-

#! /bin/bash

# Re-order interfaces on supermicro boxes to ensure eth0/eth1 are the on-board NICs
# Priority given to interfaces with MAC addresses in the SUPERMICRO_ADDRESSES list below

RULES_FILE=$1

if [ ! -f "${RULES_FILE}" ]; then
  echo "Rules file ${RULES_FILE} does not exist! Cannot overwrite"
  exit 1
fi

echo "Re-ordering interfaces..."
HWINFO=$(lshw -class network -quiet)

SUPERMICRO_ADDRESSES=$(cat <<MACS
0c:c4:7a
MACS
)

IFS=$'\n'

SUPERMICRO_INTERFACES=""
OTHER_INTERFACES=""

for IF in $(cat /proc/net/dev | awk '{ print $1 }' | grep -Eo "^eth[[:digit:]]"); do
  MAC=$(ip link show ${IF} | tail -n 1 | awk '{ print $2 }')
  PCI=$(echo -e "${HWINFO}" | grep -B 1 "logical name: ${IF}" | head -n 1 | grep "bus info:" | awk '{ print $3 }')
  
  echo -n "Found ${IF} with MAC ${MAC}, PCI address ${PCI}"
  
  IS_SUPERMICRO=0
  for ADDRESS in $(echo "${SUPERMICRO_ADDRESSES}"); do
    if [ $(echo "${MAC}" | grep -e "^${ADDRESS}") ]; then
      IS_SUPERMICRO=1
    fi
  done
  
  IF_DETAILS="${IF} ${MAC} ${PCI}"
  
  if [ ${IS_SUPERMICRO} -eq 1 ]; then
    echo -n " [Supermicro]"
    SUPERMICRO_INTERFACES="${SUPERMICRO_INTERFACES}"'\n'"${IF_DETAILS}"
  else
    OTHER_INTERFACES="${OTHER_INTERFACES}"'\n'"${IF_DETAILS}"
  fi
  
  echo
done

echo

PERSISTENT_NET_RULES="# Auto generated by reorder-interfaces.sh at $(date)"

IF_COUNTER=0
for IF in $(echo -e "${SUPERMICRO_INTERFACES}\n${OTHER_INTERFACES}"); do
  ETH=$(echo ${IF} | awk '{ print $1 }')
  MAC=$(echo ${IF} | awk '{ print $2 }')
  PCI=$(echo ${IF} | awk '{ print $3 }')
  NEW_ETH="eth${IF_COUNTER}"
  
  echo "Iterfaces ${ETH} (${MAC}) will become ${NEW_ETH} (${PCI})"
  
  IF_COUNTER=$(expr ${IF_COUNTER} + 1)
  
  PERSISTENT_NET_RULES="${PERSISTENT_NET_RULES}\n"'SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="'"${MAC}"'", ATTR{dev_id}=="0x0", ATTR{type}=="1", KERNEL=="eth*", NAME="'"${NEW_ETH}"'"'
done

echo -e "${PERSISTENT_NET_RULES}" > ${RULES_FILE}


# Now configure eth0 to DHCP (puppet will clean this up later)
cat > /etc/network/interfaces <<INTERFACES
auto lo
  iface lo inet loopback
auto eth0
  iface eth0 inet dhcp

INTERFACES