Raspberry Pi Telegraf Setup with Docker

What is Telegraf?

Telegraf is a lightweight agent for collecting, processing, and reporting metrics and events from systems, sensors, and applications. With numerous input and output plugins, it’s perfect for monitoring Raspberry Pi metrics and integrating with databases like InfluxDB.

Why Use Docker for Telegraf?

Using Docker simplifies the setup process and provides:

1. Portability: Easily replicate your Telegraf setup on other devices.
2. Isolation: Run Telegraf independently of the host system.
3. Ease of Maintenance: Manage Telegraf with minimal system changes.

Prerequisites

To set up Telegraf on your Raspberry Pi, ensure you have:

• A Raspberry Pi running Raspberry Pi OS.
• Docker and Docker Compose installed.
• An output plugin endpoint like InfluxDB or Prometheus for metrics (optional but recommended).

Installing Docker on the Raspberry Pi

Step 1: Install Docker

If Docker is not installed, run the following commands:

curl -sSL https://get.docker.com | sh
sudo usermod -aG docker $USER

Reboot your Raspberry Pi to finalize the installation:

sudo reboot

Step 2: Install Docker Compose

To manage Telegraf with Docker Compose, install Docker Compose:

sudo apt update
sudo apt install -y docker-compose

Setting Up Telegraf with Docker Compose

Step 1: Create a Working Directory

Create a folder for Telegraf and navigate into it:

mkdir telegraf-docker && cd telegraf-docker

Step 2: Create a docker-compose.yml File

In the working directory, create a docker-compose.yml file:

services:
  telegraf:
    image: telegraf
    volumes:
      - ./telegraf.conf:/etc/telegraf/telegraf.conf
      - /var/run/docker.sock:/var/run/docker.sock
    restart: always
    hostname: "${HOSTNAME}"
    environment:
      - HOSTNAME=${HOSTNAME}
    privileged: true
networks:
  default:
    driver: bridge

This configuration mounts a telegraf.conf file and the Docker socket inside the container.

Step 3: Start the Container Temporarily

Run the following command to start the container:

docker-compose up -d

This starts a temporary Telegraf container without a configuration file. We’ll generate the configuration file next.

Step 4: Generate the Configuration File

Run this command to generate the default configuration file into the current directory:

docker exec telegraf telegraf config > telegraf.conf

• docker exec runs the telegraf config command inside the container.
• > redirects the output to a telegraf.conf file on the host.

Step 5: Edit the Configuration File

Customize the telegraf.conf file to suit your needs. For example:

nano telegraf.conf

Here’s a simple example configuration file:

[[inputs.cpu]]
  percpu = false

[[inputs.disk]]

[[inputs.mem]]

[[inputs.system]]

[[outputs.influxdb]]
  urls = ["http://192.168.1.10:8086"] # Replace with your InfluxDB endpoint
  database = "telegraf"

[agent]
  hostname = "${HOSTNAME}"

[[inputs.docker]]
  endpoint = "unix:///var/run/docker.sock"

Step 6: Restart the Container with the New Configuration

Stop the container and restart it to apply the updated configuration:

docker-compose down
docker-compose up -d

The container now uses the updated telegraf.conf file.

Verifying Telegraf is Running

Check the logs to ensure Telegraf is running correctly:

docker logs telegraf

You should see logs indicating successful metric collection and delivery to the configured output.

Integrating with InfluxDB

If you’re using InfluxDB as the output, ensure it’s set up and accessible. Here’s an example docker-compose.yml configuration for InfluxDB:

services:
  influxdb:
    image: influxdb:latest
    container_name: influxdb
    ports:
      - "8086:8086"
    volumes:
      - influxdb_data:/var/lib/influxdb
    restart: unless-stopped

volumes:
  influxdb_data:

Set the [outputs.influxdb] section in telegraf.conf to match your InfluxDB instance.

Adding Grafana for Visualization

To visualize the metrics collected by Telegraf, set up Grafana using the following docker-compose.yml file:

services:
  grafana:
    image: "grafana/grafana:latest"
    restart: unless-stopped
    user: "0"
    volumes:
      - ./grafana_data:/var/lib/grafana
    ports:
      - "3000:3000"
    environment:
      - GF_AUTH_DISABLE_LOGIN_FORM=true
      - GF_AUTH_ANONYMOUS_ENABLED=true
      - GF_AUTH_ANONYMOUS_ORG_ROLE=Admin

Start Grafana with:

docker-compose up -d

Access Grafana at http://<raspberrypi-ip>:3000 and log in with the default credentials (admin/admin).

Conclusion

Using Docker, setting up Telegraf on a Raspberry Pi is straightforward. By leveraging Docker Compose, you can easily manage the configuration file, update plugins, and integrate with tools like InfluxDB and Grafana for comprehensive monitoring and visualization.