Allow splitting config, downloads and media paths via .env

Adds optional CONFIG_DIR, DOWNLOADS_DIR and MEDIA_DIR env variables so
users can spread configs, downloads and media across different drives
without restructuring ROOT_DIR. Each falls back to its ROOT_DIR-based
default when left empty, so existing setups keep working unchanged.

The -arr services (sonarr, radarr, lidarr, mylar3) now use a single
${DOWNLOADS_DIR}:/data parent bind with a ${MEDIA_DIR}:/data/media
overlay. This preserves TRaSH's single-/data-mount semantics inside
the container (hardlinks still work on one filesystem) while letting
the host-side media tree live wherever the user wants.

README documents the new variables, the generated folder structure,
recommended storage layouts, and the same-filesystem requirement for
hardlinks between downloads and media.

docker-compose.yml.sample

@@ -10,8 +10,12 @@ services:
       - UMASK=002
       - TZ=${TIMEZONE}
     volumes:
-      - ${ROOT_DIR}/config/sonarr-config:/config
-      - ${ROOT_DIR}/data:/data
+      - ${CONFIG_DIR:-${ROOT_DIR}/config}/sonarr-config:/config
+      # Single /data parent mount (TRaSH-style) + MEDIA_DIR overlay at /data/media.
+      # When MEDIA_DIR is left at its default, the overlay is redundant but harmless;
+      # when overridden, it transparently redirects /data/media to the new location.
+      - ${DOWNLOADS_DIR:-${ROOT_DIR}/data}:/data
+      - ${MEDIA_DIR:-${ROOT_DIR}/data/media}:/data/media
     ports:
       - "8989:8989"
     restart: unless-stopped
@@ -25,8 +29,9 @@ services:
       - UMASK=002
       - TZ=${TIMEZONE}
     volumes:
-      - ${ROOT_DIR}/config/radarr-config:/config
-      - ${ROOT_DIR}/data:/data
+      - ${CONFIG_DIR:-${ROOT_DIR}/config}/radarr-config:/config
+      - ${DOWNLOADS_DIR:-${ROOT_DIR}/data}:/data
+      - ${MEDIA_DIR:-${ROOT_DIR}/data/media}:/data/media
     ports:
       - "7878:7878"
     restart: unless-stopped
@@ -40,8 +45,9 @@ services:
       - UMASK=002
       - TZ=${TIMEZONE}
     volumes:
-      - ${ROOT_DIR}/config/lidarr-config:/config
-      - ${ROOT_DIR}/data:/data
+      - ${CONFIG_DIR:-${ROOT_DIR}/config}/lidarr-config:/config
+      - ${DOWNLOADS_DIR:-${ROOT_DIR}/data}:/data
+      - ${MEDIA_DIR:-${ROOT_DIR}/data/media}:/data/media
     ports:
       - "8686:8686"
     restart: unless-stopped
@@ -54,8 +60,9 @@ services:
       - PGID=${MEDIACENTER_GID}
       - UMASK=002
     volumes:
-      - ${ROOT_DIR}/config/mylar-config:/config
-      - ${ROOT_DIR}/data:/data
+      - ${CONFIG_DIR:-${ROOT_DIR}/config}/mylar-config:/config
+      - ${DOWNLOADS_DIR:-${ROOT_DIR}/data}:/data
+      - ${MEDIA_DIR:-${ROOT_DIR}/data/media}:/data/media
     ports:
       - "8090:8090"
     restart: unless-stopped
@@ -67,10 +74,10 @@ services:
       - user=${AUDIOBOOKSHELF_UID}:${MEDIACENTER_GID}
       - TZ=${TIMEZONE}
     volumes:
-      - ${ROOT_DIR}/config/audiobookshelf:/config
-      - ${ROOT_DIR}/data/media/audiobooks:/audiobooks
-      - ${ROOT_DIR}/data/media/podcasts:/podcasts
-      - ${ROOT_DIR}/data/media/audiobookshelf-metadata:/metadata
+      - ${CONFIG_DIR:-${ROOT_DIR}/config}/audiobookshelf:/config
+      - ${MEDIA_DIR:-${ROOT_DIR}/data/media}/audiobooks:/audiobooks
+      - ${MEDIA_DIR:-${ROOT_DIR}/data/media}/podcasts:/podcasts
+      - ${MEDIA_DIR:-${ROOT_DIR}/data/media}/audiobookshelf-metadata:/metadata
     ports:
       - "13378:80"
     restart: unless-stopped
@@ -83,8 +90,8 @@ services:
       - PGID=${MEDIACENTER_GID}
       - TZ=${TIMEZONE}
     volumes:
-      - ${ROOT_DIR}/config/bazarr-config:/config
-      - ${ROOT_DIR}/data/media:/media
+      - ${CONFIG_DIR:-${ROOT_DIR}/config}/bazarr-config:/config
+      - ${MEDIA_DIR:-${ROOT_DIR}/data/media}:/media
     ports:
       - "6767:6767"
     restart: unless-stopped
@@ -98,7 +105,7 @@ services:
       - UMASK=002
       - TZ=${TIMEZONE}
     volumes:
-      - ${ROOT_DIR}/config/overseerr-config:/app/config
+      - ${CONFIG_DIR:-${ROOT_DIR}/config}/overseerr-config:/app/config
     ports:
       - "5055:5055"
     restart: unless-stopped
@@ -112,7 +119,7 @@ services:
       - UMASK=002
       - TZ=${TIMEZONE}
     volumes:
-      - ${ROOT_DIR}/config/jellyseerr-config:/app/config
+      - ${CONFIG_DIR:-${ROOT_DIR}/config}/jellyseerr-config:/app/config
     ports:
       - "5056:5055"
     restart: unless-stopped
@@ -126,7 +133,7 @@ services:
       - UMASK=002
       - TZ=${TIMEZONE}
     volumes:
-      - ${ROOT_DIR}/config/prowlarr-config:/config
+      - ${CONFIG_DIR:-${ROOT_DIR}/config}/prowlarr-config:/config
     ports:
       - "9696:9696"
     restart: unless-stopped
@@ -142,7 +149,7 @@ services:
       - SECRET_ENCRYPTION_KEY=
     ports:
       - "7575:7575"
-  
+
   jackett:
     image: lscr.io/linuxserver/jackett:latest
     container_name: jackett
@@ -150,9 +157,9 @@ services:
       - PUID=${JACKETT_UID}
       - PGID=${MEDIACENTER_GID}
       - UMASK=002
-      - TZ=${TIMEZONE}    
+      - TZ=${TIMEZONE}
     volumes:
-      - ${ROOT_DIR}/config/jackett-config:/config
+      - ${CONFIG_DIR:-${ROOT_DIR}/config}/jackett-config:/config
     ports:
       - 9117:9117
     restart: unless-stopped
@@ -179,22 +186,22 @@ services:
       - VERSION=docker
       - PLEX_CLAIM=${PLEX_CLAIM}
     volumes:
-      - ${ROOT_DIR}/config/plex-config:/config
-      - ${ROOT_DIR}/data/media:/media
+      - ${CONFIG_DIR:-${ROOT_DIR}/config}/plex-config:/config
+      - ${MEDIA_DIR:-${ROOT_DIR}/data/media}:/media
     restart: unless-stopped
 
