charmcraft

Charmcraft -- easily initialise, pack, and publish your charms

Charmcraft is a CLI tool that makes it easy and quick to initialise, package, and publish Kubernetes and machine charms. It is an official component of the Charm SDK, itself a part of the Juju universe.

	Juju	Learn how to quickly deploy, integrate, and manage charms on any cloud with Juju. It's as simple as juju deploy foo, juju integrate foo bar, ..., on any cloud.
	Charmhub	Sample our existing charms on Charmhub. A charm can be a cluster (OpenStack, Kubernetes), a data platform (PostgreSQL, MongoDB, etc.), an observability stack (Canonical Observability Stack), an MLOps solution (Kubeflow), and so much more.
:point_right:	Charm SDK	Write your own charm! Juju is written in Go, but our SDK supports easy charm development in Python.

Give it a try

Let's use Charmcraft to initialise and pack a Kubernetes charm:

Set up

See Charm SDK | Set up your development environment automatically > Set up an Ubuntu charm-dev VM with Multipass.
Choose the MicroK8s track.

Initialise and pack your charm

In your Multipass VM shell, create a charm directory and use Charmcraft to initialise your charm file structure:

mkdir my-new-charm
cd my-new-charm
charmcraft init

This has created a standard charm directory structure:

$ ls -R
.:
CONTRIBUTING.md  README.md        pyproject.toml    src    tox.ini
LICENSE          charmcraft.yaml  requirements.txt  tests

./src:
charm.py

./tests:
integration  unit

./tests/integration:
test_charm.py

./tests/unit:
test_charm.py

Poke around:

Note that the charmcraft.yaml file shows that what we have is an example charm called my-new-charm, which builds on Ubuntu 22.04 and which uses an OCI image resource httpbin from kennethreitz/httpbin.

Note that the src/charm.py file contains code scaffolding featuring the Charm SDK's Ops library for writing charms.

Explore further, start editing the files, or skip ahead and pack the charm:

charmcraft pack

If you didn't take any wrong turn or simply left the charm exactly as it was, this should work and yield a file called my-new-charm_ubuntu-22.04-amd64.charm (the architecture bit may be different depending on your system's architecture). Use this name and the resource from the metadata.yaml to deploy your example charm to your local MicroK8s cloud with Juju:

juju deploy ./my-new-charm_ubuntu-22.04-amd64.charm --resource httpbin-image=kennethreitz/httpbin

Congratulations, you’ve just initialised and packed your first Kubernetes charm using Charmcraft!

But Charmcraft goes far beyond init and pack. For example, when you're ready to share your charm with the world, you can use Charmcraft to publish your charm on Charmhub. Run charmcraft help to preview more.

Clean up

See Charm SDK | Set up your development environment automatically > Clean up.

Next steps

Learn more

Read our user documentation, which also includes other guides showing Charmcraft in action

Chat with us

Read our Code of conduct and:

• Join our chat: Matrix
• Join our forum: Discourse

File an issue

• Report a Charmcraft bug on GitHub
• Raise a general https://juju.is/docs documentation issue on GitHub | juju/docs

Make your mark

• Read our documentation contributor guidelines and help improve a doc
• Read our codebase contributor guidelines and help improve the codebase