add subfolder env var docs and set home on backend launch

README.md

@@ -89,6 +89,7 @@ services:
       - PUID=1000
       - PGID=1000
       - TZ=Europe/London
+      - SUBFOLDER=/ #optional
     volumes:
       - /path/to/data:/data
     ports:
@@ -106,6 +107,7 @@ docker run -d \
   -e PUID=1000 \
   -e PGID=1000 \
   -e TZ=Europe/London \
+  -e SUBFOLDER=/ `#optional` \
   -p 3000:3000 \
   -p 80:80 \
   -p 4001:4001 `#optional` \
@@ -126,6 +128,7 @@ Container images are configured using parameters passed at runtime (such as thos
 | `-e PUID=1000` | for UserID - see below for explanation |
 | `-e PGID=1000` | for GroupID - see below for explanation |
 | `-e TZ=Europe/London` | Specify a timezone to use EG Europe/London |
+| `-e SUBFOLDER=/` | Specify a subfolder for reverse proxies IE '/FOLDER/' |
 | `-v /data` | Path to store roms/artwork |
 
 ## Environment variables from files (Docker secrets)

readme-vars.yml

@@ -30,6 +30,9 @@ param_env_vars:
 opt_param_usage_include_ports: true
 opt_param_ports:
   - { external_port: "4001", internal_port: "4001", port_desc: "IPFS peering port, if you want to participate in the P2P network to distribute frontend artwork please forward this to the Internet" }
+opt_param_usage_include_env: true
+opt_param_env_vars:
+  - { env_var: "SUBFOLDER", env_value: "/", desc: "Specify a subfolder for reverse proxies IE '/FOLDER/'"}
 
 # application setup block
 app_setup_block_enabled: true

root/etc/services.d/backend/run

@@ -1,5 +1,5 @@
 #!/usr/bin/with-contenv bash
 
 cd /emulatorjs || exit
-exec \
+HOME=/data exec \
     s6-setuidgid abc node index.js