Monitoring: Improve labels for snmp-devices

[FFHener]

We currently use the OID .1.3.6.1.2.1.31.1.1.1.18 to get the labels of the ports. Unfortunantly I discovered that these labels exist for EdgeSwitch 10XP running 1.9.0 (latest), but not for EdgeSwitch 8XP running 2.2.1 (latest).

The only thing for labels I found at the first glance would be

IF-MIB::ifDescr.1 = STRING: Port 1
IF-MIB::ifDescr.2 = STRING: Port 2
[...]
IF-MIB::ifDescr.8 = STRING: Port 8
IF-MIB::ifDescr.11 = STRING: Management

which still might be an upgrade over the current thing defaulting to the Instance ID which would be 1 to 11.

I thing one path going forward could be to have one profile per device type which would require defining the explizit type in the config. Would be some work, but a nice preparation for furhter features like automated config for non-owrt-devices.

Another path could be to automate the snmp-Monitoring on the Grafana/Prometheus-Side - which would be an even bigger chunk of work. The first solution would enable us at least to go in smaller steps. Im happy for comments and opnions on this

[Noki]

I think the way to go is to describe every device in a model file in group_vars and move everything device related there (SNMP / DFS-Reset) and have every device described as a host. Maybe we can design the group vars file it in a way to use a template for settings that can be described for a set of devices (SNMP for airOS 8, switchOS, ...) but even having explicit settings per device would be fine in my opinion. We might even be able to override only a small set of the settings from a template or add more specific settings.