Server Metrics using Prometheus

Prometheus

What is Prometheus?

Prometheus is an "open-source monitoring system with a dimensional data model, flexible query language, efficient time series database and modern alerting approach".

Minetest has built-in support for prometheus, allowing you to see metrics about your server - such as player count and performance information.

Get or build the prometheus-cpp library

You may be able to find prometheus-cpp in your distro's package manager. Otherwise, you'll need to build it and make it available to Minetest.

Here's how you do that on Linux:

cd /tmp
git clone --recursive https://github.com/jupp0r/prometheus-cpp
mkdir prometheus-cpp/build
cd prometheus-cpp/build
cmake .. -DCMAKE_INSTALL_PREFIX=/usr/local -DCMAKE_BUILD_TYPE=Release -DENABLE_TESTING=0
make -j$(nproc)
sudo make install

Build Minetest

Now, you need build minetest with Prometheus enabled

cmake . -DENABLE_PROMETHEUS
make -j$(nproc)

Configure prometheus

Prometheus will make HTTP requests to Minetest's prometheus-cpp library to get the metrics.

You can set the prometheus listen address like so:

prometheus_listener_address = 127.0.0.1:30000

Grafana

You can link up Prometheus to Grafana to make nice web graphs. For example: rubenwardy.com