How to Set Up Django With Postgres, Nginx, and Gunicorn on Ubuntu 16.04

Introduction

Django is a free, open source, and high-level Python web framework that encourages rapid development and clean, pragmatic design. Django's MVC (Model-View-Controller) architecture is maintained by the Django Software Foundation. Django is a strong web framework that can assist you to get your application online as quickly as possible. The primary goal of Django is to ease the creation of complex, database-driven websites. Django supports four major database backends including, PostgreSQL, MySQL, SQLite, and Oracle.

You can run Django in conjunction with Apache, Nginx using WSGI, Gunicorn, or Cherokee using a Python module.

In this tutorial, we will learn how to install and configure Django with a PostgreSQL database on Alibaba Cloud Elastic Compute Service (ECS) Ubuntu 16.04. We will also learn to configure the Gunicorn application server to interface with our applications and set up Nginx to reverse proxy to Gunicorn.

Requirements

• A fresh Alibaba Cloud Ubuntu 16.04 instance with minimum 2GB of RAM.
• A static IP address is configured.
• A root password is set up on the server.

Launch Alibaba Cloud ECS Instance

First, log in to your Alibaba Cloud ECS Console. Create a new ECS instance, choosing Ubuntu 16.04 as the operating system with at least 2GB RAM. Connect to your ECS instance and log in as the root user.

Once you are logged into your Ubuntu 16.04 instance, run the following command to update your base system with the latest available packages.

apt-get update -y

Install Required Packages

Before starting, you will need to install Nginx, PostgreSQL, and some Python package to your system. You can install all of them with the following command:

apt-get install python3-pip python3-dev libpq-dev postgresql postgresql-contrib nginx -y

Once all the packages are installed. You can proceed to configure PostgreSQL database.

Configure PostgreSQL

Next, you will need to create a PostgreSQL database and user for the Django application.
First, log in to PostgreSQL's interactive session by running the following command:

sudo -u postgres psql

Next, create a PostgreSQL database and user for your Django project using the following commands:

postgres=# CREATE DATABASE testproject;
postgres=# CREATE USER testuser WITH PASSWORD 'password'; 

Next, setting the default encoding to UTF-8, setting the default transaction isolation scheme to "read committed," and setting the timezone to UTC with the following commands:

postgres=# ALTER ROLE testuser SET client_encoding TO 'utf8';
postgres=# ALTER ROLE testuser SET default_transaction_isolation TO 'read committed';
postgres=# ALTER ROLE testuser SET timezone TO 'UTC';

Next, grant all the privileges to your database and exit from the PostgreSQL session with the following commands:

postgres=# GRANT ALL PRIVILEGES ON DATABASE testproject TO testuser;
postgres=#  \q

Create a Python Virtual Environment

Next, you will need to create a Python virtual environment for your project. You can do that by installing the package required by Python within a virtual environment.

First, upgrade pip and install the virtual environment with the following commands:

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

Next, create a directory for your project:

mkdir ~/testproject
cd ~/testproject

Next, create a Python virtual environment by running the following command:

virtualenv testprojectenv

The above command will create a testprojectenv directory under the testproject directory and install a local version of Python and a local version of pip.

Next, you will need to install all the required packages for your project. First, activate the virtual environment with the following command:

source testprojectenv/bin/activate

After activating your virtual environment, install Django, Gunicorn, and the psycopg2 PostgreSQL adaptor with the following command:

(testprojectenv) root@mail:~/testproject# pip install django gunicorn psycopg2

Output:

Installing collected packages: pytz, django, gunicorn, psycopg2
Successfully installed django-2.1.1 gunicorn-19.9.0 psycopg2-2.7.5 pytz-2018.5

Configure a New Django Project

Next, you will need to tell Django to install the records inside your project directory. You can do this with the following command:

(testprojectenv) root@mail:~/testproject# django-admin.py startproject testproject ~/testproject

Next, you will need to define your server's IP address, database username, and password in the settings.py file:

(testprojectenv) root@mail:~/testproject# nano /root/testproject/testproject/settings.py

Make the following changes:

ALLOWED_HOSTS = ['192.168.43.192']

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.postgresql_psycopg2',
        'NAME':  'testproject',
        'USER' : 'testuser',
        'PASSWORD' : 'password',
        'HOST' : 'localhost',
        'PORT' : '',
    }
}

STATIC_ROOT = os.path.join(BASE_DIR, 'static/')

Save and close the file when you are done.

Next, you will need to migrate the initial database schema to our PostgreSQL database. You can do this by running the following script:

(testprojectenv) root@mail:~/testproject# ~/testproject/manage.py makemigrations
(testprojectenv) root@mail:~/testproject# ~/testproject/manage.py migrate

Next, create an administrative user for the project by running the following command:

(testprojectenv) root@mail:~/testproject# ~/testproject/manage.py createsuperuser

Output:

Username (leave blank to use 'root'): 
Email address: admin@example.com
Password: 
Password (again): 
Superuser created successfully.

Next, collect all of the static content into the directory location you have configured by running the following command:

(testprojectenv) root@mail:~/testproject# ~/testproject/manage.py collectstatic

Now, you can start your project by starting up the Django development server with the following command:

(testprojectenv) root@mail:~/testproject# ~/testproject/manage.py runserver 0.0.0.0:8000

Once the server has started successfully, you should see the following output:

Performing system checks...

