It can get boring playing singleplayer on a multiplayer server. So to maximize social play time I wrote a little server monitor widget for my polybar.

It's pretty simple, it starts with a python script:

from mcstatus import MinecraftServer as JavaServer
pvv = JavaServer.lookup("minecraft.pvv.ntnu.no")
dods = JavaServer.lookup("mc.dodsorf.as")
try:
pvv_status = pvv.status()
dods_status = dods.status()
except:
pass
result = ""
try:
if pvv_status.players.online > 0:
result += ("P" + str(pvv_status.players.online))
if dods_status > 0:
result += ("D" + str(pvv_status.players.online))
except:
pass
print(result)


When ran, this will output how many players are online, with a prefix denoting the server it is reporting on. Fetching the data via the mcstatus python library.

# Polybar🔗

My polybar is configured via home-manager - a tool for declaratively configuring user environments via Nix:

"module/minecraft" = {
type = "custom/script";

exec = "" + pkgs.writers.writePython3 "minecraft_status" { libraries = [ pkgs.python3.pkgs.mcstatus ]; flakeIgnore = [ "E722" ]; } ''
from mcstatus import MinecraftServer as JavaServer
pvv = JavaServer.lookup("minecraft.pvv.ntnu.no")
dods = JavaServer.lookup("mc.dodsorf.as")
try:
pvv_status = pvv.status()
dods_status = dods.status()
except:
pass
result = ""
try:
if pvv_status.players.online > 0:
result += ("P" + str(pvv_status.players.online))
if dods_status > 0:
result += ("D" + str(pvv_status.players.online))
except:
pass
print(result)
'';

interval = 10;
format = " <label>";
};


This is basically just the toml format for polybar converted to nix

I write the program inline using pkgs.writePython, configure the icon, and specify how often to run the script to fetch updates.
I think this is pretty cool, and an example of how flexible nix can be; writing a python script, specifying its dependencies, and just including that verbatim in your configuration file is pretty powerful stuff!

The result looks like this:

I've also made it so when you click on it, it sends a notification with a list of player names. See how that works in the full commit!.

I also used this technique to monitor my quota on PVV machines, this time with perl!
Note how this was specified in an entirely different nix file than the main polybar config - making this only available on PVV machines.

# Future work🔗

Deduplicating the code by using tail = true in polybar, and then just sending signals to it via kill to post the notification.