Add Loki, Promtail, and Grafana services for observability stack

docker/docker-compose.prod.yml

@@ -61,11 +61,58 @@ services:
       timeout: 10s
       retries: 3
 
+  # Optional local observability stack (can be enabled on servers that
+  # should run Loki/Grafana). These services use configs found under
+  # the repository `docker/` directory so the same config works in dev.
+  loki:
+    image: grafana/loki:2.8.2
+    command: -config.file=/etc/loki/local-config.yaml
+    ports:
+      - "3100:3100"
+    volumes:
+      - ./loki-config/local-config.yaml:/etc/loki/local-config.yaml:ro
+      - ../docker/loki-data:/loki
+      # WAL directory: map a host folder so Loki (running as UID 10001)
+      # can create the write-ahead log. Host folder created under
+      # `docker/loki-wal` and owned by UID 10001.
+      - ../docker/loki-wal:/wal
+    restart: unless-stopped
+    healthcheck:
+      test: ["CMD-SHELL", "wget -qO- http://localhost:3100/ready || exit 1"]
+      interval: 10s
+      timeout: 5s
+      retries: 6
+
+  promtail:
+    image: grafana/promtail:2.8.2
+    volumes:
+      # In prod you may want to point this at the host system log directory.
+      - ../logs:/var/log/rad:ro
+      - ./promtail-config.yml:/etc/promtail/promtail-config.yml:ro
+    command: -config.file=/etc/promtail/promtail-config.yml
+    depends_on:
+      - loki
+    restart: unless-stopped
+
+  grafana:
+    image: grafana/grafana:10.2.0
+    ports:
+      - "3000:3000"
+    environment:
+      - GF_SECURITY_ADMIN_PASSWORD=admin
+    volumes:
+      - grafana-data:/var/lib/grafana
+    depends_on:
+      loki:
+        condition: service_healthy
+    restart: unless-stopped
+
 volumes:
   postgres_data:
   redis_data:
   static_volume:
   media_volume:
+  grafana-data:
 
 networks:
   default:

docker/loki-config/local-config.yaml

@@ -0,0 +1,43 @@
+server:
+  http_listen_port: 3100
+  grpc_listen_port: 9095
+
+ingester:
+  lifecycler:
+    address: 127.0.0.1
+    ring:
+      kvstore:
+        store: inmemory
+      replication_factor: 1
+  chunk_idle_period: 5m
+  chunk_retain_period: 30s
+  max_transfer_retries: 0
+
+schema_config:
+  configs:
+    - from: 2020-10-24
+      store: boltdb-shipper
+      object_store: filesystem
+      schema: v11
+      index:
+        prefix: index_
+        period: 24h
+
+storage_config:
+  boltdb_shipper:
+    active_index_directory: /loki/index
+    cache_location: /loki/cache
+    shared_store: filesystem
+  filesystem:
+    directory: /loki/chunks
+
+# Compactor settings: ensure compactor working directory is inside the mounted
+# `/loki` path so the process (running as UID 10001) can create files.
+compactor:
+  working_directory: /loki/compactor
+  shared_store: filesystem
+
+limits_config:
+  enforce_metric_name: false
+
+auth_enabled: false

docker/loki-data/chunks/loki_cluster_seed.json

@@ -0,0 +1 @@
+{"UID":"f8cade59-3cf9-4ae3-965d-8b0a57007d58","created_at":"2025-12-01T17:14:05.101735276Z","version":{"version":"2.8.2","revision":"9f809eda7","branch":"HEAD","buildUser":"root@e401cfcb874f","buildDate":"2023-05-03T11:07:54Z","goVersion":"go1.20.4"}}