This script goes in etc/rc.local to show ip address at boot up.
# Print the IP address
_IP=$(hostname -I) || true
if [ "$_IP" ]; then
printf "My IP address is %s\n" "$_IP"
printf "My IP address is %s\n\nRaspbian GNU/Linux\n\n" "$_IP" > /etc/issue
else
printf "Raspbian GNU/Linux\n\n" > /etc/issue
fi
exit 0