Add safe br0 bridge setup script

scripts/setup_bridge_br0.sh

@@ -0,0 +1,107 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+IFACE="${1:-enp2s0}"
+BRIDGE="br0"
+NETPLAN_DIR="/etc/netplan"
+BACKUP_DIR="/root/virtuality-netplan-backups/$(date +%Y%m%d_%H%M%S)"
+BRIDGE_FILE="${NETPLAN_DIR}/60-virtuality-br0.yaml"
+ROLLBACK_SCRIPT="/root/virtuality-rollback-netplan.sh"
+
+if [[ "$EUID" -ne 0 ]]; then
+  echo "Ошибка: запусти через sudo: sudo bash scripts/setup_bridge_br0.sh"
+  exit 1
+fi
+
+if ! command -v netplan >/dev/null 2>&1; then
+  echo "Ошибка: netplan не найден. Скрипт рассчитан на Ubuntu/Debian с netplan."
+  exit 1
+fi
+
+if ! ip link show "$IFACE" >/dev/null 2>&1; then
+  echo "Ошибка: интерфейс $IFACE не найден."
+  ip -br a
+  exit 1
+fi
+
+echo "============================================================"
+echo "Virtuality bridge setup"
+echo "============================================================"
+echo "Interface: $IFACE"
+echo "Bridge:    $BRIDGE"
+echo "Backup:    $BACKUP_DIR"
+echo
+
+mkdir -p "$BACKUP_DIR"
+cp -a "$NETPLAN_DIR"/*.yaml "$BACKUP_DIR"/ 2>/dev/null || true
+
+cat > "$ROLLBACK_SCRIPT" <<EOF
+#!/usr/bin/env bash
+set -euo pipefail
+cp -a "$BACKUP_DIR"/*.yaml "$NETPLAN_DIR"/
+rm -f "$BRIDGE_FILE"
+netplan generate
+netplan apply
+echo "Netplan rollback applied from $BACKUP_DIR"
+EOF
+chmod +x "$ROLLBACK_SCRIPT"
+
+cat > "$BRIDGE_FILE" <<EOF
+network:
+  version: 2
+  ethernets:
+    ${IFACE}:
+      dhcp4: false
+      dhcp6: false
+  bridges:
+    ${BRIDGE}:
+      interfaces:
+        - ${IFACE}
+      dhcp4: true
+      dhcp6: false
+      parameters:
+        stp: false
+        forward-delay: 0
+EOF
+
+# Disable DHCP on the original cloud-init ethernet file, if it exists.
+# We keep the file but neutralize enp2s0 to avoid duplicate DHCP on iface and bridge.
+for file in "$NETPLAN_DIR"/*.yaml; do
+  [[ "$file" == "$BRIDGE_FILE" ]] && continue
+  if grep -q "${IFACE}:" "$file"; then
+    cp -a "$file" "${file}.virtuality-before-br0"
+    cat > "$file" <<EOF
+network:
+  version: 2
+  ethernets:
+    ${IFACE}:
+      dhcp4: false
+      dhcp6: false
+EOF
+  fi
+done
+
+echo "[1/4] Generated config:"
+cat "$BRIDGE_FILE"
+
+echo
+ echo "[2/4] Validating netplan..."
+netplan generate
+
+echo
+ echo "[3/4] Applying netplan..."
+netplan apply
+sleep 4
+
+echo
+ echo "[4/4] Result:"
+ip -br a
+ip route
+
+echo
+ echo "============================================================"
+echo "Bridge setup completed"
+echo "============================================================"
+echo "Rollback command if network is broken:"
+echo "sudo $ROLLBACK_SCRIPT"
+echo "============================================================"