Django Error Logger

Keep It Simple and Stupid replacement of Sentry for error logging in django project.

A Django application that logs HTTP 500 errors to the database, capturing detailed context including user information, request details, and POST data.

Features

• Automatic Error Logging: Captures all unhandled exceptions (HTTP 500 errors)
• User Context: Logs the authenticated user when the error occurred
• Request Details: Captures path, method, headers, IP address, and query string
• POST Data Logging: Saves POST/PUT/PATCH payloads with sensitive field redaction
• Large Payload Protection: Filters out POST payloads larger than 100KB
• HTML Traceback: Stores Django's debug error page HTML for detailed debugging
• User Impersonation: Link to impersonate the user and reproduce the error (optional)
• Django Admin Integration: View and manage error logs through Django admin

Installation

pip install django-error-logger

🚀 Quick Integration

After installation, integrate into your Django project:

Step 1: Add to INSTALLED_APPS

Edit settings.py:

INSTALLED_APPS = [
    'django.contrib.admin',
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.sessions',
    'django.contrib.messages',
    'django.contrib.staticfiles',
    # ... your other apps ...
    'error_logger',  # Add this
]

Step 2: Add Middleware

Edit settings.py:

MIDDLEWARE = [
    'django.middleware.security.SecurityMiddleware',
    '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',
    # ... your other middleware ...
    'error_logger.middleware.ErrorLoggingMiddleware',  # Add at the end
]

Step 3: Add URLs

Edit your main urls.py:

from django.contrib import admin
from django.urls import path, include

urlpatterns = [
    path('admin/', admin.site.urls),
    # ... your other URLs ...
    path('error-logger/', include('error_logger.urls')),  # Add this
]

Step 4: Run Migrations

python manage.py migrate error_logger

Step 5: Test It

# Start your Django server
python manage.py runserver

# Trigger a test error (development only!)
curl http://localhost:8000/error-logger/test/500/

# Check Django admin
open http://localhost:8000/admin/error_logger/errorlog/

Step 6: User Permissions

To access the error logger views (such as the error log list, details, and test endpoints), users must be logged in and have the error_logger.view_errorlog permission. This permission is automatically created when you run migrations.

Assigning Permissions

You can assign this permission to users or groups via the Django admin interface:

1. Go to the Django admin at /admin/.
2. Navigate to Users or Groups.
3. Select a user or group.
4. In the permissions section, check the box for Can view error log under the Error logger app.
5. Save the changes.

Alternatively, you can assign permissions programmatically in your code or via fixtures.

Note: Only users with this permission can access the error logger URLs. Ensure your authentication system is properly configured.

---

🔧 Optional: User Impersonation Feature

To enable the "impersonate user" feature in admin:

pip install django-su

Then add to settings.py:

INSTALLED_APPS = [
    # ...
    'django_su',
    'error_logger',
]

And add to urls.py:

urlpatterns = [
    # ...
    path('su/', include('django_su.urls')),
]

---

⚠️ Production Considerations

Before deploying to production:

1. Remove Test Endpoints: Comment out or remove test views in error_logger/views.py
2. Access Control: Ensure only admin users can access /error-logger/ URLs
3. Log Cleanup: Implement a strategy to clean up old error logs
4. Review Sensitive Fields: Customize the SENSITIVE_FIELDS list for your app
5. Database Size: Monitor error log table size

---

Configuration

Sensitive Fields

The following fields are automatically redacted in POST data logs:

• password, password1, password2, old_password, new_password
• token, access_token, refresh_token, api_key, secret
• credit_card, cvv, ssn, pin

You can customize this list in middleware.py:

SENSITIVE_FIELDS = [
    'password', 'token', 'api_key', 'secret',
    # Add your custom sensitive fields here
]

POST Data Size Limit

By default, POST payloads larger than 100KB are not logged in full. You can adjust this in middleware.py:

MAX_POST_SIZE = 100 * 1024  # 100KB (default)
# MAX_POST_SIZE = 1024 * 1024  # 1MB

Usage

Django Admin

Access the error logs through Django admin at /admin/error_logger/errorlog/

Features:

• List view with error type, time, user, path, and method
• Filter by error type, time, and method
• Search by error message, path, or username
• Detail view with full traceback and HTML error page
• "Open in Full Page" button to view the HTML traceback
• "Impersonate and visit error page" button (requires django_su)

Test Endpoints

⚠️ Important: These endpoints should only be accessible in development/testing environments. Remove or restrict access in production.

Access these endpoints at /error-logger/test/:

1. Simple 500 Error

URL: /error-logger/test/500/

Triggers a ZeroDivisionError to test basic error logging.

curl http://localhost:8000/error-logger/test/500/

2. ValueError Test

URL: /error-logger/test/value-error/

Triggers a ValueError with a custom message.

curl http://localhost:8000/error-logger/test/value-error/

3. KeyError Test

URL: /error-logger/test/key-error/

Triggers a KeyError by accessing a non-existent dictionary key.

curl http://localhost:8000/error-logger/test/key-error/

4. POST Error Test

URL: /error-logger/test/post-error/

Tests error logging with POST data including sensitive fields (password, token).

Form Fields:

• username: Regular text field
• password: Will be redacted in logs
• email: Email field
• token: Will be redacted in logs

Usage:

1. Visit the URL in your browser
2. Fill out the form (pre-populated with test data)
3. Submit the form to trigger an error
4. Check Django admin to see POST data with sensitive fields redacted

cURL Example:

curl -X POST http://localhost:8000/error-logger/test/post-error/ \
  -H "Content-Type: application/x-www-form-urlencoded" \
  -d "username=testuser&password=secret123&email=test@example.com&token=abc123"

5. Large POST Error Test

URL: /error-logger/test/large-post-error/

Tests error logging with a large POST payload (150KB) that exceeds the logging limit.

Form Fields:

• username: Regular text field
• password: Will be redacted in logs
• large_field: Pre-filled with 150KB of data

Usage:

1. Visit the URL in your browser
2. Submit the form (large_field is pre-populated)
3. Check Django admin to see that POST data size is logged but content is not

Expected Result: The error log's additional_info should contain:

{
  "post_data": {
    "error": "POST payload too large to log",
    "size_bytes": 153600,
    "size_kb": 150.0,
    "size_mb": 0.15
  }
}

Model Structure

ErrorLog Model

Field	Type	Description
user	ForeignKey	User who encountered the error (null if anonymous)
error_message	TextField	Plain text exception message
error_type	CharField	Exception class name (e.g., "ValueError")
traceback	TextField	Plain text Python traceback
html_traceback	TextField	HTML version of Django's debug page
error_time	DateTimeField	When the error occurred
path	CharField	Request path
method	CharField	HTTP method (GET, POST, etc.)
user_agent	CharField	User's browser/client
ip_address	GenericIPAddressField	Client IP address
query_string	TextField	URL query parameters
additional_info	JSONField	POST data and request headers

Security Considerations

1. Sensitive Data: Always review the SENSITIVE_FIELDS list to ensure all sensitive data in your application is redacted
2. Access Control: Error logs contain sensitive information. Ensure only authorized users (admin group) can access them
3. Test Endpoints: Remove or restrict access to test endpoints in production
4. Database Storage: Error logs can accumulate. Implement a cleanup strategy (e.g., delete logs older than 90 days)
5. HTML Traceback: Contains full request context. Ensure admin access is properly secured

Requirements

• Django 3.2+
• Python 3.8+
• django_su (for user impersonation feature)

License

AGPL-3.0