ATM we're using Torrus (https://torrus.wikimedia.org) only for PDUs aggregates to report and track power usage. All of SNMP polling for network devices for example is handled inside librenms instead. I took a look at https://github.com/prometheus/snmp_exporter which recently got rewritten in Go and it might suit "PDU metrics" use case too.
Implementation would look like this:
* snmp_exporter deployed on the host(s) that will do SNMP polling
* Configure snmp_exporter with snmp community and a list of interesting OIDs to poll
** Including SNMP tables exported by the PDUs (i.e. described by this MIB http://www.circitor.fr/Mibs/Html/Sentry3-MIB.php)
* The exporter above exposes a `/snmp` endpoint over HTTP that will poll a specified "target" when asked
* Configure Prometheus to call the above endpoint for each PDU to monitor