Deploy Django app with Nginx, Gunicorn, PostgreSQL & Supervisor in Linux— 2021

Currently we have latest deployment steps using docker or CI or CD tools. Even though I am writing this blogs for those who are beginner and want to deploy manually.

Installation based on :

Python3 , Django, Supervisor, Gunicorn, Postgres , Nginx

1. First start with the updating packages that are already available on server.

$ sudo apt-get update
$ sudo apt-get upgrade

2. Install python3 and basic system dependencies

$ sudo apt install python-is-python3
$ sudo apt install python3-pip python3-dev libpq-dev postgresql postgresql-contrib nginx python3.8-venv supervisor

3. PostgreSQL setup ( Optional )

$ sudo -u postgres psql
CREATE DATABASE myproject;
CREATE USER myprojectuser WITH PASSWORD 'password';
ALTER ROLE myprojectuser SET client_encoding TO 'utf8';
ALTER ROLE myprojectuser SET default_transaction_isolation TO 'read committed';
ALTER ROLE myprojectuser SET timezone TO 'UTC';
GRANT ALL PRIVILEGES ON DATABASE myproject TO myprojectuser;
\q
-------
If you want to Change postgres user password:
ALTER USER postgres PASSWORD 'myPassword';

4. Create environment and and install the requirements using requirements.txt

python -m venv env
source env/bin/activate
pip install -r requirements.txt 
install below libs if not add in requirements.txt 
 - pip install psycopg2
 - pip install gunicorn

5. Changes in the settings.py

ALLOWED_HOSTS = ['<your server's IP or domain name>']
...
...
DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.postgresql_psycopg2',
        'NAME': 'django_db',
        'USER': 'db_user',
        'PASSWORD': '<password you entered when creating db_user>',
        'HOST': 'localhost',
        'PORT': '5432',                      # Set to empty string for default.
    }
}

6. Now you have gunicorn working, test it by running

gunicorn myproject.wsgi:application --bind 0.0.0.0:8001

7. If it works,

Let make it more configure. Create bash file and paste below code.

#!/bin/bash

NAME="myproject"                        # Name of the application
DJANGODIR=/home/ubuntu/myproject         # Django project directory
SOCKFILE=/home/ubuntu/run/gunicorn.sock  # communicate through unix socket
USER=ubuntu                              # the user to run as
GROUP=ubuntu                             # the group to run as
NUM_WORKERS=3                            # processes Gunicorn spawn
DJANGO_SETTINGS_MODULE=myproject.settings      # which settings file should Django use
DJANGO_WSGI_MODULE=myproject.wsgi              # WSGI module name
echo "Starting $NAME as `whoami`"

# Activate the virtual environment

cd $DJANGODIR
source /home/ubuntu/env/bin/activate
export DJANGO_SETTINGS_MODULE=$DJANGO_SETTINGS_MODULE
export PYTHONPATH=$DJANGODIR:$PYTHONPATH

# Create the run directory if it doesn't exist

RUNDIR=$(dirname $SOCKFILE)
test -d $RUNDIR || mkdir -p $RUNDIR

# Start your Django Unicorn
# Programs meant to be run under supervisor should not daemonize themselves (do not use --daemon)

exec gunicorn ${DJANGO_WSGI_MODULE}:application \
  --name $NAME \
  --workers $NUM_WORKERS \
  --user=$USER --group=$GROUP \
  --bind=unix:$SOCKFILE \
  --log-level=debug \
  --log-file=-

Now make this script executable.

$ sudo chmod u+x gunicorn_start.bash

8. To supervise any program through supervisor, you need to create configuration file. Create file — /etc/supervisor/conf.d/myproject.conf

Copy below content and paste it on above created file ( myproject.conf )

[program: myproject]
command = /home/ubuntu/gunicorn_start.bash
user = ubuntu
stdout_logfile = /home/ubuntu/logs/gunicorn_supervisor.log
redirect_stderr = true 
environment=LANG=en_US.UTF-8,LC_ALL=en_US.UTF-8        

9. Create log file

mkdir -p /home/ubuntu/logs/
touch /home/ubuntu/logs/gunicorn_supervisor.log

10. Now for supervisor we should reread configuration files and update it so the our newly configuration file get add.

$ sudo supervisorctl reread
$ sudo supervisorctl update
# For Ubuntu 16.04 + :
$ sudo systemctl restart supervisor
$ sudo systemctl enable supervisor
# For all services
$ sudo supervisorctl status all
$ sudo supervisorctl start all 
$ sudo supervisorctl stop all
$ sudo supervisorctl restart all

11. For Nginx configuration:

create nginx configuration file for our application inside /etc/nginx/sites-available/ directory. create file with .conf extension.

upstream my_project_server {
  # fail_timeout=0 means we always retry an upstream even if it failed
  # to return a good HTTP response (in case the Unicorn master nukes a
  # single worker for timing out).
  server unix:/home/ubuntu/run/gunicorn.sock fail_timeout=0;
}

server {

    listen   80;
    server_name <your domain name>;

    client_max_body_size 4G;
    access_log /home/ubuntu/logs/nginx-access.log;
    error_log /home/ubuntu/logs/nginx-error.log;

    location /static/ {
        alias   /home/ubuntu/myproject/static/;
    }

    location /media/ {
        alias   /home/ubuntu/myproject/media/;
    }

    location / {

        # an HTTP header important enough to have its own Wikipedia entry:
        #   http://en.wikipedia.org/wiki/X-Forwarded-For
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;


        # enable this if and only if you use HTTPS, this helps Rack
        # set the proper protocol for doing redirects:
        # proxy_set_header X-Forwarded-Proto https;

        # pass the Host: header from the client right along so redirects
        # can be set properly within the Rack application
        proxy_set_header Host $http_host;

        # we don't want nginx trying to do something clever with
        # redirects, we set the Host: header above already.
        proxy_redirect off;

        # set "proxy_buffering off" *only* for Rainbows! when doing
        # Comet/long-poll stuff.  It's also safe to set if you're
        # using only serving fast clients with Unicorn + nginx.
        # Otherwise you _want_ nginx to buffer responses to slow
        # clients, really.
        # proxy_buffering off;

        # Try to serve static files from nginx, no point in making an
        # *application* server like Unicorn/Rainbows! serve static files.
        if (!-f $request_filename) {
            proxy_pass http://sample_project_server;
            break;
        }
    }

    # Error pages
    error_page 500 502 503 504 /500.html;
    location = /500.html {
        root /home/ubuntu/myproject/static/;
    }
}

12. After this we will need to create symbolic link for it, in the /etc/nginx/sites-enabled directory.

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

13. Now, start the Nginx.

$ sudo service nginx start
or
$ sudo /etc/init.d/nginx restart