14.11. Grafana Promtail¶
Official documentation website can be found here.
Promtail can read two different types of logs. Regular log files, or information from the Systemd journald.
14.11.1. Download promtail¶
Download
Extract
Copy to /usr/bin
Set ownership and permissions
# cd /tmp
# wget https://github.com/grafana/loki/releases/download/v3.0.0/promtail-linux-amd64.zip
# unzip promtail-linux-amd64.zip -d .
# mv promtail-linux-amd64 promtail
# cp promtail /usr/local/bin
14.11.2. Create system user¶
# useradd --system --no-create-home --shell /bin/false promtail
# usermod -G adm -a promtail # Add the "promtail" user, to the "adm" group if necessary.
14.11.3. Promtail configuration file¶
# Path: /etc/promtail/config.yml
server:
http_listen_port: 9080
grpc_listen_port: 0
positions:
filename: /tmp/positions.yaml
clients:
- url: http://localhost:3100/loki/api/v1/push
# Example for log file
scrape_configs:
- job_name: system
static_configs:
- targets:
- localhost
labels:
job: nginx
__path__: /var/log/nginx/*log # List here your log files
# Example for Systemd journald
scrape_configs:
- job_name: journal
journal:
json: true
path: /var/log/journal
labels:
job: systemd-journal
relabel_configs:
- source_labels: ['__journal__systemd_unit']
target_label: 'unit'
14.11.4. Promtail systemd service file¶
# Path: /etc/systemd/system/promtail.service
[Unit]
Description=Promtail service
After=network.target
[Service]
Type=simple
User=promtail
ExecStart=/usr/local/bin/promtail -config.file /etc/promtail/config.yml
# Give a reasonable amount of time for promtail to start up/shut down
TimeoutSec = 60
Restart = on-failure
RestartSec = 2
[Install]
WantedBy=multi-user.target
14.11.4.1. Start and enable Promtail¶
# systemctl enable --now promtail.service
# systemctl status promtail.service
14.11.5. Promtail temporary files¶
# cd /tmp
# touch positions.yaml
# chown promtail:promtail /tmp/positions.yaml
14.11.6. Grafana control panel¶
To check if Promtail is reading properly either your log files or the systemd journald units, you can click on the “Explore” section in the Grafana control panel, choose the right Loki connector, choose your desired log file or journald unit, and execute the query. If you see this is working (you can see the chunks of the big log files), you can convert this temporary query into a real Grafana “dashboard”, to continue working later with additional filtering options.