Arduino App CLI

arduino-app-cli is a command line tool and a service running on Arduino UNO Q boards, that:

• manages and runs Arduino Apps on the board (both Linux and microcontroller parts)
• provides multiple APIs to perform actions and fetch data, used by the front-end (ArduinoAppsLab)
• auto-updates itself and other components

Environment Variables

The following environment variables are used to configure arduino-app-cli:

Application Directories

• ARDUINO_APP_CLI__APPS_DIR Path to the directory where Arduino Apps created by the user are stored.
  Default: /home/arduino/ArduinoApps

• ARDUINO_APP_CLI__DATA_DIR Path to the directory where internal data is stored.
  Default: /home/arduino/.local/share/arduino-app-cli
  This folder contains:

  • examples/ default example Apps (e.g. /home/arduino/.local/share/arduino-app-cli/examples)
  • assets/ contains a subfolder for each asset version (e.g. /home/arduino/.local/share/arduino-app-cli/assets/0.4.5)
    • Each asset folder includes:
      • bricks-list.yaml
      • models-list.yaml
  • other data such as properties.msgpack containing variable values

• ARDUINO_APP_BRICKS__CUSTOM_MODEL_DIR Path to the directory where custom models are stored.
  Default: $HOME/.arduino-bricks/ei-models
  (e.g. /home/arduino/.arduino-bricks/ei-models)

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Execution Settings

• ARDUINO_APP_CLI__ALLOW_ROOT Allow running arduino-app-cli as root.
  Default: false Not recommended to set to true.

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External Services

• LIBRARIES_API_URL URL of the external service used to search libraries.
  Default: https://api2.arduino.cc/libraries/v1/libraries

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Docker Settings

• DOCKER_REGISTRY_BASE Docker registry used to pull images.
  Default: ghcr.io/arduino/

• DOCKER_PYTHON_BASE_IMAGE Tag of the Docker image for the Python runner.
  Default: app-bricks/python-apps-base:<RUNNER_VERSION>

App folder and persistent data

When running an app, persistent files will be saved in the data folder inside the app folder; other supporting files, including the Python venv are saved in the .cache folder inside the app folder.

Docker images registry

Arduino Apps bricks might required a docker image, in that case the orchestrator will pull those from the registry configured with the DOCKER_REGISTRY_BASE environment variable. By default this points to an Arduino GitHub Container Registry (ghcr.io/arduino).

The only image that needs to be referenced directly is the base Python image (DOCKER_PYTHON_BASE_IMAGE), all other containers can be downloaded automatically by the orchestrator depending on the bricks specified as dependencies in the app.yml file.