Setup the netconsole module to send kernel logs to a remote machine

netconsole.sh

#!/usr/bin/env bash

########
# Script to easily enable netconsole and change kernel verbosity
#
# See http://elinux.org/Debugging_py_printing
#

set -e

declare -A VERBOSITY
VERBOSITY[0]=KERN_EMERG
VERBOSITY[1]=KERN_ALERT
VERBOSITY[2]=KERN_CRIT
VERBOSITY[3]=KERN_ERR
VERBOSITY[4]=KERN_WARNING
VERBOSITY[5]=KERN_NOTICE
VERBOSITY[6]=KERN_INFO
VERBOSITY[7]=KERN_DEBUG

LEVEL=7
ERR=""

if [[ $# -eq 0 ]]; then ERR="Missing required arguments."; fi
if [[ $# -ge 1 ]]; then IP=$1; fi
if [[ $# -ge 2 ]]; then LEVEL=$2; fi
if [[ $# -ge 3 ]]; then ERR="Too many arguments."; fi

if [[ ! " ${!VERBOSITY[@]} " =~ " $LEVEL " ]]; then
    ERR="Unknown verbosity level."
fi

if [[ "x$ERR" != "x" ]]; then
    echo "Error: $ERR"
    echo "Usage: $(basename $0) <ip address> [verbosity]"
    echo
    echo "Accepted numeric verbosity levels are:"
    for i in "${!VERBOSITY[@]}"; do
        echo "    $i (${VERBOSITY[$i]})"
    done
    exit 1
fi

echo "Sending console output via UDP to $IP:6666"
modprobe netconsole netconsole=@/,@${IP}/

echo "Increasing console verbosity to $LEVEL (${VERBOSITY[$LEVEL]})"
echo $LEVEL > /proc/sys/kernel/printk

echo "Please run \`netcat -u -l 6666\` on the target machine at $IP now."