giosal / epfl_sti_devops_challenge

EPFL STI DevOps Challenge

EPFL STI DevOps Challenge v 0.40

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As requested per the challenge task (found here https://github.com/jaepetto/STI-devops-challenge), this repository includes 4 main components

• Django web container, running Gunicorn server, based on https://github.com/realpython/dockerizing-django
• 2 Nginx reverse proxy contianers
• PostgreSQL DB container
• HaProxy Load Balancer container

1. Prerequisites docker
docker-compose
snap
   

2. Setup In order to run initial setup on Ubuntu, either run
   ./setup.sh
   or
   sudo snap install docker
   

3. Build In order to build the container, run docker-compose up -d --build
   

4. Prepare Django You also need to migrate Django DBs to PostgreSQL DB. For that, run:
   nano epflchallenge/apps/todo/migrations/__init__.py
   then (based on previous experience, running migrations outside of container's bash may not complete successfully)
   docker run -ti epfl_challenge_web_1 bash
   then
   mkdir epflchallenge/apps/todo/migrations
   then
   python manage.py makemigrations
   and finally
   python manage.py migrate
   

5. Find the IP
   docker inspect web
   

6. Go to the IP and see the page
   

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Several important comments:

1. The application uses .env file to store environment variables, such as PostgreSQL host, user and password, for use in Django settings.py
2. HaProxy uses a script to open the ports
3. Failover can be increased by simply adding additional Nginx node in docker_compose.yml and haproxy.cfg
4. HaProxy and Nginx can be configured to accept connections over HTTPS, which is important in this day and age.
5. In order to update containers without downtime, it's enough to run docker-compose up -d --build