monitoring-stack

A ready-to-run observability stack for Linux hosts: Prometheus scrapes metrics from node_exporter, Alertmanager handles alerting, and Grafana ships with a pre-provisioned datasource and dashboard. docker compose up and you have monitoring — no manual clicking.

Stack

Component	Port	Role
Prometheus	9090	Metrics collection, storage, alert evaluation
node_exporter	9100	Host metrics (CPU, memory, disk, network)
Alertmanager	9093	Alert routing and notification
Grafana	3000	Dashboards (auto-provisioned)

Quick start

docker compose up -d

Service	URL	Login
Grafana	http://localhost:3000	admin / admin
Prometheus	http://localhost:9090	—
Alertmanager	http://localhost:9093	—

The Linux Host Overview dashboard (CPU, memory, root-FS usage, network) is provisioned automatically — open Grafana and it's already there.

Alerts

Defined in prometheus/alerts.yml and evaluated by Prometheus:

Alert	Condition
InstanceDown	a node_exporter target is unreachable for 1m
HighCpuLoad	CPU usage > 85% for 5m
LowDiskSpace	root filesystem < 15% free for 5m

Alertmanager ships with a no-op receiver — wire a Slack/email/webhook notifier in alertmanager/alertmanager.yml.

Monitoring more hosts

Install node_exporter on each target host and add it to the node job in prometheus/prometheus.yml:

  - job_name: "node"
    static_configs:
      - targets: ["node-exporter:9100", "10.0.0.10:9100", "10.0.0.11:9100"]

Layout

.
├── docker-compose.yml
├── prometheus/
│   ├── prometheus.yml        # scrape + alerting config
│   └── alerts.yml            # alert rules
├── alertmanager/
│   └── alertmanager.yml      # routing + receivers
└── grafana/
    ├── provisioning/         # datasource + dashboard providers
    └── dashboards/           # Linux Host Overview dashboard

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Part of my infrastructure & DevOps portfolio · runs on the lab from homelab-infrastructure.