flatpak_demo

README

flatpak_demo

A demo of a Fyne application packaged as a Flatpak. This project is intended to serve as a starting point to help developers package their Fyne applications using Flatpak.

Requirements

Both flatpak and flatpak-builder need to be installed in order to build the packages. Commands for installing Flatpak can be found here. Installing the builder should be very similar. More information about how to build Flatpaks can be found here and here.

With that installed, we need to first get the flathub repository set up.

flatpak remote-add --if-not-exists flathub https://flathub.org/repo/flathub.flatpakrepo

We can now move on to installing the development SDKs that we are going to use:

flatpak install flathub org.freedesktop.Platform//23.08 org.freedesktop.Sdk//23.08 org.freedesktop.Sdk.Extension.golang//23.08

Building and installing

Building the package can be done with the following command:

flatpak-builder --user --force-clean build-dir io.fyne.flatpak_demo.yml

The package can also be built and installed in one step, using the following command:

flatpak-builder --user --install --force-clean build-dir io.fyne.flatpak_demo.yml

Running

The installed package can then be started by running the following command:

flatpak run --user io.fyne.flatpak_demo

Vendoring

It is possible to enable network access during the build, but it is recommended to not do so. If you want to publish the package to flathub, it is even a requirement. For that reason, it is a good idea to vendor the project using go mod vendor and add the files to the git repo.

Sandbox permissions

The Flatpak applications run within a sandbox that restricts their communication with the host system. It is generally preferred to have the application be as strict as possible, with no more permissions enabled than necessary. Our example app only opens up filesystem access for the Documents folder as well as the Fyne config directory to support Fyne preferences and Fyne document storage system. Remove these if your app do not need it. More information on avaliable permissions can be found on the sandbox-permissions and the sandbox-permissions-reference documentation pages.

Appdata and desktop files

Flatpak requires the application to provide metadata about itself. This data is then used in application stores like Gnome Software, KDE Discover and many others, to display information about the application. This metadata can easily be created using the AppStream Metainfo Creator, or you can use the io.fyne.flatpak_demo.appdata.xml file as a reference.

A desktop file (.desktop) is also required (as with any other Linux desktop application). You can let the metainfo creator above generate one for you, or you can use the io.fyne.flatpak_demo.desktop file as a reference.

Example manifest

The manifest for this project can be found below. It can be used as a base to use when packaging other apps using Flatpak. The sha256 field for the source can be found by downloading the file and running sha256sum on it.

Please note that this manifest file normally wouldn't be in the same repository as the rest of the code, but instead part of a separate flatpak-specific repository. We have it in the same repository here for the sake of simplicity. This manifest uses the latest release of this repository and will not get local changes.

app-id: io.fyne.flatpak_demo
runtime: org.freedesktop.Platform
runtime-version: '22.08'
sdk: org.freedesktop.Sdk
sdk-extensions:
    - org.freedesktop.Sdk.Extension.golang
command: flatpak_demo

finish-args:
    - --share=ipc # Share IPC namespace with the host (necessary for X11).
    - --socket=x11
    - --device=dri # OpenGL rendering support.

    # Only needed if building with -tags wayland.
    #- --socket=wayland

    # Needed to support desktop notifications.
    - --talk-name=org.freedesktop.Notifications

    # Allowing access to the home directory as example.
    - --filesystem=home

build-options:
  env:
    - GOBIN=/app/bin
    - GOROOT=/usr/lib/sdk/golang

modules:
    - name: flatpak_demo
      buildsystem: simple
      build-commands:
        - $GOROOT/bin/go build -trimpath -o flatpak_demo
        - install -Dm00755 flatpak_demo $FLATPAK_DEST/bin/flatpak_demo
        - install -Dm00644 Icon.png $FLATPAK_DEST/share/icons/hicolor/256x256/apps/$FLATPAK_ID.png
        - install -Dm00644 $FLATPAK_ID.desktop $FLATPAK_DEST/share/applications/$FLATPAK_ID.desktop
        - install -Dm00644 $FLATPAK_ID.appdata.xml $FLATPAK_DEST/share/appdata/$FLATPAK_ID.appdata.xml
      sources:
        - type: archive
          url: "https://github.com/fyne-io/flatpak_demo/archive/refs/tags/v1.2.0.tar.gz"
          sha256: bd892edacf56af9d443fd7f9f4825a33165a46d4d7bb56aee3de690144798c18

Building local code

If you want to build using the local code in the repository instead of the latest release, you can swap out the source section in the manifest above with this:

      sources:
        - type: dir
          path: ./

Screenshots