#!/bin/bash
# =====================================================
# Proxmox VE: Linux Bridge xx_vmbrmgt erstellen
# IP: 10.60.10.1/24 | Kein physischer Port
# NAT & IP Forwarding aktiviert
# =====================================================

# Root-Check
if [[ $EUID -ne 0 ]]; then
    echo "Bitte als Root ausführen (sudo)"
    exit 1
fi

BRIDGE_NAME="xx_vmbrmgt"
BRIDGE_IP="10.60.10.1/24"
INTERFACES_FILE="/etc/network/interfaces"

echo "==> Backup der interfaces-Datei..."
cp "$INTERFACES_FILE" "${INTERFACES_FILE}.bak.$(date +%Y%m%d-%H%M)"

echo "==> Bridge $BRIDGE_NAME in $INTERFACES_FILE eintragen..."

cat <<EOF >> "$INTERFACES_FILE"

# --------------------------------------------------
# VM Bridge $BRIDGE_NAME
auto $BRIDGE_NAME
iface $BRIDGE_NAME inet static
        address $BRIDGE_IP
        bridge-ports none
        bridge-stp off
        bridge-fd 0
        post-up echo 1 > /proc/sys/net/ipv4/ip_forward
        post-up iptables -t nat -A POSTROUTING -s '10.60.10.0/24' -o vmbr0 -j MASQUERADE
        post-down iptables -t nat -F
EOF

echo "==> Bridge $BRIDGE_NAME konfiguriert."

# Bridge direkt aktivieren
echo "==> Bridge $BRIDGE_NAME aktivieren..."
ifup $BRIDGE_NAME

echo "✔ Bridge $BRIDGE_NAME ist jetzt aktiv!"