Promtail is an essential tool for shipping logs from your applications to a Loki instance. When integrated with Grafana, it enables seamless log aggregation and monitoring. This guide walks you through installing and configuring Promtail on Ubuntu 20.04.

Prerequisites

  1. Loki and Grafana are already configured.
  2. A running application to monitor (e.g., NGINX in this example).

Step 1: Install Promtail

  1. Check Your CPU Architecture:

    bash
    uname -a

  2. Download the Promtail Binary: Replace amd64 with your system’s architecture if different.

    bash
    curl -O -L "https://github.com/grafana/loki/releases/download/v2.4.1/promtail-linux-amd64.zip"

  3. Extract and Make Executable:

    bash
    unzip "promtail-linux-amd64.zip"
chmod a+x "promtail-linux-amd64"

  4. Move Binary to System Path:

    bash
    sudo cp promtail-linux-amd64 /usr/local/bin/promtail

  5. Verify Installation:

    bash
    promtail --version

Step 2: Configure Promtail

  1. Create Configuration Directory:

    bash
    sudo mkdir -p /etc/promtail /etc/promtail/logs

  2. Download Example Configuration File: This example config is optimized for NGINX logs.

    bash
    sudo curl -o /etc/promtail/promtail-config.yaml -L "https://gist.githubusercontent.com/theLazyCat775/6fe9125e529221166e9f02b00244638a/raw/84f510e6f62d0e60ab95dbe7f9732a629a27eb6d/promtail-config.yaml"

Step 3: Run Promtail as a Service

  1. Create a Systemd Service File:

    bash
    sudo vi /etc/systemd/system/promtail.service

    Add the following content:

    ini
    [Unit]
Description=Promtail service
After=network.target

[Service]
Type=simple
User=root
ExecStart=/usr/local/bin/promtail -config.file /etc/promtail/promtail-config.yaml
Restart=on-failure
RestartSec=20
StandardOutput=append:/etc/promtail/logs/promtail.log
StandardError=append:/etc/promtail/logs/promtail.log

[Install]
WantedBy=multi-user.target

  2. Enable and Start the Service:

    bash
    sudo systemctl daemon-reload
sudo systemctl start promtail
sudo systemctl status promtail

  3. Enable Service on Boot:

    bash
    sudo systemctl enable promtail.service

Step 4: Verify Logs

Check Promtail logs to ensure it is shipping logs to the Loki instance:

bash
sudo tail -f /etc/promtail/logs/promtail.log

Conclusion

Promtail is now successfully installed and running as a service on Ubuntu 20.04. It is actively monitoring your application (NGINX in this case) and shipping logs to Loki for aggregation. Pair it with Grafana for powerful visualization and monitoring.

Need More Help? If you encounter issues or have specific requirements, feel free to reach out in the comments or connect on Twitter.