Run the Tailscale client in a Linux initrd on Debian or Ubuntu.
project page
# Add the repository
sudo mkdir -p --mode=0755 /usr/share/local/keyrings
curl -fsSL https://darkrain42.github.io/tailscale-initramfs/keyring.asc | sudo tee /usr/local/share/keyrings/tailscale-initramfs-keyring.asc >/dev/null
echo 'deb [signed-by=/usr/local/share/keyrings/tailscale-initramfs-keyring.asc] https://darkrain42.github.io/tailscale-initramfs/repo stable main' | sudo tee /etc/apt/sources.list.d/tailscale-initramfs.list >/dev/null

# Install tailscale-initramfs
sudo apt-get update && sudo apt-get install tailscale-initramfs