How to deploy a Django application to HostPresto!

In this tutorial we will deploy a Django Polls project from the official Django tutorial to a HostPresto! Hosting package.

If you have started learning Django framework, you should be familiar with this tutorial project. Moreover, you should have this project on your local machine up and running, using the Django built-in development webserver. Now we will deploy this project to your HostPresto! Hosting package.

If you do not have the project on your machine, you may just clone my
GitHub repository:

https://github.com/vallka/django-polls/

(How to run the Polls project locally is out of scope of this tutorial. Please refer to official docs to set up a local development environment and build the project):
https://docs.djangoproject.com/en/3.0/intro/tutorial01/. )

Here we will assume that you have the project set up on your local virtual environment. The project should have the following or similar structure on your machine:

└───mysite
  │   db.sqlite3
  │   manage.py
  │   README.md
  │   requirements.txt
  ├───mysite
  │       settings-production.py.sample
  │       settings.py
  │       urls.py
  │       wsgi.py
  │       __init__.py
  ├───polls
  │   │   admin.py
  │   │   apps.py
  │   │   models.py
  │   │   tests.py
  │   │   urls.py
  │   │   views.py
  │   │   __init__.py
  │   ├───migrations
  │   │       0001_initial.py
  │   │       __init__.py
  │   ├───static
  │   │   └───polls
  │   │       │   style.css
  │   │       └───images
  │   │               background.jpg
  │   └───templates
  │       └───polls
  │               detail.html
  │               index.html
  │               results.html
  └───templates
      └───admin
              base_site.html

Let’s start to set up our HostPresto! Environment..

Creating a subdomain

Suppose you have a domain registered with HostPresto! – yourname.xyz

For this tutorial, we will create a subdomain: polls.yourname.xyz

We think this is the most natural and straightforward method as setting up the tutorial project in the root domain may pollute your space.
You may also have an existing website sitting there already. Adding a subdirectory like www.yourname.xyz/polls is less convenient, in our opinion.

Log in into cPanel and click on Subdomains in DOMAINS section. Enter ‘polls’ into Subdomain field.
Select your main domain (yourname.xyz) from the Domain dropdown.
Document Root will be auto populated with ‘polls.yourname.xyz’. Let’s accept the default value.
Click Create.

Subdomain created. If you point your browser to
http://polls.yourname.xyz, You should see a directory listing – something like this:

This is how an empty website will appear on HostPresto! Hosting packages.

Setting up Python application

In cPanel go to the SOFTWARE section and select Setup Python App. Click on CREATE APPLICATION.

HostPresto! Uses software from Passenger (https://www.phusionpassenger.com/) to set up Python applications. The setup page isn’t very intuitive, in my opinion. But let’s use it anyway.

Select the latest Python version in the first field. It is 3.7.3 at the moment of writing.
In Application root type in the directory name we have created in the previous step, relating to your home directory – that is, just ‘polls.yourname.xyz’. Select ‘polls.yourname.xyz’ as the Application URL in the next line.
Leave Application startup file and Application Entry point empty – the system will create this file by its own rules.
Last thing – it is sensible to name a logfile (Passenger log file) – enter /home/yournamexy/polls.log (replacing yournamexy with your cPanel username)

Click on CREATE

Click on START APP

Again, point your browser to http://polls.yourname.xyz (or refresh the page if you still have it in open in one of your browser tabs). Now it should show something like this:

This means we have successfully created a virtual environment for our Python application.

Uploading project files.

To upload files we will use any FTP client. You can find your FTP information (FTP host, port, credentials) from the FILES – FTP Accounts section of your cPanel. Remember to use your cPanel username and password (the ones you can find on your Welcome email), not your HostPresto! Client area email/password. (You can also connect via SFTP using the same cPanel credentials. Please note however that you need to use port 88 for SFTP, not the standard port 22. )

You can even use cPanel File Manage to upload files, but this can be cumbersome if uploading a lot of separate files, in my opinion.

Once logged in to FTP, Navigate to the newly created directory polls.yourname.xyz. This will be the root directory for our project, corresponding to ‘outer mysite/’ directory mentioned in the Django Polls tutorial.
Upload the whole structure here. (Ensure that manage.py file resides directly in the polls.yourname.xyz directory)

We will need the requirements.txt file, which should also live in the root project directory – polls.yourname.xyz. Most likely you already have this file in you project directory on your local machine, so it will have already uploaded to the server. But if there is no such file, you need to create it.
For this, go to your project directory on your local machine, activate your project virtual environment (running command source /path/to/ENV/bin/activate or similar method), then run the following command:

pip freeze > requirements.txt

This will create the requirements.txt file. The content of this file should look something like this:

asgiref==3.2.3
Django==3.0
pytz==2019.3
sqlparse==0.3.0

Numbers may differ and there may be more lines, but it shouldn’t matter for now.

