Monitor additional devices in bare metal environments

As a Cloud Operator, I want to be able to get metrics from external devices in my data center. This includes PDUs, UPSs and sensors (temperature, humidity, leakage, ...).

That means the monitoring architecture needs support for scraping such devices via SNMP or Modbus exporters (in case the monitoring is realized by Prometheus).
Different devices and sensors need specific exporter configurations which usually differ from data center to data center.

The monitoring somehow (= by providing ip address and type of the device) has to be aware of such devices to apply the correct device-specific exporter configuration and eventually scrape the targets.
Alternatively, the monitoring arch. must be able to get extended for supporting additional targets.
For instance by allowing to inject additional targets into configuration files of the monitoring architecture.