This repo contains tools for maintaining the kubernetes and machine profiles of Charmcraft. The tools are primarily intended to be used by the Charm Tech team at Canonical.

In the Charmcraft source, profiles are stored as .j2 template files. For example, charm.py.j2. This enables charmcraft init to fill in the charm name and other details, but testing the profiles can be awkward.

In this README

• Generate charms for testing
  • Integration tests
  • kubernetes-extra
• Update the uv.lock templates

Generate charms for testing

You'll need:

• The Charmcraft source. We'll assume this is located at ~/charmcraft.
• A virtual environment in the Charmcraft source. To create one, run make setup in the Charmcraft source.
• just, uv, and tox. To install tox, run uv tool install tox --with tox-uv.

After editing .j2 files in the Charmcraft source, run the following command in this repo:

CHARMCRAFT_DIR=~/charmcraft just init

This initializes a Kubernetes charm in the kubernetes directory and a machine charm in the machine directory. If you only want one of the charms, use just kubernetes or just machine instead of just init.

You can test the charms as normal using tox. Alternatively, initialize the charms and immediately test them:

CHARMCRAFT_DIR=~/charmcraft just init lint,unit

The list of environments after just init is passed to tox -e <environments> for each charm. This also works with just kubernetes and just machine.

Integration tests

Integration tests require a Juju controller. You can use Concierge to bootstrap a Juju controller.

Important

Don't run integration tests using just ... integration. Instead, in each directory, run charmcraft pack followed by tox -e integration.

The machine charm's integration tests should pass. The charm goes active without installing a workload.

The Kubernetes charm's integration tests should fail because Juju tries to deploy the charm alongside a placeholder container image.

kubernetes-extra

To generate a Kubernetes charm that passes integration tests, make sure you've initialized a Kubernetes charm (as above), then run:

just kubernetes-extra

This copies kubernetes to a directory called kubernetes-extra, then replaces the placeholder parts of the charm by real configuration/code. For details, see .implement/kubernetes-extra.py.

To generate the charm and immediately test it:

just kubernetes-extra lint,unit

To run the charm's integration tests:

cd kubernetes-extra
charmcraft pack
tox -e integration

Update the uv.lock templates

If you change the dependencies of the Charmcraft profiles, you'll need to update uv.lock.j2 for each profile.

Make sure you've initialized a Kubernetes charm and a machine charm (see Generate charms for testing). Then run just lock. This locks the dependencies of each charm and generates template files:

• .templates/init-kubernetes/uv.lock.j2
• .templates/init-machine/uv.lock.j2

You can copy these files to the Charmcraft source.

If you only want one of the files, use just lock-kubernetes or just lock-machine instead of just lock.