feat: improve motd memory usage for lxc

#!/bin/sh

# distribution information

if [ -f /etc/os-release ]; then

  . /etc/os-release

# disk usage

disk_usage=$(df -h / | awk 'NR==2 {print $3 " / " $2 " (" $5 ")"}')

# memory usage

# memory usage (cgroup aware for LXC)

if [ -f /sys/fs/cgroup/memory.current ]; then

  mem_used_kb=$(awk '{print int($1/1024)}' /sys/fs/cgroup/memory.current)

  mem_total_kb=$(awk '/MemTotal/ {print $2}' /proc/meminfo)

  mem_used_mb=$((mem_used_kb / 1024))

  mem_total_mb=$((mem_total_kb / 1024))

  mem_pct=$((mem_used_kb * 100 / mem_total_kb))

  memory_usage="$mem_used_mb MB / $mem_total_mb MB ($mem_pct%)"

else

  memory_usage=$(free -m | awk 'NR==2 {print $3 " MB / " $2 " MB (" int($3/$2*100) "%)"}')

fi

# display motd

echo "Welcome to $(hostname)!"

echo -e "$linux_distribution"

echo "Disk Usage: $disk_usage"

echo "Memory Usage: $memory_usage"

echo ""