added note about docker gid

README.md

@@ -8,3 +8,10 @@ Various tools to monitor Docker containers
 - `INFLUX_WRITE_TOKEN`
 - `INFLUX_HOST`
 - `LOKI_HOST`
+
+## Setup
+
+```shell
+root@docker:~/docker-observation# getent group docker
+docker:x:995:root
+```

docker-compose.yml

@@ -3,7 +3,7 @@ services:
   telegraf-docker:
     image: telegraf
     restart: unless-stopped
-    user: root:996
+    user: root:995
     env_file:
       - .env
     volumes: