Monitoring Your Raspberry Pi with Prometheus and Grafana

This guide provides a step-by-step process to set up Prometheus, Node Exporter, and Grafana on a Raspberry Pi for monitoring system metrics like CPU, memory, and temperature on your local network. Ideal for DevOps beginners or Raspberry Pi enthusiasts exploring observability.

Tested on a Raspberry Pi running Raspbian GNU/Linux 12 (bookworm).

Why Monitor Your Raspberry Pi?

• Prometheus: A time-series database for collecting and storing metrics.
• Node Exporter: Gathers system metrics (CPU, memory, disk, etc.) for Prometheus.
• Grafana: Visualizes metrics through customizable dashboards.

Together, these tools enable real-time performance tracking with insightful visualizations.

Prerequisites

• Raspberry Pi with Raspbian installed.
• SSH enabled (sudo raspi-config > Interface Options > SSH > Enable).
• Basic terminal familiarity.
• Pi’s local IP address (find it with hostname -I).

Step 1: Update Your Raspberry Pi

Ensure your system is up-to-date to prevent compatibility issues:

sudo apt update && sudo apt upgrade -y

Step 2: Install Prometheus

Prometheus collects and stores metrics. We'll install it for the Pi’s ARMv7 architecture.

1. Create a Prometheus user for security:

   sudo useradd --no-create-home --shell /bin/false prometheus

2. Download Prometheus (replace v2.53.0 with the latest linux-armv7 version from Prometheus downloads):

   cd /tmp
   wget https://github.com/prometheus/prometheus/releases/download/v2.53.0/prometheus-2.53.0.linux-armv7.tar.gz
   tar xvfz prometheus-2.53.0.linux-armv7.tar.gz
   cd prometheus-2.53.0.linux-armv7

3. Install binaries:

   sudo cp prometheus promtool /usr/local/bin/
   sudo chown prometheus:prometheus /usr/local/bin/prometheus /usr/local/bin/promtool

4. Set up directories and configuration:

   sudo mkdir /etc/prometheus /var/lib/prometheus
   sudo chown prometheus:prometheus /etc/prometheus /var/lib/prometheus
   sudo nano /etc/prometheus/prometheus.yml

5. Paste the following configuration to scrape Prometheus and Node Exporter:

   global:
     scrape_interval: 15s
   
   scrape_configs:
     - job_name: 'prometheus'
       static_configs:
         - targets: ['localhost:9090']
     - job_name: 'node'
       static_configs:
         - targets: ['localhost:9100']

   Save with Ctrl+O, Enter, then Ctrl+X.

6. Create a systemd service:

   sudo nano /etc/systemd/system/prometheus.service

   Paste:

   [Unit]
   Description=Prometheus
   Wants=network-online.target
   After=network-online.target
   
   [Service]
   User=prometheus
   Group=prometheus
   Type=simple
   ExecStart=/usr/local/bin/prometheus \
     --config.file /etc/prometheus/prometheus.yml \
     --storage.tsdb.path /var/lib/prometheus/ \
     --web.console.templates=/etc/prometheus/consoles \
     --web.console.libraries=/etc/prometheus/console_libraries
   
   [Install]
   WantedBy=multi-user.target

   Save, then enable and start the service:

   sudo systemctl daemon-reload
   sudo systemctl start prometheus
   sudo systemctl enable prometheus

7. Verify Prometheus:

   • On a device on the same network, visit http://<pi-local-ip>:9090 (replace <pi-local-ip> with your Pi’s IP).
   • Query up in the Prometheus UI to confirm it’s running.

Step 3: Install Node Exporter

Node Exporter collects system metrics for Prometheus.

1. Download Node Exporter (replace v1.8.2 with the latest linux-armv7 version from Prometheus downloads):

   cd /tmp
   wget https://github.com/prometheus/node_exporter/releases/download/v1.8.2/node_exporter-1.8.2.linux-armv7.tar.gz
   tar xvfz node_exporter-1.8.2.linux-armv7.tar.gz
   cd node_exporter-1.8.2.linux-armv7

2. Install and configure:

   sudo cp node_exporter /usr/local/bin/
   sudo useradd --no-create-home --shell /bin/false node_exporter
   sudo chown node_exporter:node_exporter /usr/local/bin/node_exporter

3. Create a systemd service:

   sudo nano /etc/systemd/system/node_exporter.service

   Paste:

   [Unit]
   Description=Prometheus Node Exporter
   Wants=network-online.target
   After=network-online.target
   
   [Service]
   User=node_exporter
   Group=node_exporter
   Type=simple
   ExecStart=/usr/local/bin/node_exporter
   
   [Install]
   WantedBy=multi-user.target

   Save, then enable and start the service:

   sudo systemctl daemon-reload
   sudo systemctl start node_exporter
   sudo systemctl enable node_exporter

4. Verify Node Exporter:

   • Visit http://<pi-local-ip>:9100/metrics to see raw metrics (CPU, memory, etc.).
   • In Prometheus (http://<pi-local-ip>:9090), query up to confirm the node job is 1.

Step 4: Install Grafana

Grafana visualizes Prometheus metrics in dashboards.

1. Add the Grafana repository:

   sudo apt install -y apt-transport-https software-properties-common wget
   sudo mkdir -p /etc/apt/keyrings/
   wget -q -O - https://apt.grafana.com/gpg.key | gpg --dearmor | sudo tee /etc/apt/keyrings/grafana.gpg > /dev/null
   echo "deb [signed-by=/etc/apt/keyrings/grafana.gpg] https://apt.grafana.com stable main" | sudo tee /etc/apt/sources.list.d/grafana.list
   sudo apt update

2. Install and start Grafana:

   sudo apt install grafana -y
   sudo systemctl start grafana-server
   sudo systemctl enable grafana-server

3. Access Grafana:

   • Visit http://<pi-local-ip>:3000 and log in with admin/admin (change the password when prompted).

4. Connect Grafana to Prometheus:

   • Go to Configuration (gear icon) > Data Sources > Add data source > Prometheus.
   • Set the URL to http://localhost:9090.
   • Click Save & Test (should confirm “Data source is working”).

5. Create a dashboard:

   • Go to + > Dashboard > Add visualization.
   • Select the Prometheus data source.
   • Try queries like:
     • rate(node_cpu_seconds_total{mode="user"}[5m]) (CPU usage)
     • node_hwmon_temp_celsius (Pi temperature)
   • Save as “Pi Monitoring”.

Step 5: Explore Your Metrics

• Open Grafana (http://<pi-local-ip>:3000) and view your “Pi Monitoring” dashboard.
• Example metrics to visualize:
  • CPU: rate(node_cpu_seconds_total{mode="user"}[5m])
  • Memory: node_memory_MemAvailable_bytes / node_memory_MemTotal_bytes * 100
  • Temperature: node_hwmon_temp_celsius

Add more panels to customize your dashboard and monitor your Pi’s performance.

Troubleshooting

• Prometheus not running? Check logs: sudo journalctl -u prometheus
• Node Exporter down? Verify status: sudo systemctl status node_exporter
• Grafana not loading? Check status: sudo systemctl status grafana-server
• Firewall issues? Allow ports: sudo ufw allow 9090, sudo ufw allow 9100, sudo ufw allow 3000