Upload this file to root project directory (polls.yourname.xyz) if it is not already there.

Installing Python packages

Once we have a virtual environment, we have to install the needed packages. How to do this, is not particularly clear from the cPanel web interface.

Yes, we can do it directly from the web interface (by going to the ‘requirements.txt’ file – if you have this file in root subdirectory. In the ‘Configuration files’ section, click ADD, then click ‘Run Pip install’), but we won’t do it this way. Let’s do it the traditional way, via running shell commands. We will need to use shell commands anyway, so let’s go to the command line straight away.

We need to make a ssh connection to our server. If you are on Windows, I recommend to use a program called PuTTY. Use your cPanel username and password (not client area password!) and change port 22 to 88 for the ssh connection.

Once logged in, activate your project virtual environment and cd into project directory. How do you do this? Actually cPanel contains a useful hint: at the top of the page the command is displayed:

Enter to the virtual environment. To enter to virtual environment, run the command:

source /home/yournamexy/virtualenv/polls.yourname.xyz/3.7/bin/activate && cd /home/yournamexy/polls.yourname.xyz

Just click on the command shown and it will be copied to the clipboard.

Paste the command in to the PuTTY terminal window and run it – now you are in your project directory and the virtual environment is activated. First of all, let’s upgrade pip – run the command:

pip install --upgrade pip

Now we can install python packages needed for the project. Remember, we have a list in requirements.txt file. Run the following command:

pip install -r requirements.txt

After some busy work of the system, all needed packages are installed.

First attempt to run

You should already know that first we need to (re)create a database. For this, the following command is needed:

python manage.py migrate

Run it. Most probably, you will get a long list of errors. The very last line contains the actual error, something like this:

django.core.exceptions.ImproperlyConfigured: SQLite 3.8.3 or later is required (found 3.7.17).

Actually, this is good that we ran into this error in the very first step. (If not and your migration completed successfully you still need to read further!). As you may remember, for local development you have used SQLite server, built-in Python SQL server. This is completely fine
for local development, but totally unacceptable for the production server (and we are pretending to deploy to production server now). So luckily for us, Django doesn’t like the version of installed SQLite server, so there is no other way than to switch to MySQL. (Traditionally Django uses PostgreSQL but in our case we have MySQL pre-installed on the server, so we will use MySQL)

So let’s return to cPanel and create a MySQL database, using the available cPanel tools.

Creating MySQL database for the project

This is easy. In cPanel, go to DATABASES – MySQL Database Wizard. Type in a name for a database. Let’s call it ‘polls’ in order to be consistent. cPanel automatically prefixes the database name with yournamexy_, so the full name will be ‘yournamexy_polls’.
Click on Next Step, provide a name and a password for new database user (let’s give the user the same name: ‘yournamexy_polls’).
Provide a password – Don’t forget to make a note of the newly created password – we’ll need it in a minute.
Click Next.
On Step 3 check ALL PRIVILEGES. Click Next.

Creating settings-production.py file

Now we have to alter our settings.py file – to change the SQLite database for MySQL. How will we do it?

Updating the settings.py file itself is not a good idea. Yes, we can do it, directly on the server, but we won’t be able to use this file on a local computer. How to solve it? Usually a project has two or more settings.py files – one for the dev server, one for production, and possibly one
for a staging server. We will create a second file for production – let’s call it settings-production.py

I recommend to do it on your local machine and upload it to the server afterwards. So navigate to the ‘inner mysite/’ directory on your local machine.

File settings.py should be there, so alongside this file create a new file called settings-production.py. Then put the following line at the top of the file:

from . settings import *

This simply imports all settings from our existing settings.py file. Now we need to override some of them. Let’s do it one by one, to make things clear, what and why we are overriding.

First of all, we need to change DATABASES. So add the following lines:

DATABASES = {
  'default': {
      'ENGINE': 'django.db.backends.mysql',
      'NAME': 'yournamexy_polls',
      'USER': 'yournamexy_polls',
      'PASSWORD': os.environ['POLLS_DB_PASSWORD'],
      'HOST': 'localhost',
  }
}

(Replace yournamexy_polls with your own name you have created in the previous “Creating MySQL database” step)

It’s not a good idea to hardcode the database password, so we will read it from the environment variable.

