Using pdsh to fetch multiple servers status and output JSON format data

fetch_servers.sh

#!/bin/bash
status_file='./status'
status_json_file='./status.json'

hosts="cml[4,22]"
cmd_hostname="cat /etc/hostname | tr '\n' ','"
cmd_uptime_and_avgload="uptime | sed 's/[0-9]*:[0-9]*,//' | sed 's/.*up//' | sed 's/load average://' | tr '\n' ','"
cmd_cpuinfo="cat /proc/cpuinfo | grep processor | wc -l | tr '\n' ','"
cmd_meminfo="cat /proc/meminfo | egrep '^MemTotal|^MemAvailable|^SwapTotal|^SwapFree|^Cached' | tr 'kB' ' ' | awk -F ':' '{printf(\$2\",\")}'"
cmd_lastupdate="date +'%H:%M:%S'"

function fetch_info {
  cmd="$cmd_hostname; $cmd_uptime_and_avgload; $cmd_cpuinfo; $cmd_meminfo; $cmd_lastupdate"
  header="Server,Uptime,Users,1m Load,5m Load,15m Load,CPU cores,MemTotal,MemAvailable,SwapTotal,SwapFree,Cached,Update Time"

  echo $header > $status_file
  pdsh -w $hosts -N -R ssh $cmd >> $status_file
  cat $status_file | jq -sR '[sub("\n$";"") | splits("\n") | sub("^ +";"") | [splits(",")]] | .[0] as $header | .[1:] | [.[] | [. as $x | range($header | length) | {"key": $header[.], "value": $x[.]|sub("^ +";"")}] | from_entries]' > $status_json_file
}

while true;
do
  fetch_info
  sleep 5
done