c-relay/systemd/README.md

C Nostr Relay - SystemD Deployment

This directory contains files for deploying the C Nostr Relay as a systemd service with the new Event-Based Configuration System.

Overview

The C Nostr Relay now uses a revolutionary zero-configuration approach where all configuration is stored as Nostr events (kind 33334) in the database. No configuration files or command line arguments are needed.

Files

• c-relay.service - SystemD service unit file
• install-service.sh - Automated installation script
• uninstall-service.sh - Automated uninstall script
• README.md - This documentation

Quick Installation

1. Build the project:

   make clean && make
   

2. Install as systemd service:

   sudo systemd/install-service.sh
   

3. Start the service:

   sudo systemctl start c-relay
   

4. Check admin keys (IMPORTANT!):

   sudo journalctl -u c-relay --since="1 hour ago" | grep "Admin Private Key"
   

Event-Based Configuration System

How It Works

• Zero Configuration: No config files or command line arguments needed
• First-Time Startup: Automatically generates admin and relay keypairs
• Database Naming: Creates database as <relay_pubkey>.nrdb
• Configuration Storage: All settings stored as kind 33334 Nostr events
• Real-Time Updates: Configuration changes applied instantly via WebSocket

First Startup

On first startup, the relay will:

1. Generate cryptographically secure admin and relay keypairs
2. Create database file named with relay pubkey: <relay_pubkey>.nrdb
3. Create initial configuration event (kind 33334) with default values
4. Display admin private key once in the logs
5. Start WebSocket server listening on port 8888

Admin Keys

⚠️ CRITICAL: Save the admin private key displayed during first startup!

# View first startup logs to get admin private key
sudo journalctl -u c-relay --since="1 hour ago" | grep -A 5 "IMPORTANT: SAVE THIS ADMIN PRIVATE KEY"

The admin private key is needed to update relay configuration by sending signed kind 33334 events.

Configuration Management

Viewing Current Configuration

# Find the database file
ls /opt/c-relay/*.nrdb

# View configuration event
sqlite3 /opt/c-relay/<relay_pubkey>.nrdb "SELECT content, tags FROM events WHERE kind = 33334;"

Updating Configuration

Send a new kind 33334 event to the relay via WebSocket:

1. Create new configuration event with updated values
2. Sign with admin private key
3. Send via WebSocket to relay
4. Relay automatically applies changes to running system

Service Management

Basic Commands

# Start service
sudo systemctl start c-relay

# Stop service  
sudo systemctl stop c-relay

# Restart service
sudo systemctl restart c-relay

# Enable auto-start on boot
sudo systemctl enable c-relay

# Check status
sudo systemctl status c-relay

# View logs (live)
sudo journalctl -u c-relay -f

# View recent logs
sudo journalctl -u c-relay --since="1 hour ago"

Log Analysis

# Check for successful startup
sudo journalctl -u c-relay | grep "First-time startup sequence completed"

# Find admin keys
sudo journalctl -u c-relay | grep "Admin Private Key"

# Check configuration updates  
sudo journalctl -u c-relay | grep "Configuration updated via kind 33334"

# Monitor real-time activity
sudo journalctl -u c-relay -f | grep -E "(INFO|SUCCESS|ERROR)"

File Locations

After installation:

• Binary: /opt/c-relay/c_relay_x86
• Database: /opt/c-relay/<relay_pubkey>.nrdb (created automatically)
• Service File: /etc/systemd/system/c-relay.service
• User: c-relay (system user created automatically)

Security Features

The systemd service includes security hardening:

• Runs as dedicated system user c-relay
• NoNewPrivileges=true
• ProtectSystem=strict
• ProtectHome=true
• PrivateTmp=true
• Limited address families (IPv4/IPv6 only)
• Resource limits (file descriptors, processes)

Network Configuration

• Default Port: 8888 (WebSocket)
• Protocol: WebSocket with Nostr message format
• Configuration: Port configurable via kind 33334 events (no restart needed)

Backup and Migration

Backup

The database file contains everything:

# Backup database file
sudo cp /opt/c-relay/*.nrdb /backup/location/

# The .nrdb file contains:
# - All Nostr events
# - Configuration events (kind 33334)  
# - Relay keys and settings

Migration

To migrate to new server:

1. Copy .nrdb file to new server's /opt/c-relay/ directory
2. Install service with install-service.sh
3. Start service - it will automatically detect existing configuration

Troubleshooting

Service Won't Start

# Check service status
sudo systemctl status c-relay

# Check logs for errors
sudo journalctl -u c-relay --no-pager

# Check if binary exists and is executable
ls -la /opt/c-relay/c_relay_x86

# Check permissions
sudo -u c-relay ls -la /opt/c-relay/

Database Issues

# Check if database file exists
ls -la /opt/c-relay/*.nrdb*

# Check database integrity
sqlite3 /opt/c-relay/*.nrdb "PRAGMA integrity_check;"

# View database schema
sqlite3 /opt/c-relay/*.nrdb ".schema"

Configuration Issues

# Check if configuration event exists
sqlite3 /opt/c-relay/*.nrdb "SELECT COUNT(*) FROM events WHERE kind = 33334;"

# View configuration event
sqlite3 /opt/c-relay/*.nrdb "SELECT id, created_at, LENGTH(tags) FROM events WHERE kind = 33334;"

Uninstallation

sudo systemd/uninstall-service.sh

The uninstall script will:

• Stop and disable the service
• Remove service file
• Optionally remove installation directory and data
• Optionally remove service user

Support

For issues with the event-based configuration system:

1. Check service logs: sudo journalctl -u c-relay -f
2. Verify database integrity
3. Ensure admin private key is saved securely
4. Check WebSocket connectivity on port 8888

The relay is designed to be zero-maintenance once deployed. All configuration is managed through Nostr events, enabling dynamic updates without server access.