This repo has been created while following this tutorial by Sanjeev Thiyagarajan.

The objective of the repo is to create a twitter-like social media application backend.

The backend has been built on the following web technologies:

• API Framework: FastAPI
• Database: PostgreSQL
• ORM: SQLAlchemy
• Database Adapter: Psycopg
• Database Migration Tool: Alembic
• Web Server: Uvicorn and Gunicorn

The simpler way is to create a .env file in the home directory and utilize that. However, we usually want to avoid this approach since the file can accidentally be uploaded to the repo. Alternatively:

• Place the .env file in the home folder /home/ubuntu/
• Edit the .profile file in the home folder with the following command so that it triggers automatically when the system is started:

set -o allexport; source /home/ubuntu/.env; set +o allexport

• Run:

alembic upgrade head

• Run:

uvicorn --host 0.0.0.0 app.main:app

• Test by going to {Public IP}:8000 and {Public IP}:8000/docs

• Run:

gunicorn -w 4 -k uvicorn.workers.UvicornWorker app.main:app --bind 0.0.0.0:8000

• Test by going to {Public IP}:8000 and {Public IP}:8000/docs

• The output to the command should show 4 workers with 1 parent process

• Get python path by executing which gunicorn

• Go to /etc/systemd/system

• Create a new file called api.service with the following:

[Unit]
Description=FastAPI server service
After=network.target

[Service]
User=ubuntu
Group=ubuntu # same as User
WorkingDirectory=/home/ubuntu/src # whatever is the location of your application folder
Environment="PATH=/home/ubuntu/bin" # the bin location you got from which gunicorn
EnvironmentFile=/home/ubuntu/.env # the location to the .env file
ExecStart=/home/ubuntu/bin/gunicorn -w 4 -k uvicorn.workers.UvicornWorker app.main:app --bind 0.0.0.0:8000 # use the location you got from which gunicorn

[Install]
WantedBy=multi-user.target

• Note: the .profile edit to automatically import environment variables is no longer required

• Run: sudo systemctl start api

• Verify it is running with sudo systemctl status api

• Test by going to {Public IP}:8000 and {Public IP}:8000/docs

• Run: sudo systemctl enable api to force the service to restart on reboot

• Install nginx: sudo apt install nginx -y

• Start nginx: sudo systemctl start nginx

• Test by going to {Public IP} and it should show you an nginx welcome page

• Go to /etc/nginx/sites-available and open default

• Change the location block:

location / {
    proxy_pass http://localhost:8000;
    proxy_http_version 1.1;
    proxy_set_header X-Real-IP $remote_addr;
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
    proxy_set_header Upgrade $http_upgrade;
    proxy_set_header Connection 'upgrade';
    proxy_set_header Host $http_host;
    proxy_set_header X-NginX-Proxy true;
    proxy_redirect off;
}

• Run sudo systemctl restart nginx

• Test by going to {Public IP} and {Public IP}/docs and it should show you the API interface

• This requires you to have a domain name attached to the {Public IP}

• As an example, attach both api.com and www.api.com to the {Public IP} through DNS records

• Test by going to api.com and api.com/docs

• Test by going to www.api.com and www.api.com/docs

• Go to Certbot instructions page

• Select nginx and Ubuntu 20

• Follow the guide to setup the certificate

• Make sure port 443 is open for HTTPS requests

• Test by going to api.com and api.com/docs; the connection should be encrypted

• Repeat the test for www.api.com