Oct 24, 2024 · Homelab / Intermediate · ~2 MIN READ

Grafana + Prometheus Home Lab Monitoring

Move from "is it up?" to "why is it slow?" — collect host and container metrics and build real dashboards.

Who This Is For

Intermediate.

Think of it like a hospital’s full vital-signs monitor instead of just checking someone’s pulse once. You’re not just confirming something’s alive, you can watch the trend and catch trouble before it becomes an emergency.

What You’ll Build

A Grafana dashboard showing metrics for at least one host and one container host.

Prerequisites

Docker host
At least one additional Linux host to monitor

Prometheus Architecture

Prometheus server, scrapes and stores metrics
Targets, the things being scraped
Exporters, expose metrics in a format Prometheus understands
Scrape interval, how often metrics are pulled

Deploy Prometheus and Grafana

$ services:
$   prometheus:
$     image: prom/prometheus:latest
$     ports: ["9090:9090"]
$   grafana:
$     image: grafana/grafana:latest
$     ports: ["3000:3000"]

Add Node Exporter to Each Host

$ docker run -d --name node-exporter -p 9100:9100 \
$   prom/node-exporter

Configure Scrape Targets

$ scrape_configs:
$   - job_name: "nodes"
$     static_configs:
$       - targets: ["host1:9100", "host2:9100"]

Add Prometheus as a Grafana Data Source

Grafana UI → Connections → Data Sources → Prometheus → point it at the Prometheus URL.

Essential Panels

CPU utilization
Load average
Memory usage
Disk capacity
Disk I/O
Network throughput
Container state

Set Alert Thresholds

Disk almost full
Sustained high CPU
Host unreachable
SMART warning fed in from a custom exporter

Security & Backup Notes

Monitor the monitoring stack itself, a Prometheus/Grafana outage is invisible unless something else is watching it

Troubleshooting

Prometheus can’t scrape an exporter, check the target is actually reachable on that port from the Prometheus host
Firewall blocks the metrics port, open it internally, never expose it publicly
Labels cause duplicate targets, check for accidental target overlap in your scrape config
Grafana dashboard has no data, verify the data source URL and that the query’s time range actually overlaps with when data exists

Lab Finish Line

Grafana dashboard showing at least one host and one container host.