tor-guard-relay/docs/MIGRATION.md

Migration Guide - Tor Guard Relay

This document provides general migration guidance for Tor Guard Relay deployments.

For specific v1.1.0 → >=v1.1.1 migration, see MIGRATION-V1.1.X.md.

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📋 General Migration Principles

1. Always Backup First

# Backup data volume
docker run --rm \
  -v <volume-name>:/data \
  -v /tmp:/backup \
  alpine:3.22.2 tar czf /backup/tor-backup-$(date +%Y%m%d).tar.gz /data

# Verify backup
ls -lh /tmp/tor-backup-*.tar.gz

# Save fingerprint
docker run --rm -v <volume-name>:/data alpine:3.22.2 cat /data/fingerprint > /tmp/fingerprint-backup.txt

2. Fingerprint Preservation

Your relay identity is stored in:

• /var/lib/tor/keys/secret_id_key (RSA identity)
• /var/lib/tor/keys/ed25519_master_id_secret_key (Ed25519 identity)
• /var/lib/tor/pt_state/obfs4_state.json (bridge credentials, bridges only)

CRITICAL: These files must be preserved or your relay will get a new fingerprint.

3. Configuration Approaches

Recommended: Mounted Config File

volumes:
  - type: bind
    source: /path/to/relay.conf
    target: /etc/tor/torrc
    read_only: true

Alternative: Environment Variables

environment:
  - TOR_RELAY_MODE=guard
  - TOR_NICKNAME=MyRelay
  - TOR_CONTACT_INFO=email@example.com

Priority: Mounted file > ENV variables

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🔄 Migration Scenarios

Scenario 1: Upgrading Between Versions (Same Image)

Example: v1.1.0 → v1.1.1

Steps:

1. Stop container
2. Backup volumes
3. Remove container (docker rm)
4. Pull new image version
5. Create new container with same volumes
6. Verify fingerprint matches

Expected Downtime: 1-5 minutes

See: MIGRATION-V1.1.X.md for detailed instructions

Scenario 2: Migrating from Official Tor Images

Example: thetorproject/obfs4-bridge → r3bo0tbx1/onion-relay

Challenges:

• Different base OS (Debian → Alpine)
• Different user UID (101 → 100)
• Volume ownership needs fixing

Steps:

1. Backup everything
2. Fix volume ownership: chown -R 100:101
3. Create config file (recommended over ENV)
4. Deploy new container
5. Verify fingerprint preserved

Expected Downtime: 5-10 minutes

See: MIGRATION-V1.1.X.md - Migration Path 2

Scenario 3: Changing Relay Type

Example: Guard → Exit, Guard → Bridge

Warning: ⚠️ This changes your relay's role and requires careful consideration.

Steps:

1. Understand legal implications (especially for exit relays)
2. Update configuration
3. Restart container
4. Monitor logs for warnings
5. Wait 24-48 hours for Tor network to update

Fingerprint: Preserved ✅

Scenario 4: Moving to New Server

Steps:

1. On old server:

   • Stop container
   • Backup volume to tarball
   • Transfer tarball to new server

2. On new server:

   • Create volume
   • Restore from tarball
   • Deploy container with same configuration
   • Verify fingerprint

Example:

# Old server - create backup
docker run --rm -v tor-data:/data -v $PWD:/backup alpine:3.22.2 \
  tar czf /backup/tor-data.tar.gz /data

# Transfer tor-data.tar.gz to new server

# New server - restore
docker volume create tor-data
docker run --rm -v tor-data:/data -v $PWD:/backup alpine:3.22.2 \
  tar xzf /backup/tor-data.tar.gz -C /

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⚙️ Container vs Image vs Configuration

Image: The Docker image (r3bo0tbx1/onion-relay:1.1.1)

• Contains Tor binary, scripts, OS
• Immutable
• Can be updated independently

Container: Running instance

• Created from image
• Has specific configuration
• Must be recreated to use new image

Configuration: Your relay settings

• Mounted file (/etc/tor/torrc)
• OR environment variables
• Persists across container recreations

Volumes: Your relay data

• Identity keys
• State information
• Logs
• Persists across container recreations

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🔍 Verification Checklist

After any migration:

