Monitoring Your Server with Prometheus, Node Exporter, and Grafana Using Docker

In this tutorial, you’ll learn how to set up a comprehensive monitoring stack for your server using Prometheus, Node Exporter, and Grafana. We’ll use Docker to simplify the deployment and Nginx as a reverse proxy. Let’s dive in!

Prerequisites

• An Ubuntu server (we're using a Lightsail instance).
• Docker installed.
• Nginx installed and configured as a reverse proxy for your application.

1: Setting Up Docker Compose

First, create a directory for your monitoring setup:

mkdir -p ~/monitoring
cd ~/monitoring

Create a network for Prometheus and Grafana to communicate:

docker network create monitoring

Create a Docker Compose file (docker-compose.yml) with the following content:

version: '3'

services:
  node-exporter:
    image: prom/node-exporter
    container_name: node-exporter
    ports:
      - 9100:9100
    restart: unless-stopped
    networks:
      - monitoring

  prometheus:
    image: prom/prometheus
    container_name: prometheus
    volumes:
      - ./prometheus.yml:/etc/prometheus/prometheus.yml
    ports:
      - 9090:9090
    restart: unless-stopped
    networks:
      - monitoring

  grafana:
    image: grafana/grafana
    container_name: grafana
    ports:
      - 3000:3000
    environment:
      - GF_SERVER_ROOT_URL=%(protocol)s://%(domain)s:%(http_port)s/grafana/
      - GF_SERVER_SERVE_FROM_SUB_PATH=false
    restart: unless-stopped
    networks:
      - monitoring

networks:
  monitoring:
    driver: bridge

Next, create the Prometheus configuration file (prometheus.yml):

global:
  scrape_interval: 15s

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

2: Launch the Monitoring Stack

Run the Docker Compose stack:

docker-compose up -d

3: Configure Nginx as a Reverse Proxy

Open your Nginx configuration file:

sudo nano /etc/nginx/sites-available/default #use your domain instead of default if required.

Add the following server blocks for Prometheus and Grafana:

server {
    listen 80;

    server_name your-domain.com; # Replace with your domain

    location / {
        proxy_pass http://localhost:8080; # Your application
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto $scheme;
    }

    location /grafana/ { #subpath to use grafana
        proxy_pass http://localhost:3000/; 
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto $scheme;
    }
}

Save and close the file, then test the Nginx configuration:

sudo nginx -t

Reload Nginx to apply the changes:

sudo systemctl reload nginx

4: Access Grafana

1. Open your browser and go to http://your-domain.com/grafana/.
2. Log in with the default credentials (user: admin, password: admin).
3. Make sure to change the password when prompted.

Add Prometheus as a Data Source

1. Go to Connections > Data Sources.
2. Click on "Add data source" and select Prometheus.
3. Set the URL to http://prometheus:9090 and click "Save & Test".

Create Dashboards

You can now import pre-built dashboards or create your own. A good starting point is the Node Exporter Full dashboard.

Conclusion

Congratulations! You have successfully set up a powerful monitoring stack with Prometheus, Node Exporter, and Grafana using Docker, integrated with Nginx as a reverse proxy. Now you can monitor your server's performance and health in real-time. Happy monitoring!