Auto-update/Alter running application files with silverblue

Hello there!

I’m having a particular issue. I’m creating my first flatpack and it is for a java-based application. How it works is that it has a stable version on the internet and when you start it, it creates a folder null in the current directory which it then just overwrites some libs, updating it next time it is ran.

For now I put the application and it’s lib folder under /app/share/<appname>. Now, I am getting an error that my system is Read-Only, I don’t know whether this is because I’m running silverblue or by design.

Is there a way for me to actually allow for the app to auto-update itself? Otherwise it’s going to say it has to update every single time or I have to manually check constantly for an update.

Here are my files. I’m open for any constructive criticism!

app-id: com.mmoui.Minion
runtime: org.freedesktop.Platform
runtime-version: '22.08'
command: minion.sh
sdk: org.freedesktop.Sdk
modules:
  - name: java8-runtime
    buildsystem: simple
    build-commands:
      - mkdir -p  /app/java/
      - cp -r jre /app/java/
    sources:
      - type: archive
        url: https://cdn.azul.com/zulu/bin/zulu8.66.0.15-ca-fx-jdk8.0.352-linux_x64.tar.gz
        sha256: 5e18c7fb108a14e5cba70354908d3ded7e7e741554fb7ddc5f8d9d297f8c9307
  - name: minion-client
    buildsystem: simple
    build-commands:
      - unzip Minion3.0.5-java.zip
      - mkdir -p                         /app/share/minion/lib
      - install -Dm755 -v lib/* -t       /app/share/minion/lib
      - install -Dm755 -v Minion-jfx.jar /app/share/minion
    sources:
      - type: file
        url: https://cdn.mmoui.com/minion/v3/Minion3.0.5-java.zip
        sha256: 0098613cce6e3b99decc45e6ecf6b71c4b8eed7fe0cd991611d6df5a7093bc1b
  - name: minion
    buildsystem: simple
    build-commands:
      - install -D minion.sh /app/bin/minion.sh
    sources:
      - type: file
        path: minion.sh
cleanup:
  - /app/share/minion
finish-args:
  - --env=PATH=/app/java/jre/bin:/usr/bin:/app/bin
  - --share=ipc
  - --socket=x11
  - --socket=wayland
  - --socket=fallback-x11
  - --share=network
  - --device=dri
  - --filesystem=host
  - --filesystem=~/.var/app/com.valvesoftware.Steam
#!/bin/bash

# Couldn't enable autoupdate, this way it at least doesn't make a file in working dir
cd /app/share/minion/

java -jar /app/share/minion/Minion-jfx.jar```

/app is read-only. There is no working around.