Deploy the Django Application in EC2 Ubuntu Server Using ngnix & gunicorn

set up an ec2 instance 

edit inbound rule – allow all TCP & HTTP to 0.0.0.0/0

login to your instance using the ssh key (.pem key) 

ssh -i yourkey.pem ubuntu@instance_public_ip

Install python, pip, postgres & nginx to the instance

sudo apt update
sudo apt install python3-pip python3-dev libpq-dev postgresql postgresql-contrib nginx curl

make a folder and clone your repository to that folder

mkdir project 
cd project 
git clone githubrepolink

update the python package manage pip and install the virtualenv

sudo -H pip3 install --upgrade pip
sudo -H pip3 install virtualenv

make a virtualenv inside the project folder and activate it

virtualenv myprojectenv
source myprojectenv/bin/activate

move back inside the project folder > project and install all dependencies of requirements.txt file

pip install -r requirements.txt

make sure to allow the allowed host to specific ip or all of your django project’s settings.py

ALLOWED_HOSTS = ['*']

now you can try running the application to 0.0.0.0:8000

python manage.py runserver 0.0.0.0:8000

 you’ll be able to access the application in your instance public ip :8000

http://instancepublicip:8000

now although the application is running with the attached terminal if some issues evoked the terminal will be interupted and crashes the application so to automate the terminal from keep on restarting after the interuption, gunicorn is needed. To install the guicorn use 

pip install gunicorn

to check if the gunicorn is working

gunicorn --bind 0.0.0.0:8000 myproject.wsgi

now to make a persistent and robust way of starting and stopping the application is by making socket files and systemd service

sudo vi /etc/systemd/system/gunicorn.socket

[Unit]
Description=gunicorn socket

[Socket]
ListenStream=/run/gunicorn.sock

[Install]
WantedBy=sockets.target

now make the gunicorn.service file and paste your project dirs accordingly here

sudo nano /etc/systemd/system/gunicorn.service

[Unit]
Description=gunicorn daemon
Requires=gunicorn.socket
After=network.target

[Service]
User=ubuntu
Group=www-data
WorkingDirectory=/home/ubuntu/project/myprojectdir
ExecStart=/home/sammy/myprojectdir/myprojectenv/bin/gunicorn \
          --access-logfile - \
          --workers 3 \
          --bind unix:/run/gunicorn.sock \
          myproject.wsgi:application

[Install]
WantedBy=multi-user.target

start, enable and check the status of the gunicorn.socket file respectively

sudo systemctl start gunicorn.socket
sudo systemctl enable gunicorn.socket
sudo systemctl status gunicorn.socket

check if the sock file is working using curl

curl --unix-socket /run/gunicorn.sock localhost

if some problem arises, journalctl can be used to accessed the logs

sudo journalctl -u gunicorn

restart the gunicorn service 

sudo systemctl daemon-reload
sudo systemctl restart gunicorn

configure nginx proxypass to gunicorn; create a server block to the nginx sites-available dir

sudo nano /etc/nginx/sites-available/myproject

server {
    listen 80;
    server_name server_domain_or_IP;

    location = /favicon.ico { access_log off; log_not_found off; }
    location /static/ {
        root /home/ubuntu/project/myprojectdir/staticfiles;
    }

    location / {
        include proxy_params;
        proxy_pass http://unix:/run/gunicorn.sock;
    }
}

create a link from sites-available to sites-enabled

sudo ln -s /etc/nginx/sites-available/myproject /etc/nginx/sites-enabled

check if the syntax is okay

sudo nginx -t

restart the nginx service 

sudo systemctl restart nginx

openup the firewall to open traffic and remove the development server port 8000

sudo ufw delete allow 8000
sudo ufw allow 'Nginx Full'

incase of 502 Bad Gateway instead of the django application; check the nginx logs

sudo tail -F /var/log/nginx/error.log