Fix database error with long domain names in scan results directory

[fschledorn]

Fix: Database Error with Long Domain Names

Resolves #1519 - django.db.utils.DataError: value too long for type character varying(100)

Bug

Django crashes with a database error when scanning domains with long names. This happens during scan initialization when saving the ScanHistory object - specifically when the results_dir field exceeds PostgreSQL's 100-character varchar limit.

Root Cause

The results_dir field was constructed using domain names directly:

scan.results_dir = f'{results_dir}/{domain.name}_{scan.id}'

With long domains, this easily breaks the 100-character PostgreSQL limit:

/usr/src/app/scan_results/really-really-long-subdomain-name.example.com_123
└─ 86+ characters (approaching/exceeding limit)

Fix

Switched from using unpredictable domain names to predictable domain IDs in paths:

Before: domain-name.example.com_123 (unpredictable length)
After: domain_42_scan_123 (always <50 chars)

Changes Made

1. Added utility function for consistent path generation:

   def get_scan_results_dir(results_base_dir, domain_id, scan_id):
       return f'{results_base_dir}/domain_{domain_id}_scan_{scan_id}'

2. Updated scan initialization to use the new function:

   scan.results_dir = get_scan_results_dir(results_dir, domain.id, scan.id)

3. Increased database field limit from 100 to 500 characters as a safety net

4. Added migration to update existing installations safely

Files Changed

• web/reNgine/tasks.py - Updated scan initialization logic
• web/reNgine/common_func.py - Added utility function
• web/startScan/models.py - Increased field length
• web/startScan/migrations/0003_increase_results_dir_length.py - Database migration

Testing

The migration is safe to run on production - it only increases field capacity and the new naming scheme ensures paths stay well under limits.

To test:

python manage.py migrate startScan

Then try scanning a domain with a long name (>32 characters) - it should work without database errors.

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