the_inventory

Troubleshooting Guide

Common issues and solutions for The Inventory development.

CORS Errors

Symptom: Browser shows No 'Access-Control-Allow-Origin' header is present

Most Common Cause: Backend isn’t running.

Solution:

cd src
python manage.py runserver

You should see a CORS warning box - this is normal in development and means all origins are allowed.

Still not working?

1. Check frontend/.env.local has: NEXT_PUBLIC_API_URL=http://localhost:8000/api/v1
2. Verify both frontend and backend are running
3. Clear browser cache and reload

Production: Set CORS_ALLOWED_ORIGINS=https://your-domain.com in .env

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Network Access (Mobile/Other Devices)

To test on mobile or another computer:

1. Find your IP: ip addr show (Linux/Mac) or ipconfig (Windows)
2. Start Django: python manage.py runserver 0.0.0.0:8000
3. Access from device: http://YOUR_IP:3000

Development CORS allows this automatically - no configuration needed!

Firewall blocking?

• Linux: sudo ufw allow 3000 && sudo ufw allow 8000
• Mac/Windows: Allow Python/Node in firewall settings

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Database Issues

Migration errors:

cd src
rm db.sqlite3  # Development only!
python manage.py migrate
python manage.py createsuperuser
python manage.py seed_database --clear --create-default

PostgreSQL connection:

# Check .env format
DATABASE_URL=postgresql://username:password@host:port/database

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Authentication Issues

Can’t login:

1. Clear browser storage (F12 → Application → Clear site data)
2. Verify user exists: python manage.py createsuperuser
3. Check tenant membership: python manage.py seed_database --create-default

“No tenant membership” error:

cd src
python manage.py seed_database --create-default

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JWT Authentication 401 Errors (Production)

Symptom: Login works (200) but subsequent requests fail with 401 Unauthorized. Cookies appear in DevTools but aren’t being sent.

Root Cause Analysis

The issue depends on your domain setup:

Scenario 1: Different Domains (No Shared Parent)

Example: Frontend on vercel.app, Backend on onrender.com

Why it fails:

• Backend cannot set cookies on a different domain
• Browsers enforce same-origin policy
• Cookies set by onrender.com won’t be sent to vercel.app

Solution: Use token-based auth (Authorization header) instead of cookies

# Backend settings.py
JWT_COOKIE_DOMAIN = None  # Disable cookie-based auth

Scenario 2: Shared Parent Domain (Recommended)

Example: Frontend on theinventory.ndevuspace.com, Backend on api.theinventory.ndevuspace.com

Why it fails initially:

• JWT_COOKIE_DOMAIN = None means cookies are only valid for exact domain match
• Cookies set by backend aren’t sent to frontend because domain doesn’t match

Solution: Set cookie domain to shared parent domain

# Backend settings.py
JWT_COOKIE_DOMAIN = ".ndevuspace.com"  # Leading dot = all subdomains
JWT_COOKIE_SECURE = True               # Required for HTTPS
JWT_COOKIE_SAMESITE = "Lax"            # Safe for same parent domain

Why this works:

• .ndevuspace.com allows cookies to be shared between all subdomains
• Browser will include cookies in requests from theinventory.ndevuspace.com to api.theinventory.ndevuspace.com

Configuration Checklist

For shared parent domain setup:

1. ✅ Frontend and backend share parent domain

   Frontend:  theinventory.ndevuspace.com
   Backend:   api.theinventory.ndevuspace.com
   Parent:    ndevuspace.com (shared)
   

2. ✅ Backend environment variables set correctly

   JWT_COOKIE_DOMAIN=.ndevuspace.com
   JWT_COOKIE_SECURE=True
   JWT_COOKIE_SAMESITE=Lax
   

3. ✅ Frontend API URL points to backend

   NEXT_PUBLIC_API_URL=https://api.theinventory.ndevuspace.com/api/v1
   

4. ✅ CORS configured correctly

   CORS_ALLOWED_ORIGINS = [
       "https://theinventory.ndevuspace.com",
   ]
   CORS_ALLOW_CREDENTIALS = True
   

Verify the Fix

1. After login, check browser DevTools → Application → Cookies
2. Find access_token cookie
3. Verify Domain column shows .ndevuspace.com (with leading dot)
4. Verify Secure is checked (for HTTPS)
5. Check Network tab → /api/v1/auth/me/ request
6. Should see Cookie: access_token=... header
7. Response should be 200 (not 401)

If Still Failing

• Verify JWT_COOKIE_DOMAIN matches your domain setup
• Clear browser cookies and log in again
• Check backend logs for CORS errors
• Verify CORS_ALLOW_CREDENTIALS = True in backend
• Ensure frontend and backend are on HTTPS in production

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Development Environment

Port already in use:

# Find process
lsof -i :8000  # Linux/Mac
netstat -ano | findstr :8000  # Windows

# Kill it
kill -9 <PID>  # Linux/Mac
taskkill /PID <PID> /F  # Windows

Python environment issues:

deactivate
rm -rf venv
python3.12 -m venv venv
source venv/bin/activate
pip install -r requirements.txt

Node/Yarn issues:

cd frontend
rm -rf node_modules .next yarn.lock
yarn install

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Testing

Tests not discovered?

Ensure you’re running from the src/ directory:

cd src
python manage.py test

Want to run only seeder tests?

python manage.py test tests.seeders

Want to run a specific test?

python manage.py test tests.api.test_auth.AuthTestCase.test_login

Understanding test output:

The custom test runner automatically excludes seeder tests by default. You’ll see:

• ~1487 tests when running python manage.py test (seeders excluded)
• ~34 tests when running python manage.py test tests.seeders (seeders only)

This is intentional — seeder tests are only included when explicitly requested.

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# Backend
cd src
python manage.py runserver              # Start
python manage.py runserver 0.0.0.0:8000 # Network access
python manage.py migrate                # Migrations
python manage.py createsuperuser        # Admin user

# Frontend
cd frontend
yarn install    # Dependencies
yarn dev        # Start
yarn build      # Production build

# Database
python manage.py dbshell        # Database shell
python manage.py shell          # Django shell

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Still Stuck?

1. Check logs in terminal where servers are running
2. Check browser console (F12)
3. See Environment Guide for configuration
4. Report an issue

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