🔐 Auto-installer for ssh-key-sync with systemd timer on Linux. Automatically detects OS and architecture, downloads the correct binary, and sets up periodic GitHub SSH key syncing.

setup-ssh-sync.sh

#!/bin/bash

set -e

# === CONFIGURATION ===
VERSION="1.7.3"
USER_NAME="$(whoami)"
GITHUB_USER="hayd1n" # <--- Your GitHub username here

# === Detect OS ===
OS="$(uname | tr '[:upper:]' '[:lower:]')" # linux, darwin

# === Detect ARCH ===
ARCH_RAW="$(uname -m)"
case "$ARCH_RAW" in
x86_64) ARCH="amd64" ;;
aarch64 | arm64) ARCH="arm64" ;;
*)
    echo "❌ Unsupported architecture: $ARCH_RAW"
    exit 1
    ;;
esac

echo "🔍 Detected OS: $OS"
echo "🔍 Detected Architecture: $ARCH"

# === Download & Install ===
cd /tmp
FILENAME="ssh-key-sync_${VERSION}_${OS}_${ARCH}.tar.gz"
URL="https://github.com/shoenig/ssh-key-sync/releases/download/v${VERSION}/${FILENAME}"

echo "⬇️ Downloading $FILENAME ..."
wget -q "$URL" || {
    echo "❌ Download failed. Check if version/arch exists."
    exit 1
}

echo "📦 Extracting..."
sudo tar -C /usr/local/bin -xf "$FILENAME"

# === SSH Setup ===
mkdir -p ~/.ssh
chmod 700 ~/.ssh
touch ~/.ssh/authorized_keys
chmod 600 ~/.ssh/authorized_keys

# === Systemd Service Setup ===
SERVICE_FILE="/etc/systemd/system/ssh-key-sync.service"
TIMER_FILE="/etc/systemd/system/ssh-key-sync.timer"

echo "🛠️ Setting up systemd service..."

sudo bash -c "cat > ${SERVICE_FILE}" <<EOF
[Unit]
Description=Synchronize ssh authorized keys with public keys from github.

[Service]
ExecStart=/usr/local/bin/ssh-key-sync -verbose -system-user ${USER_NAME} -github-user ${GITHUB_USER}
EOF

sudo bash -c "cat > ${TIMER_FILE}" <<EOF
[Unit]
Description=Run ssh-key-sync every 6 hours

[Timer]
OnBootSec=5min
OnUnitActiveSec=6h
Unit=ssh-key-sync.service

[Install]
WantedBy=timers.target
EOF

# === Enable and Start Timer ===
echo "🚀 Enabling and starting systemd timer..."
sudo systemctl daemon-reload
sudo systemctl enable ssh-key-sync.timer
sudo systemctl start ssh-key-sync.service

echo "✅ ssh-key-sync.service started. Checking status..."
sudo systemctl status ssh-key-sync.service --no-pager