Upload the file to the server

Running manage.py on production server

How should we tell Django to use setting-production.py instead of settings.py? All we need is to set an environment variable:

DJANGO_SETTINGS_MODULE

So within your Putty ssh session, run:

export DJANGO_SETTINGS_MODULE=mysite.settings-production

Remember, we also need to set a variable for the database password:

export POLLS_DB_PASSWORD=

(Use the password you have chosen when creating the database)

Now we are ready to run migration in the production environment. Run again:

python manage.py migrate

Now it should finish successfully.

You may find that it ended with an error – complaining that ‘package mysqlclient not found’. In this case you simply need to install the needed package:

pip install mysqlclient

Next, create a superuser:

python manage.py createsuperuser

Now we need to finish configuring the Python applications

Configuring passenger\_wsgi.py

Return to your cPanel – Setting Python App page. You will see that the Application startup file and Application Entry point fields are populated now.

The Application startup file is called passenger_wsgi.py – Find this file in the root folder of our project, open it in File Manager. It should look like this:

import os
import sys

sys.path.insert(0, os.path.dirname(__file__))

def application(environ, start_response):
  start_response('200 OK', [('Content-Type', 'text/plain')])
  message = 'It works!\n'
  version = 'Python %s\n' % sys.version.split()[0]
  response = '\n'.join([message, version])
  return [response.encode()]

We don’t need all this. So delete the content and replace it with the following:

import os

from django.core.wsgi import get_wsgi_application

os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'mysite.settings-production')
application = get_wsgi_application()

Note: if you have cloned my GitHub project, you should have a file called passenger_wsgi.py.sample. It is called .sample on purpose – the system will auto-create this file for us, so the initial content would be overwritten anyway. So rename the files or copy-paste the content from passenger_wsgi.py.sample to passenger_wsgi.py)

As you can see, DJANGO_SETTINGS_MODULE variable is set here. We also need to set out the database password. We can do it here as well (although this is not a very good idea if we going to check in this file to GitHub), or set up POLLS_DB_PASSWORD variable in cPanel.
What we’ll do in Environment variables section of Python Application page. Click ADD VARIABLE, type in POLLS_DB_PASSWORD and your password, click done. Then click SAVE on top of the page.

Finally, click RESTART Point your browser to http://polls.yourname.xyz
and refresh page. Most probably you will see:

DisallowedHost at /

Invalid HTTP_HOST header: 'polls.yourname.xyz'. You may need to add 'polls.yourname.xyz' to ALLOWED_HOSTS.

Thankfully, the message is very clear. ALLOWED_HOSTS = [] in settings.py, that is fine for development. Now we need to override this setting for production. Open settings-production.py and add the following line:

ALLOWED_HOSTS = ['polls.yourname.xyz']

(Replace ‘yourname.xyz’ with your actual subdomain)

RESTART the application again and refresh the site in your browser:

Page not found (404)
Request Method:     GET
Request URL:    http://polls.yourname.xyz/

Ok, this is expected. Remember, there is no ‘/’ path defined for urlpatterns in urls.py (unless you have added it of course). Navigate to http://polls.yourname.xyz/polls –

No polls are available.

This is exactly what we expected to see. Navigate to http://polls.yourname.xyz/admin

You can log in using the superuser username and password generated previously, and create some polls now.

Static Files

Ok, everything seems to be working now…​ but where is my background? And the admin panel looks like it has lost all css styles…​ In fact it did.

Remember, .css, .js, image files are not served by default by Django on production servers. They are on the local development server, but to use them on a production a few more steps are needed. Actually, there are two ways to add static files to production websites – an easy one and…​ not so easy
one, but recommended by Django and supported out of the box.

Let’s start with the second one, the more complicated default Django way. This will give us a better understanding of Django.

According to Django philosophy, all static files must be placed on another webserver. Let’s simulate this another webserver with a second subdomain. Let’s create a subdomain called ‘polls-static’.
On cPanel, click on Subdomains in the DOMAINS section.
Enter ‘polls-static’ into the Subdomain field.
Select your main domain (yourname.xyz) from the Domain dropdown.
Accept the auto populated value for the subdomain root – ‘polls-static.yourname.xyz’.
Click Create.