System check identified no issues (0 silenced).
September 10, 2018 - 15:06:07
Django version 2.1.1, using settings 'testproject.settings'
Starting development server at http://0.0.0.0:8000/
Quit the server with CONTROL-C.

Now, open your web browser and type the following URL: http://your-server-ip:8000. You will be redirected to the Django index page as shown below:

You can also access Django's admin interface by typing the URL http://your-server-ip:8000/admin in your web browser. You will be prompted for the admin username and password (which you have created earlier) as shown below:

After entering username and password, click on the Login button. You will be redirected to the Django admin interface shown below:

Now, press CTRL+C in the terminal window to shut down the development server. No we can test whether Gunicorn can serve the application. To do so, enter the following command into your project's WSGI module:

(testprojectenv) root@mail:~/testproject# gunicorn --bind 0.0.0.0:8000 testproject.wsgi

The above command will start Gunicorn on the same interface that the Django development server was running on. You can test it by visiting http://your-server-ip:8000.

Once you have completed your testing, press CTRL+C in the terminal to stop the Gunicorn.

Now, deactivate your virtual environment by running the following command:

(testprojectenv) root@mail:~/testproject# deactivate

Create a Systemd Service File for Gunicorn

Next, you will need to create a systemd service file for Gunicorn. So, you can easily start and stop the application server. You can do this by creating the following file:

nano /etc/systemd/system/gunicorn.service

Add the following lines:

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

[Service]
User=root
Group=www-data
WorkingDirectory=/root/testproject
ExecStart=/root/testproject/testprojectenv/bin/gunicorn --access-logfile - --workers 3 --bind unix:/root/testproject/testproject.sock testproject.wsgi:application

[Install]
WantedBy=multi-user.target

Save and close the file. Then, start Gunicorn service and enable it to start on boot time with the following command:

systemctl start gunicorn
systemctl enable gunicorn

You can check the status of Gunicorn with the following command:

systemctl status gunicorn

Output:

● gunicorn.service - gunicorn daemon
   Loaded: loaded (/etc/systemd/system/gunicorn.service; enabled; vendor preset: enabled)
   Active: active (running) since Mon 2018-09-10 20:58:14 IST; 10s ago
 Main PID: 2377 (gunicorn)
   CGroup: /system.slice/gunicorn.service
           ├─2377 /root/testproject/testprojectenv/bin/python3 /root/testproject/testprojectenv/bin/gunicorn --access-logfile - --workers 3 --b
           ├─2384 /root/testproject/testprojectenv/bin/python3 /root/testproject/testprojectenv/bin/gunicorn --access-logfile - --workers 3 --b
           ├─2385 /root/testproject/testprojectenv/bin/python3 /root/testproject/testprojectenv/bin/gunicorn --access-logfile - --workers 3 --b
           └─2386 /root/testproject/testprojectenv/bin/python3 /root/testproject/testprojectenv/bin/gunicorn --access-logfile - --workers 3 --b

Sep 10 20:58:14 mail.example.com systemd[1]: Started gunicorn daemon.
Sep 10 20:58:14 mail.example.com gunicorn[2377]: [2018-09-10 20:58:14 +0530] [2377] [INFO] Starting gunicorn 19.9.0
Sep 10 20:58:14 mail.example.com gunicorn[2377]: [2018-09-10 20:58:14 +0530] [2377] [INFO] Listening at: unix:/root/testproject/testproject.soc
Sep 10 20:58:14 mail.example.com gunicorn[2377]: [2018-09-10 20:58:14 +0530] [2377] [INFO] Using worker: sync
Sep 10 20:58:14 mail.example.com gunicorn[2377]: [2018-09-10 20:58:14 +0530] [2384] [INFO] Booting worker with pid: 2384
Sep 10 20:58:15 mail.example.com gunicorn[2377]: [2018-09-10 20:58:15 +0530] [2385] [INFO] Booting worker with pid: 2385
Sep 10 20:58:15 mail.example.com gunicorn[2377]: [2018-09-10 20:58:15 +0530] [2386] [INFO] Booting worker with pid: 2386

Configure Nginx to Proxy Pass to Gunicorn

Gunicorn is now configured and working. It's time to configure Nginx to pass traffic to the process. You can do this by creating a new Nginx configuration file inside the /etc/nginx/sites-available/ directory.

nano /etc/nginx/sites-available/gunicorn

Add the following lines:

server {
    listen 80;
    server_name 192.168.43.192;

    location = /favicon.ico { access_log off; log_not_found off; }
    location /static/ {
        root /root/testproject;
    }

    location / {
        include proxy_params;
        proxy_pass http://unix:/root/testproject/testproject.sock;
    }
}

Save and close the file. Then, enable the Nginx virtual host by creating symlink:

ln -s /etc/nginx/sites-available/gunicorn /etc/nginx/sites-enabled/

Next, test Nginx for any configuration errors with the following command:

nginx -t

Output:

nginx: the configuration file /etc/nginx/nginx.conf syntax is ok
nginx: configuration file /etc/nginx/nginx.conf test is successful

Finally, restart Nginx by running the following command:

systemctl restart nginx

Now, Nginx is configured to pass the traffic to the process. To test it, open your web browser and type the URL http://your-server-ip. You will be redirected to your application as shown in the following page: