Add persistent storage for Prometheus

homelab/server/config/monitoring/docker-compose.yml

@@ -2,7 +2,7 @@ version: '3'
 services:
     grafana:
         image: grafana/grafana-oss:latest
-        container_name: grafana_grafana
+        container_name: monitoring_grafana
         restart: unless-stopped
         networks:
             - monitoring
@@ -25,7 +25,8 @@ services:
         ports:
             -   9090:9090
         volumes:
-            -   ./prometheus.yml:/etc/prometheus/prometheus.yml
+            - ./prometheus.yml:/etc/prometheus/prometheus.yml
+            - ${DOCKER_DATA}/prometheus:/prometheus
         restart: unless-stopped
         command:
             -   "--config.file=/etc/prometheus/prometheus.yml"