markshuttle / charmcraft

The Charm Tool

What is charmcraft?

Charmcraft provides a streamlined, powerful, opinionated, and flexible tool to develop, package, and manage the lifecycle of Juju charm publication, focused particularly on charms written within the Operator Framework.

It is still in heavy, initial development and so a lot is still To Be Done. However it is already useful, and already simplifies the life of the charmer.

How do I install it?

The easiest way to install charmcraft is by doing

sudo snap install --beta charmcraft

(more options are available as per snap info charmcraft) but some people with more esoteric needs not covered by the snap might need to instead go via pip3 install --user charmcraft.

What can it do for me today?

It can build your charm! No need for git submodules nor pesky hook symlinks, you can concentrate on your charm being pure python code (plus the required juju metadata), and charmcraft will fill in the boring bits for you.

For example, given a charm that consists exclusively of

my-charm
├── metadata.yaml
├── requirements.txt
└── src/
    └── charm.py

(and assuming ops is in requirements.txt), then running charmcraft build will produce a charm that looks like

my-charm
├── dispatch
├── hooks
│   ├── install -> ../dispatch
│   ├── start -> ../dispatch
│   └── upgrade-charm -> ../dispatch
├── metadata.yaml
├── src/
│   └── charm.py
└── venv/
    ├── ops/
    │   ├── ...
    └── yaml/
        └── ...

which should be all you need to juju deploy the charm!

How do I run it from source?

git clone https://github.com/canonical/charmcraft.git
cd charmcraft
virtualenv venv
. venv/bin/activate
pip install -r requirements.txt
python -m charmcraft

If you would like to run the tests you can do so with

pip install -r requirements-dev.txt
./run_tests