AAS

A webhook listener for use at Study Association Sticky, written as a Flask application.

Its current use is to make automatic deployment possible of our website in our production environment, triggered by GitHub pushes or changes in the Contentful CMS it uses.

Usage

This project requires Python 3.7+ and [Nix][nix].

Development

$ # Use the provided sample.env to create a .env file and populate the environment variables
$ cp sample.env .env
$ vim .env
$ # Open a shell with Aas' development dependencies available
$ nix-shell
$ # Run the development server
$ python aas.py

The version of the Python dependencies is determined by the snapshot of the Nixpkgs package set. To update it to a newer snapshot, execute niv update inside the nix-shell and re-open the shell.

Production

The dependencies include gunicorn, which is a WSGI server for use in production. You can use the following commands as a simple example:

$ nix-shell default.nix --run "gunicorn aas:aas"

This binds gunicorn to http://localhost:8000/. You should place a reverse proxy, like nginx, in front of this.

Alternatively, to not need to invoke nix when the server is to be started, you can create a "virtualenv" containing only the production dependencies with:

$ nix-build -o aas-env

The server can then be started by running aas-env/bin/gunicorn aas:aas.

To set this up in our own production environment, we use some Ansible tasks.

Testing consumption of webhooks in development

To make the development server temporarily available for webhook consumers in the outside world (e.g. GitHub), you can use ngrok. ngrok is automatically made available when you run nix-shell.

To use it, you can run aas in one terminal and in another terminal run ngrok http 5000 (5000 being the default port Flask's development server binds to).