Group enhancement

[asadarafat]

The current group implementation, as documented [here](https://containerlab.dev/manual/nodes/#group), only supports using strings for topology generation.

It would be beneficial to enhance this functionality by introducing a level metadata attribute for groups, defined globally.

For example:

topology:
  defaults:
    labels:
      groups:
        - name: "Data Center Spine"
          level: 1
        - name: "Data Center Leaf"
          level: 2

With this enhancement, the level metadata could be utilized to create layouts where parent nodes are arranged radially, hierarchically or what ever layout algorithm based on their level.

[FloSch62]

I think most of tools available via the graph command using the naming graph-level
labels:
graph-level: 1
graph-icon: host

Having labels available via a group could slim down some .clab.ymls

[hellt]

yep, the right way to do that is via labels, not groups. Groups were once misued for it, but it was a wrong choice

[asadarafat]

yep, the right way to do that is via labels, not groups. Groups were once misued for it, but it was a wrong choice

So, the topology with labes should be like this?

name: demo-ci

topology:  
  nodes:
    Spine-01:
      kind: srl
      image: ghcr.io/nokia/srlinux
      labels:
        topoViewer-role: spine
        topoViewer-group: "Data Center Spine"
        topoViewer-groupLevel: 1

    Spine-02:
      kind: srl
      image: ghcr.io/nokia/srlinux
      labels:
        topoViewer-role: spine
        topoViewer-group: "Data Center Spine"
        topoViewer-groupLevel: 1

    Leaf-01:
      kind: srl
      image: ghcr.io/nokia/srlinux
      labels:
        topoViewer-role: spine
        topoViewer-group: "Data Center Leaf"
        topoViewer-groupLevel: 2    

    Leaf-02:
      kind: srl
      image: ghcr.io/nokia/srlinux
      labels:
        topoViewer-role: spine
        topoViewer-group: "Data Center Leaf"
        topoViewer-groupLevel: 2

[FloSch62]

Yes this something you can already do today, but as said, just use the same labels as the other graph tools ( graph-level, graph-icon ) to keep it compatible. I think the topoViewer, does not need its own labels ;)

For example https://github.com/netreplica/nrx is using the same labels as my clab-io-draw

[asadarafat]

Got it...

side question.. to make the yaml definition shorter, any plan to support yaml Anchors?

name: demo-ci

globals:
  groups:
    spine: &spineGroup
      group: "Data Center Spine"
      graph-level: 1
    leaf: &leafGroup
      topoViewer-group: "Data Center Leaf"
      level: 2

topology:  
  nodes:
    Spine-01:
      kind: srl
      image: ghcr.io/nokia/srlinux
      labels:
        topoViewer-role: spine
        <<: *spineGroup

    Spine-02:
      kind: srl
      image: ghcr.io/nokia/srlinux
      labels:
        topoViewer-role: spine
        <<: *spineGroup

    Leaf-01:
      kind: srl
      image: ghcr.io/nokia/srlinux
      labels:
        topoViewer-role: spine
        <<: *leafGroup

    Leaf-02:
      kind: srl
      image: ghcr.io/nokia/srlinux
      labels:
        topoViewer-role: spine
        <<: *leafGroup

[FloSch62]

haha, I was thinking about the same :)
I think we should support yaml anchors and do the validation after the yaml was processed, just to be really yaml compatible.

But also yaml anchors is a concept, not too many are aware of, it makes the yaml for some people quite unreadable