Getting Synology SNMP data into Prometheus

With my new cameras installed, I have been spending a lot more time in the Diskstation Manager (DSM). I always forget how much actually goes on within the Synology, and I am reminded of that every time I open the Resource Monitor.

At some point, I started to wonder whether or not I could get this data into my metrics stack. A quick Google search brought me to the SNMP Exporter and the work Jinwoong Kim has done to generate a configuration file based on the Synology MIBs.

It took a bit of trial and error to get the configuration into the chart, mostly because I forgot how to make a multiline string in a Go template. I used the prometheus-snmp-exporter chart as a base, and built out a chart in my GitOps repo to have this deployed to my internal monitoring cluster.

After grabbing one of the community Grafana dashboards, this is what I got:

Security…. Not just yet

Apparently, SNMP has a few different versions. v1 and v2 are insecure, utilizing a community string for simple authentication. v3 has added a more complex authentication and encryption, but this makes configuration more complex.

Now, my original intent was to enable SNMPv3 on the Synology, however, I quickly realized that meant putting the auth values for SNMP v3 in my public configuration repo, as I haven’t figured out how to include that configuration as a secret (instead of a configmap). So, just to get things running, I settled on just enabling V1/V2 with the community string. These SNMP ports are blocked from external traffic, so I’m not too concerned with it, but my to-do list now includes a migration to SNMPv3 for the Synology.

When you have a hammer…

… everything looks like a nail. The SNMP Exporter I am currently running only has configuration for Synology, but the default if_mib module that is packaged with the SNMP Exporter can grab data from a number of products which support it. So I find myself looking for “nails” as it were, or objects from which I can gather SNMP data. For the time being, I am content with the Synology data, but don’t be surprised if my network switch and server find themselves on the end of SNMP collection. I would say that my Unifi devices warrant it, but the Unifi Poller I have running takes care of gathering that data.






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