paas-charm 1.4.1

Companion library for 12-factor app support in Charmcraft & Rockcraft.

PaaS Charm

Easily deploy and operate your Flask or Django applications and associated infrastructure, such as databases and ingress, using open source tooling. This lets you focus on creating applications for your users backed with the confidence that your operations are taken care of by world class tooling developed by Canonical, the creators of Ubuntu.

Have you ever created an application and then wanted to deploy it for your users only to either be forced to use a proprietary public cloud platform or manage the deployment and operations yourself? PaaS Charm will take your application and create an OCI image using Rockcraft and operations code using Charmcraft for you. The full suite of tools is open source so you can see exactly how it works and even contribute! After creating the app charm and image, you can then deploy your application into any Kubernetes cluster using Juju. Need a database? Using Juju you can deploy a range of popular open source databases, such as PostgreSQL or MySQL, and integrate them with your application with a few commands. Need an ingress to serve traffic? Use Juju to deploy and integrate a range of ingresses, such as Traefik, and expose your application to external traffic in seconds.

Getting Started

There are 2 requirements for the flask application:

• There is a requirements.txt file in the project root
• The WSGI path is app:app

Make sure that you have the latest/edge version of Charmcraft and Rockcraft installed:

sudo snap install charmcraft --channel latest/edge --classic
sudo snap install rockcraft --channel latest/edge --classic

Both have the flask-framework profile to create the required files and include the flask-framework extension which will do all the hard operational work for you and you just need to fill in some metadata in the rockcraft.yaml and charmcraft.yaml files. To create the necessary files:

rockcraft init --profile flask-framework
mkdir charm
cd charm
charmcraft init --profile flask-framework

After packing the rock and charm using rockcraft pack and charmcraft pack and uploading the rock to a k8s registry, you can juju deploy your flask application, integrate it with ingress and start serving traffic to your users!

Read the comprehensive getting started tutorial for more!

Additional resources:

• Tutorial to build a rock for a Flask application
• Charmcraft flask-framework reference
• Charmcraft flask-framework how to guides
• Rockcraftflask-framework reference

Contributing

Is there something missing from the 12-Factor app support framework? We welcome contributions! See CONTRIBUTING.md for more details.