First working draft docker-compose

[MartenBE]

This branch is based on the work already delivered by @hat .

TODO's

• Make sure the application can handle it if the DB isn't ready or found (other solution is wait-for-it in docker, but it is better to solve the generic case). Partially solved as docker-compose supports depends, but the error still happens sometimes. Restarting docker -compose (docker -compose down and docker-compose up) manually a second time does fix the problem.
• Remove everything involved with the installer. Solved.
• Instead of pulling nginx in ourselves, use the uwsgi to connect to an external nginx container via docker-compose. This allows us to swith from ubuntu as base image to the python base image which has everything we need already included. This way we don't need to apt update/install anything ourselves.
• Deduplicate options in both .env and config.json, or allow mounting the config.json file. This is especially important for the database variables (POSTGRES_DB, POSTGRES_USER, POSTGRES_PASSWORD).
• Move the docker stuff into a docker subfolder. Solved: use docker-compose -f ./docker/development.docker-compose.yml up --build in the project root to start both pyshelf and the database.
• Figure out how to make this work with dockerhub. Also figure out how to generate the image automatically after each release using CI. Solved: use the following commands in the project root to build and push the docker image to dockerhub:

  docker build -t pyshelf/pyshelf -f .\docker\Dockerfile .
  docker login
  docker push pyshelf/pyshelf
  

  The integration of this command with github CI should be done in a way which is most comfortable for @th3r00t . Perhaps https://docs.github.com/en/actions/language-and-framework-guides/publishing-docker-images is a solution?

The docker-compose here should only be given as an example. pyShelf should only be responsible for a pyShelf image on dockerhub. The docker-compose is normally written by the user himself, so he can decide which folder to use, which webserver, which database, etc. ... . Therefor, we should keep this as simple and generic as possible.

Example of the docker-compose.yml file:

version: "3.8"

services:
    db:
        image: "postgres"
        environment:
            - "POSTGRES_PASSWORD=pyshelf"
            - "POSTGRES_USER=pyshelf"
            - "POSTGRES_DB=pyshelf"
        volumes:
            - "db_data:/var/lib/postgresql/data/"

    pyshelf:
        image: "pyshelf/pyshelf"
        ports: 
            - "8080:8000"
        volumes:
            - "${LOCAL_BOOK_DIR}:/books"
        depends_on:
            - db

volumes:
    db_data:

Example of the .env file:

LOCAL_BOOK_DIR=/home/someone/books