Get Linux Debian system stats as a json string

system-json.sh

#!/bin/bash

# Get used RAM percentage
ram_used=$(free | awk '/Mem:/ {printf "%.2f", $3/$2 * 100}')

# Get average CPU usage percentage
cpu_used=$(top -bn2 -d 0.5 | grep "Cpu(s)" | tail -n 1 | awk '{print $2 + $4}')

# Get used disk space percentage across all disks
disk_used=$(df -h --total | awk '/total/ {print $5}' | sed 's/%//')

# Construct and print JSON string
json_output=$(cat <<EOF
{
  "ram_used": ${ram_used},
  "cpu_used": ${cpu_used},
  "disk_used": ${disk_used}
}
EOF
)

echo "$json_output"