Make groups work as they were designed to

[hellt]

Containerlab topology definition file had a notion of a group forever. But we never implemented them in the way they were envisioned to be used.

A group should allow a user to define a common set of node-level parameters that a certain node can then inherit via the group reference.

For example, the below topology defines a group leafs and adds some node-specific parameters to it. Then a node in the topology references this group to adopt the specified parameters:

name: group-demo
topology:
  groups:
    leafs:
      labels:
        someLabel: someValue
      type: ixrd3l

  nodes:
    node1:
      group: leafs

    node2:

node1 will inherit labels and type as defined in a group, whereas node2 will not.