Hardened Zebra Full Node

• Uses a dedicated unprivileged user + kernel-level systemd sandboxing (same isolation as Docker).
• RPC is localhost-only with secure cookie auth (default & recommended).

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Prerequisites

• any Ubuntu-based distro
• Rust toolchain installed (rustup + cargo)
• At least 300 GB free disk space (/var partition)

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One-Time Setup (Run as your normal user)

1. Update system & install build dependencies

sudo apt update && sudo apt install -y build-essential pkg-config libclang-dev clang libssl-dev protobuf-compiler

Update Rust and install latest zebrad (v4.3.0+)

rustup update
cargo install --locked --force zebrad
sudo cp ~/.cargo/bin/zebrad /usr/local/bin/zebrad
sudo chown root:root /usr/local/bin/zebrad
sudo chmod 755 /usr/local/bin/zebrad
zebrad --version

Create dedicated unprivileged zebra user

sudo adduser --system --group --no-create-home --shell /usr/sbin/nologin zebra

Create secure data directory

sudo mkdir -p /var/lib/zebrad
sudo chown zebra:zebra /var/lib/zebrad
sudo chmod 700 /var/lib/zebrad

Create secure configuration (/etc/zebrad/zebrad.toml)

sudo mkdir -p /etc/zebrad
sudo tee /etc/zebrad/zebrad.toml > /dev/null <<EOF
[network]
network = "Mainnet"
listen_addr = "0.0.0.0:8233"

[state]
cache_dir = "/var/lib/zebrad"

[rpc]
# Enable RPC on localhost only (never expose to the internet!)
listen_addr = "127.0.0.1:8232"

# Cookie authentication 
enable_cookie_auth = true     # ← uncomment to be explicit
EOF

sudo chown zebra:zebra /etc/zebrad/zebrad.toml
sudo chmod 600 /etc/zebrad/zebrad.toml

Create hardened systemd service

sudo tee /etc/systemd/system/zebrad.service > /dev/null <<EOF
[Unit]
Description=Zebra Zcash Full Node (zebrad)
After=network.target

[Service]
Type=simple
User=zebra
Group=zebra
ExecStart=/usr/local/bin/zebrad --config /etc/zebrad/zebrad.toml start

UMask=0027
ExecStartPost=/bin/chmod 750 /var/lib/zebrad-rpc
ExecStartPost=/bin/chmod 640 /var/lib/zebrad-rpc/.cookie

# Kernel-level sandboxing (makes native zebrad as isolated as Docker)
ProtectSystem=strict
ProtectHome=yes
PrivateTmp=yes
PrivateDevices=yes
NoNewPrivileges=yes
RestrictAddressFamilies=AF_INET AF_INET6
RestrictNamespaces=yes
MemoryDenyWriteExecute=yes
ReadWritePaths=/var/lib/zebrad /var/lib/zebrad-rpc

LimitNOFILE=65535
Restart=on-failure
RestartSec=5s
EOF

sudo systemctl daemon-reload

Daily Usage - Single-Command Workflow

| Action | Command | Notes | |-------------------------|----------------------------------------------|-------| | Start | sudo systemctl start zebrad | One command | | Stop | sudo systemctl stop zebrad | One command | | Status | sudo systemctl status zebrad | Shows if running | | Live logs | journalctl -u zebrad -f -o short-precise | Replaces screen -r | | Get RPC cookie | sudo cat /var/lib/zebrad/.cookie | Only while running |

Convenience aliases (add to ~/.bashrc or ~/.zshrc):

alias zebra-start='sudo systemctl start zebrad'
alias zebra-stop='sudo systemctl stop zebrad'
alias zebra-status='sudo systemctl status zebrad'
alias zebra-logs='journalctl -u zebrad -f'
alias zebra-cookie='sudo cat /var/lib/zebrad/.cookie'