Dynamic motd generator for Alpine Linux (/etc/periodic/15min/motd)

motd_generator.sh

#!/bin/sh

UPTIME_DAYS=$(expr `cat /proc/uptime | cut -d '.' -f1` % 31556926 / 86400)
UPTIME_HOURS=$(expr `cat /proc/uptime | cut -d '.' -f1` % 31556926 % 86400 / 3600)
UPTIME_MINUTES=$(expr `cat /proc/uptime | cut -d '.' -f1` % 31556926 % 86400 % 3600 / 60)

cat > /etc/motd << EOF
     %++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++%
     %                                                                            %
     %                                WELCOME!                                    %
     %                                                                            %
     %                            This is a server.                               %
     %                                                                            %
     %                                                                            %
     %+++++++++++++++++++++++++++++++ SERVER INFO ++++++++++++++++++++++++++++++++%
     %                                                                            %
              Name: `hostname`
              Uptime: $UPTIME_DAYS days, $UPTIME_HOURS hours, $UPTIME_MINUTES minutes

              CPU: `cat /proc/cpuinfo | grep 'model name' | head -1 | cut -d':' -f2`
              Memory: `free -m | head -n 2 | tail -n 1 | awk {'print $2'}`M
              Swap: `free -m | tail -n 1 | awk {'print $2'}`M
              Disk: `df -h / | awk '{ a = $2 } END { print a }'`
              Distro: `uname -v` with `uname -r`

              CPU Load: `cat /proc/loadavg | awk '{print $1 ", " $2 ", " $3}'`
              Free Memory: `free -m | head -n 2 | tail -n 1 | awk {'print $4'}`M
              Free Swap: `free -m | tail -n 1 | awk {'print $4'}`M
              Free Disk: `df -h / | awk '{ a = $2 } END { print a }'`

              eth0 Address: `ifconfig eth0 | grep "inet addr" | awk -F: '{print $2}' | awk '{print $1}'`
              eth1 Address: `ifconfig eth1 | grep "inet addr" | awk -F: '{print $2}' | awk '{print $1}'`
              eth2 Address: `ifconfig eth2 | grep "inet addr" | awk -F: '{print $2}' | awk '{print $1}'`
     %                                                                            %
     %++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++%
EOF