• Container starts successfully
• No errors in logs: docker logs <container> | grep -i error
• Fingerprint matches backup
• Configuration loaded correctly
• Bootstrap reaches 100%
• Relay/bridge is reachable
• Diagnostic tools work:
  • docker exec <container> status
  • docker exec <container> health
  • docker exec <container> fingerprint
• Tor Metrics shows relay (after 1-2 hours)

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🛠️ Common Migration Issues

Issue: "Permission denied" Errors

Cause: Volume ownership mismatch

Fix:

# Check ownership
docker run --rm -v <volume>:/data alpine:3.22.2 ls -ldn /data

# Fix if needed (Alpine tor user is UID 100)
docker run --rm -v <volume>:/data alpine:3.22.2 chown -R 100:101 /data

Issue: Fingerprint Changed

Cause: Identity keys not preserved

Fix: Restore from backup:

docker stop <container>
docker run --rm -v <volume>:/data -v /tmp:/backup alpine:3.22.2 \
  sh -c 'rm -rf /data/* && tar xzf /backup/tor-backup-*.tar.gz -C /'
docker start <container>

Issue: Container Restart Loop

Debug:

# Check logs
docker logs <container> --tail 50

# Verify using correct image
docker inspect <container> --format='{{.Image}}'

# Check configuration
docker exec <container> cat /etc/tor/torrc

Common causes:

• Invalid configuration syntax
• Missing required fields
• ENV variable validation failures (use mounted config instead)

Issue: Health Check Failing

Cause: Old versions had hardcoded health check path

Fix: Update to v1.1.1+ which includes smart healthcheck script

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📊 Migration Planning

Before Migration

1. Document current state:

   • Image version
   • Configuration source (file or ENV)
   • Volume names
   • Port mappings
   • Current fingerprint

2. Test plan:

   • What to verify post-migration
   • Rollback procedure
   • Downtime window

3. Communication:

   • Notify users (for bridges)
   • Schedule maintenance window
   • Prepare status updates

During Migration

1. Follow documented procedure
2. Take backups
3. Verify each step
4. Don't skip verification

After Migration

1. Monitor logs for 30 minutes
2. Verify fingerprint
3. Check Tor Metrics after 1-2 hours
4. Update documentation
5. Keep backups for 7 days

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🔒 Security Considerations

UID/GID Consistency

This image uses:

• User: tor
• UID: 100
• GID: 101

When migrating from Debian-based images:

• Old UID: 101
• Must fix volume ownership

File Permissions

Expected permissions:

drwx------  /var/lib/tor     (700, owned by tor)
drwxr-xr-x  /var/log/tor     (755, owned by tor)
-rw-------  keys/*           (600, owned by tor)

Capabilities

Minimal required:

cap_add:
  - NET_BIND_SERVICE  # Only if using ports < 1024

Avoid granting unnecessary capabilities.

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📚 Resources

• v1.1.0 → v1.1.1 Migration: MIGRATION-V1.1.X.md
• Deployment Guide: DEPLOYMENT.md
• Troubleshooting: TROUBLESHOOTING-BRIDGE-MIGRATION.md
• Tools Documentation: TOOLS.md
• Security Audit: ../SECURITY-AUDIT-REPORT.md

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🆘 Getting Help

If migration fails:

1. Check logs: docker logs <container>
2. Verify backup: ls -lh /tmp/tor-backup-*.tar.gz
3. Restore from backup if needed
4. Consult troubleshooting docs
5. Open GitHub issue with:
   • Migration path (what → what)
   • Error messages
   • Log output
   • Configuration (redact sensitive info)

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⚡ Quick Reference

Common Commands

# Backup
docker run --rm -v <vol>:/data -v /tmp:/backup alpine:3.22.2 tar czf /backup/backup.tar.gz /data

# Restore
docker run --rm -v <vol>:/data -v /tmp:/backup alpine:3.22.2 tar xzf /backup/backup.tar.gz -C /

# Fix ownership (Alpine)
docker run --rm -v <vol>:/data alpine:3.22.2 chown -R 100:101 /data

# Get fingerprint
docker exec <container> fingerprint

# Check health
docker exec <container> health | jq .

# Full status
docker exec <container> status

Version-Specific Migrations

From	To	Guide
v1.1.0	>=v1.1.1	MIGRATION-V1.1.X.md
Official bridge	v1.1.1	MIGRATION-V1.1.X.md - Path 2
Future	Future	This document + version-specific guide

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Last Updated: 2025-12-05