This document has a few tips for working on the vula codebase.

Vula is typically run as three daemons: organize, publish, and discover. The latter two perform the ZeroConf/mDNS functions, and organize communicates with them via d-bus and does everything else.

It is also possible to run organize in monolithic mode, meaning that all three daemons’ functions are performed in a single process, by running sudo vula organize run --monolithic. root is required to be able to configure the system; when running under systemd the CAP_NET_ADMIN capability allows us to do this without being root.

The top-level vula command has a hidden -d/--debug option which will drop you in to a pdb shell when there is an exception instead of exiting. When working on vula, it is helpful to systemctl stop vula-organize and then run sudo vula -vd organize to run the organize daemon in verbose and debugging mode. The state file will retain the ownership of the /var/lib/vula-organize directory, so there should be no conflict keeping state between invocations as root and as the vula-organize user which is used when running under systemd.

Setup development environment

For developing on your host system, you may find it helpful to set up an environment such as this:

export PIPENV_VERBOSITY=-1
python3 -m pip install --user pipx
python3 -m pipx ensurepath
pipx install pipenv
pipenv install black flake8 isort mypy pytest pytest-cov --dev --skip-lock

Alternately, you can use our multipass-tests scripts to easily run vula on a network of virtual machines.

Use common tools to inspect and interact with the vula codebase

Code (re)formatting with black

pipenv run black vula

Typing hints

Note: haven’t actually used mypy in a long time, but might return to it in the future.

pipenv run mypy

Linting with flake8

Note: we are long overdue for running this.

pipenv run flake8 vula

pytest

Our test suite runs with pytest. Coverage can be computed with pytest --cov --cov-fail-under=100 but we haven’t done that recently.