Raspberry Pi – Dynamic MOTD

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