Feature Request: declare static IP for macvlan endpoints

[pdumais]

When using "network-mode: none" on a node, and then creating an explicit link for the management interface, it would be nice to have a way to specify a static IP since "mgmt-ipv4" has not effect anymore.

For example:

name: test1 
topology:
    linux:
      image: centos
  nodes:
    linux:
      kind: linux
      network-mode: none
  links:
      - type: macvlan
        endpoint:
            node: linux
            interface: eth0
            mac: 6C:62:86:00:00:02
        host-interface: eth1
        mode: bridge

in this case, since the container usually doesn't start a dhcp-client, it wouldn't receive an IP.
So the container needs to be modified to either assign itself an IP from its entrypoint, or run dhclient. In each case, it means that the entrypoint of the container needs modification.
It would be helpful if an IP, defined in the extended link definition, could be assigned to the interface immediately after its creation by containerlab, the same way docker would do it. This would allow us to retain the functionality of "mgmt-ipv4" while using a macvlan or other type of link.

[steiler]

what you can do Patrick is to use the
exec: flag and set the ip that way.

https://containerlab.dev/manual/nodes/#exec

If you simply do an ip address add xzy dev eth0 you're done for linux nodes.
For the other node types, the supported NOS types you might want to add it to the startup-config.

[pdumais]

Ok, that's a good workaround. It would be nice if it would get done automatically, the same way that docker does it though.

No worries if you wanna close this.

[hellt]

docker doesn't do anything like that, since here we are talking about links added to the container besides eth0.

This is a very nuanced scenario and for now I don't want to dive into it for a single use case. Will move this FR to Ideas.

[pdumais]

Sounds good.