"Data source connected, but no labels received. Verify that Loki and Promtail is configured properly."
This error can appear in Grafana when you add Loki as a datasource. It means that Grafana can connect to Loki, but Loki has not received any logs from promtail. This can have several reasons:
- Promtail cannot reach Loki, check promtails output.
- Promtail started sending logs before Loki was ready. This can happen in test environments where promtail already read all logs and sent them off. You have two options:
- Start promtail later, e.g., 60 seconds
- Make sure new log messages are written after both promtail and Loki have started
The promtail configuration contains a __path__ entry to a directory that promtail cannot find.