Role uv

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Summary

uv is an extremely fast Python version, package and project manager, written in Rust. This role:

1. Installs uv (if it is not already present).
2. Installs desired versions of python with uv.
3. Creates virtual envs with specified python versions.

Note that the SRC-External component, which is executed on most if not all workspaces, already installs uv (as of February 2025). Actual installation of uv is therefore skipped by this role to save time, unless a special variable is toggled (see below).

Requires

• Debian-based system

Description

This role will install uv using pipx, to the default location defined by the pipx role. A link to the uv binary installed by pipx is placed in /usr/local/bin/, so uv is on the PATH for each user.

Aditionally, a script /usr/local/bin/uv_pip is installed, which is essentially an alias for uv pip. This is for convenience of use in Ansible playbook: it e.g. allows passing uv_pip as the executable for a call to Ansible’s pip module.

The role also supports creating venvs and installing desired Python versions (see below).

The role will set a fact uv_python_paths, which contains a dict containing the location of the python interpreter for each requested versions. For example:

uv_python_paths: {
    '3.11': '/root/.local/share/uv/cpython-xxxxx/bin/python3'
}

Variables

• uv_vens: List of dicts describing virtual environments to be initialized with uv. Each item in the dict is expected to contain a path attribute: specifying the location of the venv. You can also specify the python attribute to install a specific python version and use it with the venv. If you want to default to the system python, don’t set the python attribute, and instead set the python_preference attribute to 'system' (see uv venv’s --python-preference option.) Examples: { path: '/tmp/foo', python: '3.11' }, or { path: '/tmp/foo', python_preference: 'system' }.
• uv_python_versions: List of strings of python versions to be installed with uv. For example: [ '3.11', '3.12.3' ].
• uv_become: Boolean. Whether to excute UV tasks (installation of Python versions and creation of venvs) as a different (non-root) user. Default: false.
• uv_become_user: String. If uv_become is set to true, which user should the tasks be executed as? E.g. www-data. Default: root.
• uv_force_install: Boolean. By default it is assumed that uv is already present on the system. Setting this variable to true will force-install it. Default: false.

See also

• pipx_install_systemwide role

History

2024-2025 Written by Dawa Ometto (Utrecht University)

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