#!/bin/bash
# ROLLBACK — restore daemon.json to original (no mtu field)
HOST=$(hostname)
LOG=/volume1/docker/mtu_migration/${HOST}_rollback.log
exec >> "$LOG" 2>&1
echo "[$(date)] $HOST ROLLBACK starting"
cat > /etc/docker/daemon.json << 'DAEMON'
{
  "data-root": "/volume1/docker-root/",
  "storage-driver": "overlay2",
  "dns-search": ["."]
}
DAEMON
echo "[$(date)] daemon.json restored: $(cat /etc/docker/daemon.json)"
systemctl restart docker
sleep 15
echo "[$(date)] Docker status: $(systemctl is-active docker)"
echo "[$(date)] eth0 MTU: $(ip link show eth0 | grep -o 'mtu [0-9]*')"
touch /volume1/docker/mtu_migration/${HOST}_rollback.done
echo "[$(date)] $HOST ROLLBACK COMPLETE"