Django i18n_patterns Redirection Issue in Production

Based on your description, it sounds like you're experiencing an issue with the internationalization middleware in Django 4.2.16. This could be related to a few recent issues that have been addressed in Django's internationalization framework.

Potential Causes

1. LocaleMiddleware Configuration: The issue might be related to the LocaleMiddleware which handles language code processing. Django 4.2.15 fixed a regression that caused crashes in LocaleMiddleware when processing language codes over 500 characters (ticket #35627).

2. Middleware Order: Check if the middleware order in your settings is correct. LocaleMiddleware should be placed after SessionMiddleware and CommonMiddleware.

3. Nginx Configuration: Your Nginx configuration might be affecting how URLs are passed to Django. Check if there are any rewrite rules or proxy settings that could be interfering with the language prefix.

4. Recent Security Patches: Django has addressed several internationalization-related security issues, including a potential denial-of-service vulnerability in django.utils.translation.get_supported_language_variant() (CVE 2024-39614) and another related to internationalized URLs (CVE 2022-41323).

Troubleshooting Steps

1. Verify Middleware Configuration:

   PYTHONCopied
   MIDDLEWARE = [
       'django.middleware.security.SecurityMiddleware',
       'django.contrib.sessions.middleware.SessionMiddleware',
       'django.middleware.locale.LocaleMiddleware',  # Make sure this is in the correct position
       'django.middleware.common.CommonMiddleware',
       # other middleware...
   ]

2. Check i18n Settings:

   PYTHONCopied
   USE_I18N = True
   LANGUAGE_CODE = 'en'
   LANGUAGES = [
       ('en', 'English'),
       # other languages...
   ]

3. Verify i18n_patterns Usage:

   PYTHONCopied
   from django.conf.urls.i18n import i18n_patterns
   from django.urls import path
   
   urlpatterns = i18n_patterns(
       path('about/', views.about, name='about'),
       # other URL patterns...
       prefix_default_language=True  # Make sure this is set to True if you want /en/ prefix
   )

4. Check Nginx Configuration: Ensure that your Nginx configuration is correctly passing the full URL path to Django, including any language prefixes.

5. Debug with Logging: Your approach to add logging is good. Focus on:

   • django.middleware.locale
   • django.utils.translation
   • Request/response cycle in your middleware

Additional Considerations

Since you mentioned that the issue appeared after changing users and directory locations, check if there are any permission issues with locale files or if environment variables related to localization might be different between the two setups.

Also, verify that the LOCALE_PATHS setting is correctly pointing to your locale directories in the new setup.

Let me know what you find from your debugging efforts, and we can further diagnose the issue.