VM Interface VLAN availibility when cluster and VLAN group scope is dcim.location

[Omripresent]

Deployment Type

Self-hosted

NetBox Version

v4.2.6

Python Version

3.12

Steps to Reproduce

1. Create a VLAN group with scope dcim.location and assign VLANs to that group
2. Create a VM cluster with scope dcim.location matching the VLAN group from step 1
3. Create a VM in the cluster from step 2
4. Create a VM interface in the VM from step 3
5. Attempt to assign a VLAN from step 1 to the VM interface from step 4

Expected Behavior

It is expected that VLANs associated with a VLAN group with a location scope will be able to be assigned to VM interfaces related to the same location

Observed Behavior

The VLANs of the matching location and VLAN group and not listed under either the untagged or tagged VLAN dropdowns

[Omripresent]

An update to the function get_for_virtualmachine can fix this issue.
Proposed change:

    def get_for_virtualmachine(self, vm):
        """
        Return all VLANs available to the specified VirtualMachine.
        """
        from .models import VLANGroup

        # Find all relevant VLANGroups
        q = Q()
        if vm.cluster:
            # Add VLANGroups scoped to the assigned cluster (or its group)
            q |= Q(
                scope_type=ContentType.objects.get_by_natural_key('virtualization', 'cluster'),
                scope_id=vm.cluster_id
            )
            if vm.cluster.group:
                q |= Q(
                    scope_type=ContentType.objects.get_by_natural_key('virtualization', 'clustergroup'),
                    scope_id=vm.cluster.group_id
                )
            if vm.cluster.scope_type == ContentType.objects.get_by_natural_key('dcim', 'location'):
                q |= Q(
                    scope_type=ContentType.objects.get_by_natural_key('dcim', 'location'),
                    scope_id__in=vm.cluster.scope.get_ancestors(include_self=True)
                )
        if vm.site:
            # Add VLANGroups scoped to the assigned location (or its site, group or region)
            q |= Q(
                scope_type=ContentType.objects.get_by_natural_key('dcim', 'site'),
                scope_id=vm.site.pk
            )
            if vm.site.region:
                q |= Q(
                    scope_type=ContentType.objects.get_by_natural_key('dcim', 'region'),
                    scope_id__in=vm.site.region.get_ancestors(include_self=True)
                )
            if vm.site.group:
                q |= Q(
                    scope_type=ContentType.objects.get_by_natural_key('dcim', 'sitegroup'),
                    scope_id__in=vm.site.group.get_ancestors(include_self=True)
                )
        vlan_groups = VLANGroup.objects.filter(q)

        # Return all applicable VLANs
        q = (
            Q(group__in=vlan_groups) |
            Q(group__scope_id__isnull=True, site__isnull=True) |  # Global group VLANs
            Q(group__isnull=True, site__isnull=True)  # Global VLANs
        )
        if vm.site:
            q |= Q(site=vm.site)

        return self.filter(q)

This doesn't account for VLAN groups scoped to a specific rack, that could be more problematic to solve since the "smallest" scope of a cluster is location. Therefore I think that lookup by rack is not feasible.

[jnovinger]

@Omripresent , thanks for the report. I think I agree with your statement about lookup by rack not being feasible.

Would you like to take this on?

[Omripresent]

I'd be happy to. I ran some basic tests for my use case but I'll extend it before submitting a PR