vm-state.sh

#!/bin/bash
servers=$(virsh -rc "qemu:///system" list --all | grep -Ev 'Id|--')

answer='{"servers":[';
while read line; do
    server=$(echo "$line" | awk '{print $2}')
    state=$(echo "$line" | awk '{print $3}')

    if [ "$state" = "running" ]; then
        running="true"
    else
        running="false"
    fi

    if [ "$running" = "true" ]; then
        interfaces=$(virsh -rc 'qemu:///system' domiflist "$server" | grep -Ev 'Interface|--')

        while read interfaceLine; do
            interface=$(echo "$interfaceLine" | awk '{print $1}')
            network=$(echo "$interfaceLine" | awk '{print $3}')
            rx=$(cat "/sys/class/net/$interface/statistics/rx_bytes")
            tx=$(cat "/sys/class/net/$interface/statistics/tx_bytes")

            interfaceString="$interfaceString{\"name\":\"$interface\",\"net\":\"$network\",\"rx\":$rx,\"tx\":$tx},"
        done <<< "$interfaces"
    fi

    interfaceString=$(echo "$interfaceString" | sed 's/,$//')

    answer="$answer{\"name\":\"$server\",\"running\":$running,\"interfaces\":[$interfaceString]},"
    interfaceString=""
done <<<"$servers"

answer=$(echo "$answer" | sed 's/,$//')

answer="$answer]}"

length=${#answer}

echo "Content-Length: $length"
echo "Content-Type: application/json"
echo
echo -ne $answer