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# Managing File Permissions for NetAlertX on Nginx with Docker

Tip

If you are facing permission issues, try to start the container without mapping your volumes. If that works, then the issue is permission related. You can try e.g., the following command: `docker run -d --rm --network=host \ -e TZ=Europe/Berlin \ -e PUID=200 -e PGID=200 \ -e PORT=20211 \ ghcr.io/jokob-sk/netalertx:latest`

NetAlertX runs on an Nginx web server. On Alpine Linux, Nginx operates as the `nginx` user (if PUID and GID environment variables are not specified, nginx user UID will be set to 102, and its supplementary group `www-data` ID to 82). Consequently, files accessed or written by the NetAlertX application are owned by `nginx:www-data`.

Upon starting, NetAlertX changes nginx user UID and www-data GID to specified values (or defaults), and the ownership of files on the host system mapped to `/app/config` and `/app/db` in the container to `nginx:www-data`. This ensures that Nginx can access and write to these files. Since the user in the Docker container is mapped to a user on the host system by ID:GID, the files in `/app/config` and `/app/db` on the host system are owned by a user with the same ID and GID (defaults are ID 102 and GID 82). On different systems, this ID:GID may belong to different users, or there may not be a group with ID 82 at all.

Option to set specific user UID and GID can be useful for host system users needing to access these files (e.g., backup scripts).

### Permissions Table for Individual Folders

Folder | User | User ID | Group | Group ID | Permissions | Notes
--- | --- | --- | --- | --- | --- | ---
`/app/config` | nginx | PUID (default 102) | www-data | PGID (default 82) | rwxr-xr-x | Ensure `nginx` can read/write; other users can read if in `www-data`
`/app/db` | nginx | PUID (default 102) | www-data | PGID (default 82) | rwxr-xr-x | Same as above