Prepare your application for deployment

Completed

Set up your application for production by updating some of the most common settings.

Add libraries

You'll use two new libraries for your project:

• whitenoise to serve static files
• psycopg2-binary to connect to PostgreSQL, the production database

Install those libraries in your project:

1. In Visual Studio Code, open requirements.txt.

2. Add the following code to the end of requirements.txt.

   whitenoise
   psycopg2-binary
   

3. Open a new terminal pane by selecting Terminal > New terminal.

4. Install the libraries by running the following command.

   pip install -r requirements.txt
   

Create a production settings file

The values you assign to two core settings, ALLOWED_HOSTS and DATABASES, depend on the environment that hosts the application. The default settings are designed for development. To run your app in production, ensure these settings are updated properly.

ALLOWED_HOSTS controls the servers that are allowed to host or run your application. You'll configure it to allow the site to run from Azure and locally. DATABASES contains the list of available connection strings.

A common way to configure the settings is to create a second Python file that contains the collection of settings for production. Then a check at the end of the settings.py determines whether to use the production settings.

Now you'll create a production settings file and add the check to determine if your application is running in production:

1. Create a new file inside project. Name it azure.py.

2. Add the following code to import os.

   from .settings import *
   import os
   

3. Add the following code to the end of the file to override ALLOWED_HOSTS to allow Azure to host the application and to define trusted origins.

   ALLOWED_HOSTS = [os.environ['WEBSITE_HOSTNAME']] if 'WEBSITE_HOSTNAME' in os.environ else []
   CSRF_TRUSTED_ORIGINS = ['https://'+ os.environ['WEBSITE_HOSTNAME']] if 'WEBSITE_HOSTNAME' in os.environ else []
   

   Note

   Azure App Service automatically creates an environmental variable named WEBSITE_HOSTNAME. This variable contains the URL for your website. You can use this variable to determine whether your application is running on Azure.

4. Add the following code to configure the database connection string for PostgreSQL.

   hostname = os.environ['DBHOST']
   DATABASES = {
       'default': {
           'ENGINE': 'django.db.backends.postgresql',
           'NAME': os.environ['DBNAME'],
           'HOST': hostname + ".postgres.database.azure.com",
           'USER': os.environ['DBUSER'],
           'PASSWORD': os.environ['DBPASS'] 
       }
   }
   

   Note

   You'll set the environmental variables on Azure in a later step.

   Note

   The database connection is for PostgreSQL Flexible Server. For PostgreSQL Single Server, set the USER value to os.environ['DBUSER'] + "@" + hostname.

   The connection string you're using is for PostgreSQL. You provide the following information:

   • ENGINE: Database type
   • NAME: Name of the database
   • HOST: URL for the server
   • USER: Username to use to connect to the database
   • PASSWORD: Password for the user

5. Add the following code to the bottom of the file to enable whitenoise, which will serve static files.

   MIDDLEWARE = [
       'django.middleware.security.SecurityMiddleware',
       # Enables whitenoise for serving static files
       'whitenoise.middleware.WhiteNoiseMiddleware',
       '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',
   ]
   STATIC_ROOT = os.path.join(BASE_DIR, 'staticfiles')
   

   WhiteNoise is middleware that reads user requests for static files such as CSS or JavaScript. It also ensures the files are served correctly. You registered the middleware by updating the MIDDLEWARE array. You registered a STATIC_ROOT to store static files.

6. Set the SECRET_KEY with one read from environmental variables by adding the following code.

   SECRET_KEY = os.getenv('SECRET_KEY')
   

   You'll create a new secret key after you deploy the application and store it as an application setting.

7. Disable debugging mode by adding the following code.

   DEBUG = False
   

Configure your app to use the production settings file

Now that you've created the production settings file, you can update your application to load the file in production. Start by looking for the WEBSITE_HOSTNAME environmental variable. This variable indicates the application is running on Azure.

1. Open settings.py.

2. Add the following code to the end of the file to override the necessary settings when the app runs in production.

   import os
   if 'WEBSITE_HOSTNAME' in os.environ: # Running on Azure
       from .azure import *
   

3. Save all files by selecting File > Save all.

You've now configured a Django application for production.