flatpak-gradle-generator

A Gradle plugin to generate a sources file for offline Flatpak builds.

The plugin will output all direct and transitive dependencies for all build configurations (including plugin dependencies) in a JSON file. The JSON file can be used in a Flatpak build process to download Maven dependencies before an offline build starts. The downloaded files will be stored in a local Maven repository layout.

Example gradle.build:

plugins {
  id 'application'
  id 'io.github.jwharm.flatpak-gradle-generator' version '1.1.0'
}

repositories {
  mavenCentral()
  maven { url './offline-repository' }
}

dependencies {
  // a random dependency for this example
  implementation 'io.github.jwharm.javagi:adw:0.7.1'
}

tasks.flatpakGradleGenerator {
  outputFile = file('flatpak-sources.json')
  downloadDirectory = './offline-repository'
}

Run gradle flatpakGradleGenerator and it will write a json file with information about the dependencies:

[
  {
    "type": "file",
    "url": "https://repo.maven.apache.org/maven2/io/github/jwharm/javagi/adw/0.7.1/adw-0.7.1.module",
    "sha512": "d265d970864b3fb4c97b0fe87030ba76eafb252531d9da37cd7a51296b32e95bb70154f0075f6a0d0bc1e41fbd7f23280bdc6b317a1d5808c5a0c4b3a5ac70b5",
    "dest": "./offline-repository/io/github/jwharm/javagi/adw/0.7.1",
    "dest-filename": "adw-0.7.1.module"
  },
  {
    "type": "file",
    "url": "https://repo.maven.apache.org/maven2/io/github/jwharm/javagi/adw/0.7.1/adw-0.7.1.jar",
    "sha512": "356a1c8f8ae89d7212bdfccd9afcd607ae86301485dd850d11eb378cbfe6f05f00cee27be368f907b0b941a065564f7ca3fb7ee18b21f4aaf8bec4d4176ba65a",
    "dest": "./offline-repository/io/github/jwharm/javagi/adw/0.7.1",
    "dest-filename": "adw-0.7.1.jar"
  },
  ...etc...

Add the JSON filename to the sources list in your Flatpak manifest, and flatpak-builder will automatically download all dependencies into the offline Maven repository folder.

Modular builds

Because a task from one Gradle project is not allowed to directly resolve a configuration in another project, the plugin is limited to the project context in which the flatpakGradleGenerator task is declared.

In a modular Gradle build, you can add a tasks.flatpakGradleGenerator {} block in the build files of the subprojects, to generate separate files for each project.

Requirements

The plugin has been tested with Gradle 8.3, 8.4, 8.6 and 8.7. The published jar is built with Java 17.