Running Prometheus on Ubuntu 20.04 via docker

README.md

Prometheus on Ubuntu 20.04 via Docker

Installing Prometheus on a new server, I was a a bit confused that there seemed to be no good documentation on the main site for using it via Docker. There were also no instructions for running it via a custom PPA or someting, and the default pacakges installed via the package manager was a bit ouf of date?

What to do?

At first I tried running it via Docker, but then gave up, thinking it would be too much hassle to get the node exporter to access the host system for the metrics to be reported. There are various Googlejuice pages on manually installing and configuring a node, so this is what I did to start. But this still didn't 'feel' right.

So I asked around on Twitter, and got some very useful tips. The crucial one on running a node exporter in a container from Raffaele was actually the missing puzzle piece, and from there I could complete my setup. Thanks all!

So sharing it here as a complete setup, maybe someone else finds it useful. Might be good to post it upstream on the Prometheus site.

docker-compose.yml

version: "3.7"

services:
  node_exporter:
    image: prom/node-exporter
    container_name: prometheus_node
    volumes:
      - /proc:/host/proc:ro
      - /sys:/host/sys:ro
      - /:/rootfs:ro
    command:
      - "--path.procfs=/host/proc"
      - "--path.rootfs=/rootfs"
      - "--path.sysfs=/host/sys"
      - "--collector.filesystem.ignored-mount-points=^/(sys|proc|dev|host|etc)($$|/)"
    restart: always

  prometheus:
    image: myprometheus
    container_name: prometheus
    restart: always
    ports:
      - 9090:9090

Dockerfile

FROM prom/prometheus
ADD prometheus.yml /etc/prometheus/

prometheus.yml

global:
  scrape_interval:     15s # Set the scrape interval to every 15 seconds. Default is every 1 minute.
  evaluation_interval: 15s # Evaluate rules every 15 seconds. The default is every 1 minute.

scrape_configs:
  - job_name: node
    static_configs:
      - targets: ['node_exporter:9100']