gh-christianlouis-inboxconverge/MIGRATION_GUIDE.md

Migration Guide: Single-User to Multi-Tenant SaaS

This guide helps you migrate from the legacy single-user pop3_forwarder.py script to the new multi-tenant SaaS application.

Overview

The migration involves:

1. Understanding the architectural changes
2. Exporting existing configuration
3. Setting up the new system
4. Importing mail accounts
5. Verifying functionality
6. Decommissioning the old system

Architectural Changes

Before (Legacy)

• Single Docker container
• Environment variable configuration
• Direct POP3 fetching and SMTP forwarding
• No user accounts or authentication
• Limited to one Gmail destination

After (New System)

• Multi-container architecture (API, workers, database)
• Database-backed configuration
• User accounts with authentication
• Multiple users with separate configurations
• Web dashboard and API access
• Subscription tiers and limits

Prerequisites

• Access to existing .env file
• Docker and Docker Compose installed
• Basic understanding of REST APIs
• Access to Google Cloud Console (for OAuth)

Step-by-Step Migration

Step 1: Backup Existing Configuration

# Save your existing .env file
cp .env .env.legacy.backup

# Document your mail accounts
cat .env | grep POP3_ACCOUNT

Step 2: Set Up New System

# Pull latest changes
git pull origin main

# Create new environment file
cp backend/.env.example backend/.env

# Generate secure keys
echo "SECRET_KEY=$(openssl rand -hex 32)" >> backend/.env
echo "ENCRYPTION_KEY=$(openssl rand -hex 32)" >> backend/.env

Step 3: Start New Services

# Start all services
docker-compose -f docker-compose.new.yml up -d

# Wait for services to be ready
sleep 10

# Run database migrations
docker-compose -f docker-compose.new.yml exec backend alembic upgrade head

Step 4: Create Your User Account

Option A: Via API

# Register a new user
curl -X POST http://localhost:8000/api/v1/auth/register \
  -H "Content-Type: application/json" \
  -d '{
    "email": "your-email@example.com",
    "password": "your-secure-password",
    "full_name": "Your Name"
  }'

# Login to get access token
curl -X POST http://localhost:8000/api/v1/auth/login \
  -H "Content-Type: application/json" \
  -d "username=your-email@example.com&password=your-secure-password"

# Save the access_token from response
export TOKEN="your-access-token-here"

Option B: Via Google OAuth

1. Set up Google OAuth credentials (see IMPLEMENTATION_GUIDE.md)
2. Use the web interface or OAuth flow to register

Step 5: Import Mail Accounts

Create a migration script to import your existing accounts:

# Create migration script
cat > migrate_accounts.sh << 'EOF'
#!/bin/bash

TOKEN="your-access-token"
API_URL="http://localhost:8000/api/v1"

# Function to add a mail account
add_account() {
    local name=$1
    local host=$2
    local port=$3
    local user=$4
    local pass=$5
    local forward_to=$6
    
    curl -X POST "$API_URL/mail-accounts" \
      -H "Authorization: Bearer $TOKEN" \
      -H "Content-Type: application/json" \
      -d "{
        \"name\": \"$name\",
        \"email_address\": \"$user\",
        \"protocol\": \"pop3_ssl\",
        \"host\": \"$host\",
        \"port\": $port,
        \"use_ssl\": true,
        \"use_tls\": false,
        \"username\": \"$user\",
        \"password\": \"$pass\",
        \"forward_to\": \"$forward_to\",
        \"is_enabled\": true,
        \"check_interval_minutes\": 5,
        \"max_emails_per_check\": 50,
        \"delete_after_forward\": true
      }"
    
    echo ""
}

# Import accounts from old .env
# Account 1
add_account \
    "My Email Account" \
    "$POP3_ACCOUNT_1_HOST" \
    "$POP3_ACCOUNT_1_PORT" \
    "$POP3_ACCOUNT_1_USER" \
    "$POP3_ACCOUNT_1_PASSWORD" \
    "$GMAIL_DESTINATION"

# Account 2 (if exists)
if [ -n "$POP3_ACCOUNT_2_HOST" ]; then
    add_account \
        "Second Account" \
        "$POP3_ACCOUNT_2_HOST" \
        "$POP3_ACCOUNT_2_PORT" \
        "$POP3_ACCOUNT_2_USER" \
        "$POP3_ACCOUNT_2_PASSWORD" \
        "$GMAIL_DESTINATION"
fi

# Add more accounts as needed...

EOF

chmod +x migrate_accounts.sh

# Source old environment and run migration
source .env.legacy.backup
./migrate_accounts.sh

Step 6: Verify Configuration

# List imported accounts
curl -X GET http://localhost:8000/api/v1/mail-accounts \
  -H "Authorization: Bearer $TOKEN" | jq .

