Zabbix >=7.0 template for OPNsense via the REST API

[Garfieldttt]

Hi @all,

I have built a Zabbix template that monitors OPNsense through its own
REST API.

What it currently monitors:
- CPU: utilisation by user, system and interrupt, load per core
- Memory, swap, filesystems, temperature sensors
- pf: state table, source tracking, counters, table entries
- Ruleset: number of filter and NAT rules, evaluations per second,
  rules never matched, detection of rule changes
- Interfaces: throughput, packet rates, errors, link status, blocked packets
- Gateways: status, latency, packet loss
- Services: run state
- NTP: synchronisation, offset, stratum
- Kernel network memory (mbuf) and netisr queue drops
- Protocol errors at IP and TCP level
- Configuration changes and pending updates

Details, installation and privileges in the README:
https://github.com/Garfieldttt/opnsense-zabbix-api