Now we have a separate subdomain where we will put our static files. Open your existing settings-production.py in File Manager – Edit file and add two more lines:

STATIC_ROOT = '/home/yournamexy/polls-static.yourname.xyz/'
STATIC_URL = 'http://polls-static.yourname.xyz/'

(Remember to replace “yournamexy” with your cPanel username)

You may remember that settings.py already contains a line:

STATIC_URL = '/static/'

In settings-production.py we have overridden this value with a new one.
STATIC_ROOT is a new setting, we didn’t have it at development, as it wasn’t needed.

Now go to your SSH terminal. If you logged off, log back in. Important! Do not forget to activate and cd into you virtual environment (as previously shown) and export the environment variables:

source /home/yournamexy/virtualenv/polls.yourname.xyz/3.7/bin/activate && cd /home/yournamexy/polls.yourname.xyz

Then:

export DJANGO_SETTINGS_MODULE=mysite.settings-production

Then:

export POLLS_DB_PASSWORD=

These commands are saved in bash history, so it will be easy to repeat them. (You may add them to your .bashrc if you want them to be executed automatically upon log on)

Now run the following command:

python manage.py collectstatic

Type ‘yes’ if prompted

After a while you will see:

132 static files copied to '/home/yournamexy/polls-static.yourname.xyz'

All static files from different subdirectories of the polls project (including admin files) are now copied to the ‘/home/yournamexy/polls-static.yourname.xyz/’ directory. You can open it in File Manager to see it.

Now restart application on the Python Application page

Refresh polls.yourname.xyz/polls and polls.yourname.xyz/admin

Now all should be displayed exactly as it was on your local development server.

Look at the page source of the /polls/ page in your web browser. You may find a line:

<link rel="stylesheet" type="text/css" href="http://polls-static.yourname.xyz/polls/style.css">

If you have worked on local development server, you may recall that the same line looked like this:

<link rel="stylesheet" type="text/css" href="/static/polls/style.css">

You see, now, on production, style.css file (and other static files) are served from the other subdomain.

This is how it supposed to work with Django by default.

However, there is a simpler way.

Using WhiteNoise package for serving static files

All of the additional setup with the additional polls-static subdomain was required because Django wants us to put Python code and static files in two separate webservers – for the sake of efficiency. However, in our case, these two subdomains are still served by the same webserver. So why all
the additional efforts?

Luckily, adding one more package – WhiteNoise – allows us to reduce this headache.

Go to your ssh terminal and run:

pip install whitenoise

Next, edit settings.py – not settings-production.py, the main settings.py file. WhiteNoise works equally well in development and production environments. Add a line to MIDDLEWARE:

MIDDLEWARE = [
'django.middleware.security.SecurityMiddleware',
'whitenoise.middleware.WhiteNoiseMiddleware',  # new
'django.contrib.sessions.middleware.SessionMiddleware',
'django.middleware.common.CommonMiddleware',
'django.middleware.csrf.CsrfViewMiddleware',
'django.contrib.auth.middleware.AuthenticationMiddleware',
'django.contrib.messages.middleware.MessageMiddleware',
'django.middleware.clickjacking.XFrameOptionsMiddleware',
]

(it should be placed directly after ‘django.middleware.security.SecurityMiddleware’ according to WhiteNoise documentation)

Add this line at the end of the file, after STATIC_URL:

STATIC_ROOT = os.path.join(BASE_DIR, 'staticfiles')

‘staticfiles’ is a special name, known to WhiteNoise

Now comment out (or simply delete) the two lines in settings-production.py we added previously:

#STATIC_ROOT = '/home/yourname/polls-static.yourname.xyz/'
#STATIC_URL = 'http://polls-static.yourname.xyz/'

We don’t need them anymore.

In your ssh terminal, run collectstatic again:

python manage.py collectstatic

Restart your application and refresh the application pages. Now you will see the same working application, and references to static files within the page source will look exactly as on the development server, e.g.:

<link rel="stylesheet" type="text/css" href="/static/polls/style.css">

But don’t think that WhiteNoise package is for simplifying stuff only. If you really need it, with just a few configuration variables you can set up your static files on different servers, as before, or on cloud storage or CDN. So it can be beneficial for performance also if set up accordingly.

One last step

On production server, we shouldn’t forget to switch DEBUG off. So add the final line to settings-production.py:

DEBUG = False

All done.

We won’t go further in this tutorial. Now we have successfully deployed our application on our HostPresto! Hosting., and learned two different methods of serving static files.