As I suggested during the livestream, let’s share some interesting things that we monitor (or monitored before) and vote for the ones that sound the most interesting!
If you receive the most reactions are located in the US or EU, we will also be able to send a little souvenir from Checkmk
Feel free to reply with your coolest monitored thing. I will start: together with @mschlenker at different events we monitored the soil humidity of our Checkmk plant Root-y
Not fully functional yet, but I am slowly building out an automated control of my three minisplit heat pumps centered around Checkmk.
I am using generic 433 MHz wireless thermometers, and a software defined radio passed through to an LXC container that listens to their beacons. A custom Python script turns the beacons into files that a Checkmk local agent plugin scrapes on poll. Finally, that data is ingested by a custom agent_based.v2 plugin allowing me to run a service discovery and choose which thermometers I want to monitor or disable from the UI.
I finally got local control of the actual minisplits working, and working within HomeAssistant. Now that I can control them locally, I’m working on Python scripts that will be usable as Alert Handlers to adjust the temperature and mode based on the state of the thermometers.
I am going through all this because these minisplits don’t have an “auto” mode that will adjust between cooling and heating as needed. I am very bothered by having to manually change from cool to heat and back again every day, potentially multiple times per day during the spring and fall when the temperature swings wildly.
At this Checkmk conference we had CO2 monitoring with Sensirion SCD30 sensor boards (Watterott CO2 Ampel). Since we had not-so-good experiences with the ATWINC1500 WiFi modules, we switched to LoRa transceivers two years ago. The senders just send a raw JSON string.
As for somewhat more exotic, nerdy and non-infra things I use the monitoring for:
I, too, have (selfmade) CO2 sensor devices, using MH-Z19B sensors and ESP32s. These have displays and RGB LED rings to indicate CO2 levels and also log the data to a database. I use my personal CMK to alert me when it’s time to let some fresh air in. Here’s a small version:
I also made wired and wireless weather sensor devices with ESP32s and temperature/humidity sensors. I use CMK to alert on low battery voltage for the wireless ones.
I’ve put one of them in my fridge and alert when it gets too warm, because it has happened more than once that someone didn’t close the door properly.
Another is in the room I let my laundry dry in and CMK alerts when humidity exceeds the threshold to prevent mold in winter.
My GF runs a raspberry pi with a DVB-T stick outside to receive ADS-B data and track airplanes. My CMK monitors that the services run and reports how many aircraft it has seen.
I’ve made a special agent for video projectors (“beamer”) with lamps etc. That uses the PJLink protocol (my fork of the lib is here: GitHub - FlorianHeigl/pypjlink: PJLink is a standard for controlling data projectors. · GitHub , and I uploaded the agent as a gist: PJ-Link special agent · GitHub (i’m sorry that I can’t tell you if it’s the latest version, my memory is very bad))
Another cute thing to monitor is the uplinks on a Dragino LoraWAN gateway. I’m running the agent over SSH on that, but for the online status (wifi, lan, lora) I parse their status page.
Next is one for samsung screens using “MDC” and one that also needs to come off the TODO list is Balena cloud.
Those are the shiny blinky things at Dokumentation Obersalzberg, basically the CheckMK monitoring is watching the status of the old bunker of Hitlers holiday residence
Silly fact: Due to the contents when a projector is to be picked up for repair we give them different less offensive names on the UPS shipping label
I run two monitoring sites, one has the virt cluster and external things like uplink firewalls etc, unifi wifi etc.
the second is only exhibition related assets.
I had an android tablet at my wall with a checkmk dashboard, so others can check the status if I’m not there, but Android just logged out or updated or whatever all the time. So I removed it for the moment.
Not sure what to do, a fullscreen Nastamon is too technical for historians and maintenance staff etc.
Since I learned to use Samsung MDC I’m kinda a bit fan of just showing tickets on info displays, maybe I’ll do that, make BI services and run a ticker if one of those fails (like the munich subway does)
In more silly setups I got one site that monitors marvell smartnics, it base64’s the agent and executes it as stdin on the remote end (Basti did that first in 2012, I just made it “prod-grade” it with the base64). the agent is modified a bit for linux/mips. I got a side project to make a proper AlpineLinux port to those CPUs, whenever it is done I’ll have the agent inclucded.
This was supposed to be just an activity for the livestream, but I like how this is going and what you are sharing!
Let’s prolong this until July! Keep sharing and whoever gets the most reactions, gets a little souvenir from Checkmk (but now we can only send within the EU unfortunately). I will be back on the 6th of July after a short vacation and we see who gets it
