an agent which ships the contents of local logs to a private Grafana Loki instance or Grafana Cloud. It is usually deployed to every machine that runs applications which need to be monitored.
It primarily:
Discovers targets
Attaches labels to log streams
Pushes them to the Loki instance.
Currently, Promtail can tail logs from two sources: local log files and the systemd journal (on AMD64 machines only).