Add GitHub Actions workflow for linux frontend

.github/workflows/main.yml

@@ -290,6 +290,66 @@ jobs:
         parallel: true
         flag-name: "flutter"
 
+  flutter-linux-release:
+    #needs: [flutter-analyze, flutter-format, flutter-test]
+    name: Relase frontend for Linux
+    runs-on: ubuntu-latest
+    env:
+      CMAKE_C_COMPILER_LAUNCHER: ""
+      CMAKE_CXX_COMPILER_LAUNCHER: ""
+    defaults:
+      run:
+        working-directory:
+          frontend
+    steps:
+    - uses: actions/checkout@v2
+      with:
+        submodules: recursive
+
+    - name: Install flutter
+      uses: subosito/flutter-action@v2
+      with:
+        flutter-version: ${{ env.FLUTTER_VERSION }}
+        channel: ${{ env.FLUTTER_CHANNEL }}
+        cache: true
+        cache-key: ${{ github.job }}
+
+    - name: Install flutter dependencies
+      run: |
+        sudo apt-get update -y
+        sudo apt-get install -y ninja-build libgtk-3-dev
+        flutter doctor -v
+
+    - name: Flutter pub cache
+      uses: actions/cache@v2
+      with:
+        path: ${{ env.PUB_CACHE }}
+        key: flutter-pub-${{ github.job }}-${{ hashFiles('**/pubspec.lock') }}
+        restore-keys: |
+          flutter-pub-${{ github.job }}-
+
+    - run: flutter pub get
+
+    - name: Generate code
+      run: flutter pub run build_runner build
+
+    - name: Build
+      run: flutter build linux
+
+    - name: Create AppImage
+      uses: docker://appimagecrafters/appimage-builder:1.1.0
+      with:
+        entrypoint: bash
+        args: "-c 'cd frontend; appimage-builder --recipe AppImageBuilder.yml --skip-test'"
+
+    - run: ls -la
+    - run: ls -la frontend
+
+    - uses: actions/upload-artifact@v3
+      with:
+        name: frontend-appimage
+        path: frontend/ShrapnelDSP-latest-x86_64.AppImage
+
   coveralls-finish:
     needs: [flutter-test, ctest]
     runs-on: ubuntu-latest

frontend/.gitignore

@@ -46,3 +46,8 @@ app.*.map.json
 /android/app/debug
 /android/app/profile
 /android/app/release
+
+# AppImage
+*.AppImage*
+AppDir
+appimage-build

frontend/AppImageBuilder.yml

@@ -0,0 +1,57 @@
+# appimage-builder recipe see https://appimage-builder.readthedocs.io for details
+version: 1
+script:
+  - rm -rf AppDir || true
+  - cp -r build/linux/x64/release/bundle AppDir
+  - mkdir -p AppDir/usr/share/icons
+  - cp web/icons/Icon-192.png AppDir/usr/share/icons
+AppDir:
+  path: ./AppDir
+  app_info:
+    id: com.example.app
+    name: ShrapnelDSP
+    icon: Icon-192
+    version: latest
+    exec: shrapnel
+    exec_args: $@
+  apt:
+    arch:
+    - amd64
+    allow_unauthenticated: true
+    sources:
+    - sourceline: deb http://archive.ubuntu.com/ubuntu/ jammy main restricted universe multiverse
+    - sourceline: deb http://archive.ubuntu.com/ubuntu/ jammy-updates main restricted universe multiverse
+    - sourceline: deb http://archive.ubuntu.com/ubuntu/ jammy-backports main restricted universe multiverse
+    - sourceline: deb http://security.ubuntu.com/ubuntu/ jammy-security main restricted universe multiverse
+    include:
+    - libgtk-3-0
+    - libwayland-client0
+    - libwayland-cursor0
+    - libwayland-egl1
+  files:
+    include: []
+    exclude:
+    - usr/share/man
+    - usr/share/doc/*/README.*
+    - usr/share/doc/*/changelog.*
+    - usr/share/doc/*/NEWS.*
+    - usr/share/doc/*/TODO.*
+  test:
+    fedora-30:
+      image: appimagecrafters/tests-env:fedora-30
+      command: ./AppRun
+    debian-stable:
+      image: appimagecrafters/tests-env:debian-stable
+      command: ./AppRun
+    archlinux-latest:
+      image: appimagecrafters/tests-env:archlinux-latest
+      command: ./AppRun
+    centos-7:
+      image: appimagecrafters/tests-env:centos-7
+      command: ./AppRun
+    ubuntu-xenial:
+      image: appimagecrafters/tests-env:ubuntu-xenial
+      command: ./AppRun
+AppImage:
+  arch: x86_64
+  update-information: guess