Switch WSGI gateway to Gunicorn and add TLS

[sjmf]

Deployment using the django debug server is bad practice. For deployment, we should serve the app via a uWSGI gateway like gunicorn. Further, it will be desirable to serve the app over https.

This will require the following changes to the Docker configuration:

• Add a webserver container (nginx)
• Include gunicorn in the python dependencies file (manyFEMS.env)
• Edit docker-compose for these containers
• Add træfik to handle SSL gateway tasks including requesting a Let'sEncrypt certificate via ACME

[sjmf]

This task is almost complete with commit 100621b. Production deployment can be achieved by pulling the repo and running the command:

docker-compose -f docker-compose.yml -f production.yml up -d

Almost.

This would be the case if there wasn't a port-binding conflict between traefik and nginx. Nginx is bound to port 80 in development. Need to test if changing this back to 8000 will also allow forwarding with traefik.

[sjmf]

81760399 reset the default port to 8000. To override this, create a file docker-compose.override.yml with the following contents:

version: '3.6'
services:
  web:
    ports:
      - "80:80/tcp

Then run:

docker-compose up -d

docker-compose.override.yml is in the .gitignore file as of commit 0a459d8. To perform a production deployment with SSL, simply create this file with the contents of production.yml, e.g.:

cp production.yml docker-compose.override.yml