How to Set Up Promtail in Ubuntu 20.04

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:

   uname -a
   

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

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

3. Extract and Make Executable:

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

4. Move Binary to System Path:

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

5. Verify Installation:

   promtail --version
   

Step 2: Configure Promtail

1. Create Configuration Directory:

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

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

   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:

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

   Add the following content:

   [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:

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

3. Enable Service on Boot:

   sudo systemctl enable promtail.service
   

Step 4: Verify Logs

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

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.