Package Flutter Linux App Into AppImage Part 2

Now, We are ready to build our first Flutter AppImage app 🚀

Firstly , we will change our working directory to the project directory.

$ cd flutter_appimage

Then follow these steps:

1- Create folder AppDir

$ mkdir AppDir

2- Generate the YAML recipe file required to build the AppImage

$ appimage-builder --generate

this command will prompt some questions. Here is the final output :

INFO:Generator:Searching AppDir
? ID [Eg: com.example.app]: com.example.flutter_appimage
? Application Name: Flutter AppImage
? Icon: flutter_appimage_icon
? Executable path relative to AppDir [usr/bin/app]: flutter_appimage
? Arguments [Default: $@]: $@
? Version [Eg: 1.0.0]: latest
? Update Information [Default: guess]: guess
? Architecture: x86_64

Now, you will notice a new file AppImageBuilder.yml added to the root directory of our project.

Wait a second, What the hack this flutter_appimage_icon comes from 🙄🤔

Stop rubbing your head. Here is why :

copy your favorite icon to the root directory and make sure its extension is SVG
rename you icon to flutter_appimage_icon.svg

Now, let's open `AppImageBuilder.yml` and edit some stuff:

add starting script that will delete old AppDir:

script:
   - rm -rf AppDir | true
   - mkdir AppDir

add after bundling scripts to add the Flutter App to the bandle

AppDir:
    after_bundle:
    - cp build/linux/x64/release/bundle/flutter_appimage AppDir
    - cp -r build/linux/x64/release/bundle/lib/. AppDir/lib
    - cp -r build/linux/x64/release/bundle/data AppDir
    - cp flutter_appimage_icon.svg AppDir/usr/share/icons/

Add gtk3 required for flutter app also define the repositories where dependencies comes from

pacman:
      Architecture: x86_64
      repositories:
        core:
          - https://mirror.rackspace.com/archlinux/$repo/os/$arch
        extra:
          - https://mirror.rackspace.com/archlinux/$repo/os/$arch
      include:
        - gtk3
        - python # I don't know why we need but build fails without it  
        - perl # I don't know why we need but build fails without it