Gracefully Handling Website Errors in Django Production

Errors are an inevitable part of web development. However, how you handle these errors can significantly impact the user experience and your ability to diagnose and fix issues. In this post, we'll explore how to gracefully handle common website errors like 500, 403, and 404 in your Django production environment. Django provides default pages for these errors, but it is better to customize these pages.

Understanding the Error Codes

Before diving into error handling, let's quickly recap what these error codes mean:

• 500 Internal Server Error: Something went wrong on the server. This is a generic error that can be caused by various issues, from code errors to server configuration problems.

• 403 Forbidden: The user is not authorized to access the requested resource.

• 404 Not Found: The requested resource could not be found.  

Implementing Robust Error Handling in Django

1. Logging Errors

The first step in handling errors is to log them. Django's built-in logging system is a great starting point. You can configure it to log different levels of errors to different files or even send email notifications.

import logging

logger= logging.getLogger(__name__)

def my_view(request):
  try:
        # Your code here
    except Exception as e:

       logger.error(f"An error occurred: {e}")

raise​

2. Customizing Error Pages

Django expects 404.html and similar template files to show error pages, and use its own default pages. You can add these files at your template folders and force Django to use them instead for example consider you have created a project level templates folder in your Django project by adding it to TEMPLATES in setting.py:

# django_project/settings.py
TEMPLATES = [
    {
        "BACKEND": "django.template.backends.django.DjangoTemplates",
        "DIRS": [BASE_DIR / 'templates']  # project level template
...

By adding 404.html, 403.html, and 500.html to this folder, in a production environment that DEBUG is set to False, these custom pages are shown.

Django also allows you to customize error pages to provide informative and user-friendly messages.

from django.shortcuts import render

def custom_error_404(request, exception):
    return render(request, '404.html', status=404)

def custom_error_500(request):
    return render(request, '500.html', status=500)

Add these functions to your urls.py file:

from django.urls import path
from .views import custom_error_404, custom_error_500

handler404 = 'your_app.views.custom_error_404'
handler500 = 'your_app.views.custom_error_500'

3. Handling Specific Error Types

You can handle specific error types using try-except blocks. For example, to handle a DoesNotExist error:

from django.shortcuts import get_object_or_404

def my_view(request, pk):
    try:
        obj = get_object_or_404(MyModel, pk=pk)
        # ...
    except MyModel.DoesNotExist:
        # Handle the error gracefully

4. Using Middleware

Middleware can be used to handle errors globally. For example, you can log all errors or redirect certain types of errors to specific views.

from django.http import HttpResponse
from django.utils import six

class MyMiddleware(object):
    def process_exception(self, request, exception):
        logger.error(f"Unhandled exception: {exception}")
        return HttpResponse(six.text_type(exception), status=500)

Additional Tips

• Use a good debugging tool to inspect error messages and stack traces in detail.

• Monitor your production environment for errors and performance issues.

• Test your error handling code thoroughly.

Handling errors gracefully in your Django production is very important for user experience and satisfaction. By following these guidelines, you can create a more resilient and user-friendly Django application. Remember, a well-handled error can turn a negative experience into a positive one.