Fulcrum Electrum Server Setup Script

This Bash script automates the installation and configuration of a high-capacity Fulcrum Electrum server on Debian 12 "Bookworm". It sets up Fulcrum to serve Electrum clients over TCP (port 50001) and SSL (port 443 with Let’s Encrypt), connecting to an existing Bitcoin Core node. The script is optimized for public servers with robust performance settings for high client loads.Features

• Installs Fulcrum with all dependencies, using qmake for compilation.
• Configures Let’s Encrypt SSL for secure connections on port 443.
• Includes high-capacity settings: maxclients=10000, cache=4000, utxo_cache=1000, workers=16, db-num-shards=16.
• Validates Bitcoin RPC credentials.
• Sets up logging to /var/log/fulcrum.log and systemd journal.
• Configures firewall rules (if ufw is installed) for ports 443 and 50001.

Requirements

• OS: Debian 12 "Bookworm".
• Bitcoin Node: Fully synced Bitcoin Core with txindex=1 and server=1.
• Hardware: 8+ CPU cores, 16 GB RAM, 1.3 TB SSD (800 GB for Fulcrum index, ~500 GB for Bitcoin Core).
• Network: Ports 443 (SSL) and 50001 (TCP) open.
• DNS: A public DNS name (e.g., electrum.example.com) resolving to your server’s public IP.
• Permissions: Run as root (via sudo).

Installation

1. Clone or download this repository:

   bash

   git clone <https://github.com/DrekiDegga/fulcrum-install.git>
   cd <fulcrum-install>

2. Make the script executable:

   bash

   chmod +x fulcrum-install.sh

3. Run the script as root:

   bash

   sudo ./fulcrum-install.sh

4. Follow prompts to enter:

   • Public DNS name (e.g., electrum.example.com).
   • Bitcoin RPC username and password (from bitcoin.conf).
   • Bitcoin RPC host (default: 127.0.0.1) and port (default: 8332).

Post-Installation

• Verify Setup:

  • Check service:

    bash

    systemctl status fulcrum

  • Monitor logs:

    bash

    journalctl -u fulcrum -f

    or

    bash

    cat /var/log/fulcrum.log

  • Test connectivity:

    bash

    openssl s_client -connect yourdomain.com:443

    or connect an Electrum wallet to yourdomain.com:443:s or yourdomain.com:50001:t.

• Initial Sync: Indexing takes 1-2 days with utxo_cache=1000. After completion (800 GB in /var/lib/fulcrum), set utxo_cache=0 in /etc/fulcrum/fulcrum.conf for full validation:

  bash

  sudo nano /etc/fulcrum/fulcrum.conf
  sudo systemctl restart fulcrum

Using FulcrumAdmin

The FulcrumAdmin tool, installed with Fulcrum at /usr/local/bin/FulcrumAdmin, allows you to monitor and manage your server, including checking the number of connected clients, server status, and address-specific activity. It communicates with Fulcrum via the admin port (127.0.0.1:8000, configured in /etc/fulcrum/fulcrum.conf).Commands

• Check Connected Clients: View the number and details of currently connected clients (up to maxclients=10000).

  bash

  /usr/local/bin/FulcrumAdmin -p 8000 clients

• Get Server Information: Retrieve server version, uptime, and connection statistics.

  bash

  /usr/local/bin/FulcrumAdmin -p 8000 getinfo

• Query Address Activity: Monitor balance, UTXOs, or transaction history for a specific Bitcoin address to understand client query patterns.

  bash

  /usr/local/bin/FulcrumAdmin -p 8000 query <bitcoin-address>

Configuration

The script generates /etc/fulcrum/fulcrum.conf with:

• Bitcoin Node: Connects via bitcoind=http://user:pass@host:port.
• High-Capacity Settings: Supports 10,000 clients (maxclients=10000), 4 GB cache (cache=4000), 16 workers (workers=16), and 16 database shards (db-num-shards=16).
• SSL: Uses Let’s Encrypt certificates for port 443.
• Logging: Writes to /var/log/fulcrum.log and systemd journal.

Customize settings in /etc/fulcrum/fulcrum.conf for your hardware (e.g., increase cache to 8000 for 64 GB RAM).

Troubleshooting

• Bitcoin Node Issues:

  bash

  bitcoin-cli -rpcuser=<user> -rpcpassword=<pass> -rpcconnect=127.0.0.1 -rpcport=8332 getblockchaininfo

  Ensure "initialblockdownload": false and "chain": "main".

• Connectivity Issues:

  • Verify ports:

    bash

    nc -zv yourdomain.com 443
    nc -zv yourdomain.com 50001

  • Check DNS:

    bash

    dig +short yourdomain.com

• Logs: Review:

  bash

  journalctl -u fulcrum -f

  or

  bash

  cat /var/log/fulcrum.log

Notes

• Performance: Optimized for 16+ cores, 32 GB RAM. Adjust cache, db-max-mem, and db-num-shards for your hardware.
• Security: Uses # for comments in fulcrum.conf (e.g., # High-capacity client limit).

Contributing

Submit issues or pull requests for improvements.