meta-flutter / workspace-automation

Work aids for developing with Embedded Flutter on Linux

Flutter Workspace Automation

Workspace Automation that supports embedded Flutter development

We developed a Python script, flutter_workspace.py to automate embedded flutter setup. This script reads a configuration folder of JSON files, or a single JSON configuration file and sets up a Flutter Workspace.

create_aot.py

create AOT is used to create libapp.so for use on a device.

Example use:

./create_aot --path <path that holds a pubspec.yaml>

Expects to be run from an active FLUTTER_WORKSPACE. Meaning you need to source you environment first.

create_recipes.py

creates a Yocto recipe for every pubspec.yaml found in a path folder. It will recursively iterate all subfolders.

Example use:

./create_recipes.py --path app/packages/ --license LICENSE --license_type BSD3-Clause --author "Google" --out ./tmp

Environmental variables used by script:

• GEN_SNAPSHOT - (Required) Set GEN_SNAPSHOT to location of executable gen_snapshot

• PUB_CACHE - Set using source ./setup_env.sh

• FLUTTER_WORKSPACE - Set using source ./setup_env.sh

• FLUTTER_BUILD_ARGS - Defaults to 'bundle'

• LOCAL_ENGINE_HOST - Defaults to f'{flutter_sdk}/bin/cache/artifacts/engine/common'

• APP_GEN_SNAPSHOT_FLAGS

• APP_GEN_SNAPSHOT_AOT_FILENAME - Defaults to 'libapp.so.{runtime_mode}'

• FLUTTER_PREBUILD_CMD

roll_meta_flutter.py

Updates all Flutter App recipes in meta-flutter using json as data source. The default data source is configs/flutter-apps.json

Example use

./roll_meta_flutter.py --path `pwd`/tmp

Default pubspec.yaml filter tokens

_android/pubspec.yaml
_ios/pubspec.yaml
_linux/pubspec.yaml
_macos/pubspec.yaml
_platform_interface/pubspec.yaml
_web/pubspec.yaml
_windows/pubspec.yaml

Default recipe filename filter tokens

-apple_
-avfoundation_
-darwin_
-linux_
-web_

Note: Exclude filters are added to json as "exclude" string array. The value to populate exclude filter is the FLUTTER_APPLICATION_PATH value. An empty string is valid.

flutter_workspace.py

flutter_workspace.py does the following tasks automatically for you

• Establishes a workspace of known state
• Sync repos into app folder
• .vscode debug launcher file
• Flutter SDK
• Flutter runtime=debug engine
• Loads platform types
  • QEMU, Docker, Remote, Host, Generic
  • Each type uses a specific configuration
• Create setup_env.sh
• Tested on Linux and Mac
  • Ubuntu 20 (x86_64)
  • Ubuntu 22 (x86_64)
  • Fedora 37 (x86_64)
  • Mac M1/M2 (arm64)

Flutter Workspace

A Flutter workspace contains

• Flutter SDK
  • flutter
• Development Repositories (app)
  • app
• Host Runtime images
  • .config/flutter_workspace/
• flutter-auto binary
  • app/ivi-homescreen/build
• QEMU image
  • .config/flutter_workspace//)
• Versioned x86_64 libflutter_engine.so and icudtl.dat
  • ./config/flutter_workspace/flutter-engine
• Custom-device configurations
  • ./config/flutter_workspace/
• Public Cache
  • .config/flutter_workspace/pub_cache

JSON Configuration

flutter_workspace_config.json contains the following components

• globals
  • cookie_file
  • netrc
  • github_api
• repos
  • git
• platform definition

Installation

git clone https://github.com/meta-flutter/workspace_automation.git
./flutter_workspace.py

Options

--clean

Wipes workspace before creating

--config=

Pass configuration JSON file, or folder path.

--flutter-version=x.x.x

Override config/_globals.json key "flutter_version"

--fetch-engine

Fetch libflutter_engine.so and update bundle cache

--version-files=

Pass folder for storing dart and engine json files.

--plex="..."

Platform Load Exceptions. Pass platform-id values. Space is delimiter

--stdin-file

Use for debugging

Run flutter app with desktop-auto

• Login via GDM Wayland Session
• Open Terminal and type
• source ${FLUTTER_WORKSPACE}/setup_env.sh
• Navigate to your favorite app
• flutter run -d desktop-auto

Run flutter app with QEMU

• Open Terminal and type
• source ${FLUTTER_WORKSPACE}/setup_env.sh
• Type qemu_run
• Wait until QEMU image reaches login prompt
• Run ssh –p 2222 root@localhost who to add remote host to ~/.ssh/known_hosts
• Navigate to your favorite app
• flutter run -run-qemu-master

Create hello_world flutter example

• Login to Ubuntu desktop via Wayland Session
• Open Terminal and type
• source ${FLUTTER_WORKSPACE}/setup_env.sh
• cd ${FLUTTER_WORKSPACE}/app
• flutter create hello_world -t app
• cd hello_world
• flutter run -d desktop-auto

Visual Studio Code

Launching on Ubuntu

    cd <your flutter workspace>
    source ./setup_env.sh
    code .

Debugging with VS Code

flutter_workspace.py creates a .vscode/launch.json file if one is not present. It uses the repo json key pubspec_path. If this key is present in the repo json, then it will add entry to .vscode/launch.json.