tox.ini file

The tox.ini file in your charm’s root directory is a typical tox configuration file.

Charmcraft creates this file and defines the following tox environments:

Environment

Purpose

format

Apply coding style standards

lint

Check code against coding style standards and static checks

unit

Run the charm’s unit tests

integration

Run the charm’s integration tests

To run the commands in an environment, use tox -e <env-name>.

For the Kubernetes and machine profiles, tox.ini requires the tox-uv plugin. First make sure that uv is installed on the current host. Then use uv to install tox and tox-uv:

uv tool install tox --with tox-uv

Configuration of testing and linting tools is specified in the pyproject.toml file. Dependencies are also specified in pyproject.toml. If you manually modify the dependencies in pyproject.toml, you’ll need to update the uv.lock file before using tox.

For 12-factor app profiles, tox.ini doesn’t require any plugins. Dependencies are specified in the requirements.txt file instead of pyproject.toml.