From zero to hero: Write your first Kubernetes charm

This tutorial will introduce you to the official way to write a Kubernetes charm — that is, how to equip an application with all the operational logic that it needs so that you can manage it on any Kubernetes cloud with just a few commands, using Juju.

What you’ll need:

• A working station, e.g., a laptop with amd64 architecture.
• Familiarity with Juju
• Familiarity with the Python programming language, Object-Oriented Programming, Event Handlers
• Understanding of Kubernetes fundamentals

What you’ll do:

• Study your application
• Set up your development environment
• Develop your charm:
  1. Create a minimal Kubernetes charm
  2. Make your charm configurable
  3. Expose the version of the application behind your charm
  4. Integrate your charm with PostgreSQL
  5. Preserve your charm’s data
  6. Expose your charm’s operational tasks via actions
  7. Observe your charm with COS Lite and set up cross-model integrations
  8. Write unit tests for your charm
  9. Write scenario tests for your charm
  10. Write integration tests for your charm
  11. Open a Kubernetes port in your charm
  12. Publish your charm on Charmhub

Next steps:

By the end of this tutorial you will have built a Kubernetes charm and evolved it in a number of typical ways. But there is a lot more to explore:

Contributors: @beliaev-maksim