   tautulli:
     image: lscr.io/linuxserver/tautulli:latest
     container_name: tautulli
     # commented out because plex can also run outside of docker
-    #depends_on: 
+    #depends_on:
     #  - plex
     environment:
       - PUID=${UID}
       - PGID=${MEDIACENTER_GID}
       - TZ=${TIMEZONE}
     volumes:
-      - ${ROOT_DIR}/config/tautulli-config:/config
+      - ${CONFIG_DIR:-${ROOT_DIR}/config}/tautulli-config:/config
     ports:
       - "8181:8181"
     restart: unless-stopped
@@ -208,8 +215,8 @@ services:
       - UMASK=002
       - TZ=${TIMEZONE}
     volumes:
-      - ${ROOT_DIR}/config/jellyfin-config:/config
-      - ${ROOT_DIR}/data/media:/data
+      - ${CONFIG_DIR:-${ROOT_DIR}/config}/jellyfin-config:/config
+      - ${MEDIA_DIR:-${ROOT_DIR}/data/media}:/data
     ports:
       - "8096:8096"
     restart: unless-stopped
@@ -224,8 +231,8 @@ services:
       - TZ=${TIMEZONE}
       - WEBUI_PORT=8080
     volumes:
-      - ${ROOT_DIR}/config/qbittorrent-config:/config
-      - ${ROOT_DIR}/data/torrents:/data/torrents
+      - ${CONFIG_DIR:-${ROOT_DIR}/config}/qbittorrent-config:/config
+      - ${DOWNLOADS_DIR:-${ROOT_DIR}/data}/torrents:/data/torrents
     ports:
       - "8080:8080"
       - "6881:6881"
@@ -241,8 +248,8 @@ services:
       - UMASK=002
       - TZ=${TIMEZONE}
     volumes:
-      - ${ROOT_DIR}/config/sabnzbd-config:/config
-      - ${ROOT_DIR}/data/usenet:/data/usenet
+      - ${CONFIG_DIR:-${ROOT_DIR}/config}/sabnzbd-config:/config
+      - ${DOWNLOADS_DIR:-${ROOT_DIR}/data}/usenet:/data/usenet
     ports:
       - "8081:8080"
     restart: unless-stopped