L2SS-685: Expose the configured hostname from grafana (to f.e. alerta) instead of 'localhost'

docker-compose/grafana.yml

@@ -24,6 +24,8 @@ services:
     #  - grafana-configs:/etc/grafana
     ports:
       - "3000:3000"
+    environment:
+      - GF_SERVER_DOMAIN=${HOSTNAME}
     logging:
       driver: syslog
       options: