Raspberry Pi – Dynamic MOTD

Posted on September 12, 2019September 22, 2020 By David Kittell

Similar to UNIX – Set SSH Banner but this will update at every login incase something changes.

mkdir /etc/update-motd.d
cd /etc/update-motd.d
touch 00-header && touch 11-server-info && touch 99-footer
chmod +x /etc/update-motd.d/*
rm /etc/motd
ln -s /var/run/motd /etc/motd

#!/bin/bash
 
# Functions - Start
# Function to convert IP Subnet Mask to CIDR
mask2cdr ()
{
# Assumes there's no "255." after a non-255 byte in the mask
  local x=${1##*255.}
  set -- 0^^^128^192^224^240^248^252^254^ $(( (${#1} - ${#x})*2 )) ${x%%.*}
  x=${1%%$3*}
  echo $(( $2 + (${#x}/4) ))
}
 
# Function to get the the Network IP
networkIP ()
{
  IFS=. read -r i1 i2 i3 i4 <<< ${1}
  IFS=. read -r m1 m2 m3 m4 <<< ${2}
  printf "%d.%d.%d.%d\n" "$((i1 & m1))" "$((i2 & m2))" "$((i3 & m3))" "$((i4 & m4))"
}
# Functions - Stop
 
# Get Hardware Version
RPiVersion=$(cat /proc/device-tree/model)
# echo $RPiVersion
 
#lsb_release -a
OS=$(lsb_release -i | cut -d ":" -f2 | tr -d '[:space:]')
OSCode=$(lsb_release -c | cut -d ":" -f2 | tr -d '[:space:]')
OSVer=$(lsb_release -r | cut -d ":" -f2 | tr -d '[:space:]')
# echo "$OS $OSCode $OSVer"
 
sCPU=$(nproc) # Get number of processors
sRamGB=$(cat /proc/meminfo | grep MemTotal | cut -d ":" -f 2 |  tr -d '[:space:]' | sed 's/.\{2\}$//'  | awk '{$1=$1/(1024^2); print int($1+0.5),"GB";}') # Get amount of RAM in GB
 
# If amount of RAM is less than 1 GB get the amount of RAM in MB
if [ "$sRamGB" == "0 GB" ]; then
  sRamGB=$(cat /proc/meminfo | grep MemTotal | cut -d ":" -f 2 |  tr -d '[:space:]' | sed 's/.\{2\}$//' | awk '{ foo = $1 / 1024 ; print foo " MB" }')
fi
 
sRamUsage=$(free -m | awk 'NR==2{printf "%s/%sMB (%.2f%%)\n", $3,$2,$3*100/$2 }') # Get RAM usage
nUsersLoggedIn=$(users | wc -w) # Get number of users logged in
sProcessorType=$(lscpu | grep op-mode | cut -d ':' -f2 | sed 's/^[ \t]*//;s/[ \t]*$//') # Get Processor Type (32 bit or 64 bit)
# nProcessorLoad=$(top -bn1 | grep load | awk '{printf "%.2f\n", $(NF-2)}' ) # Get Processor/System Load
 
# get the load averages
read one five fifteen rest < /proc/loadavg
 
nProcesses=$(ps aux | wc -l) # Count number of processes running
# Variables - Stop
 
 
banner=$(echo "`date +"%A,%e %B %Y, %r"`\n")
banner=${banner}$(echo "\n")
banner=${banner}$(echo " $RPiVersion\n")
banner=${banner}$(echo " Firmware:\t\t$(uname -r)\n")
banner=${banner}$(echo " OS:\t\t\t$OS $OSCode $OSVer\n")
banner=${banner}$(echo " Hostname:\t\t$(hostname | tr '[:upper:]' '[:lower:]')\n")
banner=${banner}$(echo " Server Uptime:\t\t$(awk '{print int($1/86400)" days "int($1%86400/3600)" hours "int(($1%3600)/60)" minutes "int($1%60)" seconds"}' /proc/uptime)\n")
 
banner=${banner}$(echo "\n System load:\t\t${one}, ${five}, ${fifteen} (1, 5, 15 min)\n")
banner=${banner}$(echo " CPU:\t\t\t$sCPU\t\tProcesses:\t$nProcesses\n")
banner=${banner}$(echo " Memory (RAM):\t\t$sRamGB\t\tUsage:\t\t$sRamUsage\n")
banner=${banner}$(echo " Users logged in:\t$nUsersLoggedIn\n")
 
banner=${banner}$(echo "\n Network Information\n")
 
# Get Network Information - Start
netAdapter=$(ifconfig | grep 'inet' -B1 | grep -v 'inet' | grep -vi 'loopback'  | awk '$1!="inet" && $1!="--"{print $1}' | cut -d ':' -f1)
for val in $(echo $netAdapter); do
  netIP=$(/sbin/ip -o -4 addr list $val | awk '{print $4}' | cut -d/ -f1) # Based on network adapter get the internal IP Address
  netIPv6=$(ifconfig $val | grep 'inet6' | grep 'global'  |awk '{print $2}' | cut -d/ -f1|tr '\n' ' ')
  netMTU=$(cat /sys/class/net/$val/mtu) # Based on the network adapter get the MTU
  netMask=$(ifconfig "$val" | sed -rn '2s/ .*:(.*)$/\1/p') # Based on the network adapter get the subnet mask - Debian 8
 
  if [ -z "${netMask}" ];
  then
    netMask=$(ifconfig "$val" | grep "Mask:" | cut -d ' ' -f13) # Based on the network adapter get the subnet mask - Debian 9
  fi
 
  if [ -z "${netMask}" ];
  then
    netMask=$(ifconfig "$val" | grep "netmask" | cut -d ' ' -f13) # Based on the network adapter get the subnet mask - Debian 9
  fi
  # echo $netMask
 
  netCIDR=$(mask2cdr $netMask) # Calculate the CIDR format
  netWork=$(networkIP $netIP $netMask) # Get the network IP
 
#  netCIDR=$(ipcalc $netIP/$netMask | grep "Netmask:" | cut -d "=" -f2 | cut -d " " -f2 | tr -d '[:space:]')
#  netWork=$(ipcalc $netIP/$netMask | grep "Network:" | cut -d "/" -f1 | cut -d " " -f4 | tr -d '[:space:]')
 
  # Report out the server information defined the variables above
  banner=${banner}$(echo "\n  Adapter:\t$val\n")
  
  if [ ! -z "${netIPv6}" ];
  then
  	banner=${banner}$(echo "  IP v6:\t$netIPv6\n")
  fi

  banner=${banner}$(echo "  IP v4:\t$netIP\n")
  banner=${banner}$(echo "  Mask:\t\t$netMask\n")
  banner=${banner}$(echo "  CIDR:\t\t$netWork/$netCIDR\n")
  banner=${banner}$(echo "  MTU:\t\t$netMTU\n")
 
done
 
# Report the disk/volume space
# banner=${banner}$(echo "Disk Space Information\n")
# banner=${banner}$(df -hTP | grep 'Filesystem\|ext4' | awk '!$2{getline x;$0=$0 x}{printf "\t%-32s %-15s %-8s %-8s %-8s %s\n",$1,$7,$3,$4,$5,$6}')
 
echo -e "$banner"

#!/bin/bash
  
# Functions - Start
# Function to convert IP Subnet Mask to CIDR
mask2cdr ()
{
# Assumes there's no "255." after a non-255 byte in the mask
  local x=${1##*255.}
  set -- 0^^^128^192^224^240^248^252^254^ $(( (${#1} - ${#x})*2 )) ${x%%.*}
  x=${1%%$3*}
  echo $(( $2 + (${#x}/4) ))
}
  
# Function to get the the Network IP
networkIP ()
{
  IFS=. read -r i1 i2 i3 i4 <<< ${1}
  IFS=. read -r m1 m2 m3 m4 <<< ${2}
  printf "%d.%d.%d.%d\n" "$((i1 & m1))" "$((i2 & m2))" "$((i3 & m3))" "$((i4 & m4))"
}
# Functions - Stop
  
# Get Hardware Version
RPiVersion=$(cat /proc/device-tree/model)
# echo $RPiVersion
  
#lsb_release -a
OS=$(lsb_release -i | cut -d ":" -f2 | tr -d '[:space:]')
OSCode=$(lsb_release -c | cut -d ":" -f2 | tr -d '[:space:]')
OSVer=$(lsb_release -r | cut -d ":" -f2 | tr -d '[:space:]')
# echo "$OS $OSCode $OSVer"
  
sCPU=$(nproc) # Get number of processors
sRamGB=$(cat /proc/meminfo | grep MemTotal | cut -d ":" -f 2 |  tr -d '[:space:]' | sed 's/.\{2\}$//'  | awk '{$1=$1/(1024^2); print int($1+0.5),"GB";}') # Get amount of RAM in GB
  
# If amount of RAM is less than 1 GB get the amount of RAM in MB
if [ "$sRamGB" == "0 GB" ]; then
  sRamGB=$(cat /proc/meminfo | grep MemTotal | cut -d ":" -f 2 |  tr -d '[:space:]' | sed 's/.\{2\}$//' | awk '{ foo = $1 / 1024 ; print foo " MB" }')
fi
  
sRamUsage=$(free -m | awk 'NR==2{printf "%s/%sMB (%.2f%%)\n", $3,$2,$3*100/$2 }') # Get RAM usage
nUsersLoggedIn=$(users | wc -w) # Get number of users logged in
sProcessorType=$(lscpu | grep op-mode | cut -d ':' -f2 | sed 's/^[ \t]*//;s/[ \t]*$//') # Get Processor Type (32 bit or 64 bit)
# nProcessorLoad=$(top -bn1 | grep load | awk '{printf "%.2f\n", $(NF-2)}' ) # Get Processor/System Load
  
# get the load averages
read one five fifteen rest < /proc/loadavg
  
nProcesses=$(ps aux | wc -l) # Count number of processes running
# Variables - Stop
  
  
banner=$(echo "`date +"%A,%e %B %Y, %r"`\n")

# Asterisk - Part 1- Start
banner=${banner}$(echo "Welcome to RasPBX - Asterisk for Raspberry Pi\n\n")
banner=${banner}$(echo "RasPBX is based on Debian. The programs included with the Debian GNU/Linux
system are free software; the exact distribution terms for each program are
described in the individual files in /usr/share/doc/*/copyright.\n\n")
banner=${banner}$(echo "RasPBX comes with ABSOLUTELY NO WARRANTY, to the extent permitted by
applicable law.\n\n")
# Asterisk - Part 1- Stop

banner=${banner}$(echo "-----------------------------------------------------------------------------\n")

banner=${banner}$(echo "\n")
banner=${banner}$(echo " $RPiVersion\n")
banner=${banner}$(echo " Firmware:\t\t$(uname -r)\n")
banner=${banner}$(echo " OS:\t\t\t$OS $OSCode $OSVer\n")
banner=${banner}$(echo " Hostname:\t\t$(hostname | tr '[:upper:]' '[:lower:]')\n")
banner=${banner}$(echo " Server Uptime:\t\t$(awk '{print int($1/86400)" days "int($1%86400/3600)" hours "int(($1%3600)/60)" minutes "int($1%60)" seconds"}' /proc/uptime)\n")
  
banner=${banner}$(echo "\n System load:\t\t${one}, ${five}, ${fifteen} (1, 5, 15 min)\n")
banner=${banner}$(echo " CPU:\t\t\t$sCPU\t\tProcesses:\t$nProcesses\n")
banner=${banner}$(echo " Memory (RAM):\t\t$sRamGB\t\tUsage:\t\t$sRamUsage\n")
banner=${banner}$(echo " Users logged in:\t$nUsersLoggedIn\n")

# Report the disk/volume space
banner=${banner}$(echo "\n Disk Space Information\n")
banner=${banner}$(df -hTP | grep 'Filesystem\|ext4' | awk '!$2{getline x;$0=$0 x}{printf "\t\t\t%-32s %-15s %-8s %-8s %-8s %s\n",$1,$7,$3,$4,$5,$6}')

banner=${banner}$(echo "\n Network Information\n")
  
# Get Network Information - Start
netAdapter=$(ifconfig | grep 'inet' -B1 | grep -v 'inet' | grep -vi 'loopback'  | awk '$1!="inet" && $1!="--"{print $1}' | cut -d ':' -f1)
for val in $(echo $netAdapter); do
  netIP=$(/sbin/ip -o -4 addr list $val | awk '{print $4}' | cut -d/ -f1) # Based on network adapter get the internal IP Address
  netIPv6=$(ifconfig $val | grep 'inet6' | grep 'global'  |awk '{print $2}' | cut -d/ -f1|tr '\n' ' ')
  netMTU=$(cat /sys/class/net/$val/mtu) # Based on the network adapter get the MTU
  netMask=$(ifconfig "$val" | sed -rn '2s/ .*:(.*)$/\1/p') # Based on the network adapter get the subnet mask - Debian 8
  
  if [ -z "${netMask}" ];
  then
    netMask=$(ifconfig "$val" | grep "Mask:" | cut -d ' ' -f13) # Based on the network adapter get the subnet mask - Debian 9
  fi
  
  if [ -z "${netMask}" ];
  then
    netMask=$(ifconfig "$val" | grep "netmask" | cut -d ' ' -f13) # Based on the network adapter get the subnet mask - Debian 9
  fi
  # echo $netMask
  
  netCIDR=$(mask2cdr $netMask) # Calculate the CIDR format
  netWork=$(networkIP $netIP $netMask) # Get the network IP
  
#  netCIDR=$(ipcalc $netIP/$netMask | grep "Netmask:" | cut -d "=" -f2 | cut -d " " -f2 | tr -d '[:space:]')
#  netWork=$(ipcalc $netIP/$netMask | grep "Network:" | cut -d "/" -f1 | cut -d " " -f4 | tr -d '[:space:]')
  
  # Report out the server information defined the variables above
  banner=${banner}$(echo "\n  Adapter:\t\t$val\n")
   
  if [ ! -z "${netIPv6}" ];
  then
    banner=${banner}$(echo "  IP v6:\t\t$netIPv6\n")
  fi
 
  banner=${banner}$(echo "  IP v4:\t\t$netIP\n")
  banner=${banner}$(echo "  Mask:\t\t\t$netMask\n")
  banner=${banner}$(echo "  CIDR:\t\t\t$netWork/$netCIDR\n")
  banner=${banner}$(echo "  MTU:\t\t\t$netMTU\n")
  
done
  
banner=${banner}$(echo "\n-----------------------------------------------------------------------------\n")

# Asterisk - Part 2- Start
banner=${banner}$(echo "List of RasPBX specific commands:\n")
banner=${banner}$(echo "-----------------------------------------------------------------------------\n")
banner=${banner}$(echo "raspbx-upgrade      Keep your system up to date with the latest add-ons and security fixes\n")
banner=${banner}$(echo "configure-timezone  Set timezone for both system and PHP\n")
banner=${banner}$(echo "install-fax         Install HylaFAX\n")
banner=${banner}$(echo "add-fax-extension   Add additional fax extension for use with HylaFAX\n")
banner=${banner}$(echo "install-fail2ban    Install Fail2Ban for additional security\n")
banner=${banner}$(echo "install-dongle      Install GSM/3G calling capability with chan_dongle\n")
banner=${banner}$(echo "raspbx-backup       Backup your complete system to an image file\n")
# Asterisk - Part 2- Stop

echo -e "$banner"

sudo chmod -x /etc/update-motd.d/*
sudo chmod +x /etc/update-motd.d/11-server-info

Originally Posted on September 12, 2019
Last Updated on September 22, 2020

All information on this site is shared with the intention to help. Before any source code or program is ran on a production (non-development) system it is suggested you test it and fully understand what it is doing not just what it appears it is doing. I accept no responsibility for any damage you may do with this code.

Related

Code Raspberry Pi Raspbian (Raspberry Pi OS) UNIX UNIX Shell Scripts