Add initial setup for Central DNS and PXE services using dnsmasq

- Created README.md for Central setup documentation.
- Added dnsmasq configuration files and scripts for setting up DNS and PXE booting.
- Implemented nginx configuration to serve PXE boot assets.
- Developed setup.sh script to automate installation and configuration of dnsmasq and nginx.
- Removed outdated dnsmasq setup guide from documentation.

central-setup/dnsmasq/setup.sh

@@ -0,0 +1,58 @@
+#!/bin/bash
+
+# This file to be run on dnsmasq server (Central)
+
+echo "Updating APT repositories."
+sudo apt-get update
+
+echo "Installing dnsmasq and nginx."
+sudo apt install -y dnsmasq nginx
+
+DNSMASQ_SETUP_DIR="/tmp/dnsmasq-setup"
+NODE_IMAGES_DIR="${DNSMASQ_SETUP_DIR}/pxe-web-root"
+
+# Configure nginx.
+echo "Configuring nginx."
+sudo cp "${DNSMASQ_SETUP_DIR}/nginx.conf" /etc/nginx/sites-available/talos
+sudo chown www-data:www-data /etc/nginx/sites-available/talos
+sudo chmod -R 755 /etc/nginx/sites-available/talos
+
+# Copy assets to nginx web root
+echo "Copying Talos PXE boot assets to nginx web root."
+TALOS_PXE_WEB_ROOT="/var/www/html/talos"
+sudo mkdir -p "${TALOS_PXE_WEB_ROOT}"
+sudo rm -rf ${TALOS_PXE_WEB_ROOT}/* # Clean the web root directory
+sudo cp -r ${NODE_IMAGES_DIR}/* "${TALOS_PXE_WEB_ROOT}"
+sudo chown -R www-data:www-data "${TALOS_PXE_WEB_ROOT}"
+sudo chmod -R 755 "${TALOS_PXE_WEB_ROOT}"
+
+# Start nginx service to serve the iPXE script and images
+echo "Starting nginx service."
+sudo ln -s /etc/nginx/sites-available/talos /etc/nginx/sites-enabled/talos > /dev/null 2>&1 || true
+sudo rm -f /etc/nginx/sites-enabled/default
+sudo systemctl reload nginx
+
+# Stop and disable systemd-resolved if it is running
+if systemctl is-active --quiet systemd-resolved; then
+    echo "Stopping and disabling systemd-resolved..."
+    sudo systemctl disable systemd-resolved
+    sudo systemctl stop systemd-resolved
+    # sudo rm -f /etc/resolv.conf
+    echo "systemd-resolved stopped and disabled"
+fi
+
+# Update PXE's iPXE bootloader files.
+# TODO: Put download to cache first.
+echo "Updating iPXE ftpd bootloader files."
+sudo mkdir -p /var/ftpd
+sudo wget http://boot.ipxe.org/ipxe.efi -O /var/ftpd/ipxe.efi
+sudo wget http://boot.ipxe.org/undionly.kpxe -O /var/ftpd/undionly.kpxe
+sudo wget http://boot.ipxe.org/arm64-efi/ipxe.efi -O /var/ftpd/ipxe-arm64.efi
+
+
+# Finally, install and configure DNSMasq.
+echo "Configuring and starting DNSMasq."
+sudo cp "${DNSMASQ_SETUP_DIR}/dnsmasq.conf" /etc/dnsmasq.conf
+sudo systemctl restart dnsmasq
+
+echo "DNSMasq installation and configuration completed successfully."