luap99]

I don't think so. This is definitely more complex to implement.

[rhatdan]

We are not adding features to podman 4.0 at this point, It should release later this week.
This would show up no earlier then 4.1.

[Luap99]

The problem with interface_name = "network" is that this will fail if the name contains invalid characters or is longer than 15 chars since the kernel has this limitation for interface names.

[vikas-goel]

For my use case, either of parent and network will work as the network name is same as parent. If “parent” makes it easy, that’s fine too.

[Luap99]

What does "parent" means, the interface name on host?