# Test connection for first account
curl -X POST http://localhost:8000/api/v1/mail-accounts/test \
  -H "Authorization: Bearer $TOKEN" \
  -H "Content-Type: application/json" \
  -d @test_connection.json

Step 7: Monitor Processing

# Check Celery worker logs
docker-compose -f docker-compose.new.yml logs -f celery-worker

# Watch for processing runs
watch -n 5 'curl -s -X GET http://localhost:8000/api/v1/mail-accounts \
  -H "Authorization: Bearer $TOKEN" | jq ".[].last_check_at"'

Step 8: Parallel Testing (Recommended)

Run both systems in parallel for a few days:

# Keep old system running
docker-compose -f docker-compose.yml ps

# Run new system on different ports
# Edit docker-compose.new.yml to use port 8001 if needed

# Compare logs and results
diff <(docker-compose -f docker-compose.yml logs) \
     <(docker-compose -f docker-compose.new.yml logs)

Step 9: Decommission Old System

Once confident the new system works:

# Stop old container
docker-compose -f docker-compose.yml down

# Archive old configuration
mkdir -p archive
mv pop3_forwarder.py archive/
mv .env.legacy.backup archive/
mv docker-compose.yml archive/docker-compose.legacy.yml

# Update main docker-compose
mv docker-compose.new.yml docker-compose.yml

Multi-User Migration

If migrating for multiple users (e.g., family members):

For Your Wife's Account

# She needs to register her own account
curl -X POST http://localhost:8000/api/v1/auth/register \
  -H "Content-Type: application/json" \
  -d '{
    "email": "wife@example.com",
    "password": "her-secure-password",
    "full_name": "Wife Name"
  }'

# She logs in to get her token
curl -X POST http://localhost:8000/api/v1/auth/login \
  -H "Content-Type: application/json" \
  -d "username=wife@example.com&password=her-secure-password"

WIFE_TOKEN="her-access-token"

# Add her mail accounts using her token
curl -X POST http://localhost:8000/api/v1/mail-accounts \
  -H "Authorization: Bearer $WIFE_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{
    "name": "Wife Email",
    "email_address": "wife@provider.com",
    "protocol": "pop3_ssl",
    "host": "pop.provider.com",
    "port": 995,
    "use_ssl": true,
    "username": "wife@provider.com",
    "password": "her-email-password",
    "forward_to": "wife@gmail.com",
    "is_enabled": true
  }'

Configuration Mapping

Environment Variables to Database

Legacy (.env)	New System (Database)
POP3_ACCOUNT_N_*	mail_accounts table per user
GMAIL_DESTINATION	forward_to field in mail_accounts
CHECK_INTERVAL_MINUTES	Per-account check_interval_minutes
MAX_EMAILS_PER_RUN	Per-account max_emails_per_check
SMTP_USER / SMTP_PASSWORD	To be configured per user or globally

Feature Mapping

Legacy Feature	New Feature	Notes
Multiple POP3 accounts	Mail Accounts API	Per-user, unlimited (based on tier)
Single Gmail destination	Per-account forwarding	Each account can forward to different address
Fixed check interval	Configurable per account	More flexibility
Postmark notifications	Apprise notifications	More channels (Telegram, Slack, etc.)
Environment config	Database + Web UI	Easier management
No authentication	JWT + OAuth2	Secure multi-user access
No user limits	Subscription tiers	Free: 1, Basic: 5, Pro: 20, Enterprise: 100

Troubleshooting Migration

Issue: Cannot connect to database

# Check database is running
docker-compose -f docker-compose.new.yml ps postgres

# Check connection
docker-compose -f docker-compose.new.yml exec postgres psql -U postgres -c "SELECT 1;"

Issue: Migrations fail

# Reset database (⚠️ deletes all data)
docker-compose -f docker-compose.new.yml down -v
docker-compose -f docker-compose.new.yml up -d postgres
sleep 5
docker-compose -f docker-compose.new.yml exec backend alembic upgrade head

Issue: Emails not being processed

# Check Celery worker
docker-compose -f docker-compose.new.yml logs celery-worker

# Manually trigger processing
curl -X POST http://localhost:8000/api/v1/admin/trigger-processing \
  -H "Authorization: Bearer $TOKEN"

Issue: Authentication fails

# Verify token is valid
curl -X GET http://localhost:8000/api/v1/users/me \
  -H "Authorization: Bearer $TOKEN"

# If expired, login again
curl -X POST http://localhost:8000/api/v1/auth/login \
  -H "Content-Type: application/json" \
  -d "username=your-email&password=your-password"

Rollback Plan

If you need to rollback to the old system:

# Stop new system
docker-compose -f docker-compose.new.yml down

# Restore old configuration
cp archive/.env.legacy.backup .env
cp archive/docker-compose.legacy.yml docker-compose.yml

# Start old system
docker-compose up -d

# Verify it's working
docker-compose logs -f

Post-Migration Checklist

• All mail accounts imported and tested
• Email processing verified
• Notifications configured
• Old system stopped and archived
• Documentation updated
• Users trained on new interface
• Monitoring set up
• Backups configured
• SSL/TLS certificates installed (for production)
• OAuth credentials configured

Getting Help

If you encounter issues during migration:

1. Check logs: docker-compose -f docker-compose.new.yml logs
2. Review IMPLEMENTATION_GUIDE.md
3. Check ARCHITECTURE.md for system overview
4. Open an issue on GitHub with:
   • Error messages
   • Steps to reproduce
   • Configuration (without passwords)

Benefits After Migration

• ✅ Multi-user support: Each user has own accounts
• ✅ Better security: Encrypted credentials, JWT auth
• ✅ Web interface: Easy configuration (when implemented)
• ✅ API access: Programmatic control
• ✅ Better monitoring: Statistics, logs per account
• ✅ Scalability: Can handle many users
• ✅ Subscription management: Monetization ready
• ✅ More protocols: POP3 and IMAP support
• ✅ Auto-detection: Server settings for common providers
• ✅ Flexible notifications: Multiple channels via Apprise

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Need Help? Open an issue or discussion on GitHub!

Last Updated: 2026-02-01