Loki doesn’t actually forward things, other things simply talk to it via its API. Promtail sends it logs to aggregate, Grafana sends it queries to answer.
So if you have Grafana running on another machine then all you have to do is this:
- List a port to expose on the host for the ‘HTTP Listen Port’ in the Network configuration options of the Loki add-on
- Open Grafana and add a Loki data source. For URL put the hostname or IP address of your HA server and then put the port you listed
Then that’s it. Grafana will send all of its queries over to Loki as you put them in the UI.
Is that what you want or were you hoping to get the logs off of HA and onto another machine so you could explore them without depending on the HA machine? If that’s the case then what you want I believe is install the promtail add-on but self-host Loki elsewhere (probably on your Debian 10 server). Then set up promtail to ship the logs over to the other machine so Grafana and Loki can just do their thing in isolation.