django-error-logger

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

Method 1: Install from PyPI (Recommended)

From any Django project:

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:

• Go to the Django admin at /admin/.
• Navigate to Users or Groups.
• Select a user or group.
• In the permissions section, check the box for Can view error log under the Error logger app.
• 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:

• Remove Test Endpoints: Comment out or remove test views in error_logger/views.py
• Access Control: Ensure only admin users can access /error-logger/ URLs
• Log Cleanup: Implement a strategy to clean up old error logs
• Review Sensitive Fields: Customize the SENSITIVE_FIELDS list for your app
• 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:

• Visit the URL in your browser
• Fill out the form (pre-populated with test data)
• Submit the form to trigger an error
• 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=[e-mail]&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:

• Visit the URL in your browser
• Submit the form (large_field is pre-populated)
• 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

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